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Abdi AI, Achcar F, Sollelis L, Silva-Filho JL, Mwikali K, Muthui M, Mwangi S, Kimingi HW, Orindi B, Andisi Kivisi C, Alkema M, Chandrasekar A, Bull PC, Bejon P, Modrzynska K, Bousema T, Marti M. Plasmodium falciparum adapts its investment into replication versus transmission according to the host environment. eLife 2023; 12:e85140. [PMID: 36916164 PMCID: PMC10059685 DOI: 10.7554/elife.85140] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/01/2023] [Indexed: 03/14/2023] Open
Abstract
The malaria parasite life cycle includes asexual replication in human blood, with a proportion of parasites differentiating to gametocytes required for transmission to mosquitoes. Commitment to differentiate into gametocytes, which is marked by activation of the parasite transcription factor ap2-g, is known to be influenced by host factors but a comprehensive model remains uncertain. Here, we analyze data from 828 children in Kilifi, Kenya with severe, uncomplicated, and asymptomatic malaria infection over 18 years of falling malaria transmission. We examine markers of host immunity and metabolism, and markers of parasite growth and transmission investment. We find that inflammatory responses associated with reduced plasma lysophosphatidylcholine levels are associated with markers of increased investment in parasite sexual reproduction (i.e. transmission investment) and reduced growth (i.e. asexual replication). This association becomes stronger with falling transmission and suggests that parasites can rapidly respond to the within-host environment, which in turn is subject to changing transmission.
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Affiliation(s)
- Abdirahman I Abdi
- KEMRI-Wellcome Trust Research ProgrammeKilifiKenya
- Pwani University Biosciences Research Centre, Pwani UniversityKilifiKenya
| | - Fiona Achcar
- Wellcome Center for Integrative Parasitology, University of GlasgowGlasgowUnited Kingdom
- Institute of Parasitology, Vetsuisse and Medical Faculty, University of ZurichZurichSwitzerland
| | - Lauriane Sollelis
- Wellcome Center for Integrative Parasitology, University of GlasgowGlasgowUnited Kingdom
- Institute of Parasitology, Vetsuisse and Medical Faculty, University of ZurichZurichSwitzerland
| | - João Luiz Silva-Filho
- Wellcome Center for Integrative Parasitology, University of GlasgowGlasgowUnited Kingdom
- Institute of Parasitology, Vetsuisse and Medical Faculty, University of ZurichZurichSwitzerland
| | | | | | | | | | | | - Cheryl Andisi Kivisi
- KEMRI-Wellcome Trust Research ProgrammeKilifiKenya
- Pwani University Biosciences Research Centre, Pwani UniversityKilifiKenya
| | - Manon Alkema
- Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Amrita Chandrasekar
- Wellcome Center for Integrative Parasitology, University of GlasgowGlasgowUnited Kingdom
| | - Peter C Bull
- KEMRI-Wellcome Trust Research ProgrammeKilifiKenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research ProgrammeKilifiKenya
| | - Katarzyna Modrzynska
- Wellcome Center for Integrative Parasitology, University of GlasgowGlasgowUnited Kingdom
| | - Teun Bousema
- Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Matthias Marti
- Wellcome Center for Integrative Parasitology, University of GlasgowGlasgowUnited Kingdom
- Institute of Parasitology, Vetsuisse and Medical Faculty, University of ZurichZurichSwitzerland
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Odera DO, Tuju J, Mwai K, Nkumama IN, Fürle K, Chege T, Kimathi R, Diehl S, Musasia FK, Rosenkranz M, Njuguna P, Hamaluba M, Kapulu MC, Frank R, Osier FHA, Abdi AI, Chi PC, de Laurent Z, Jao I, Kamuya D, Kamuyu G, Makale J, Murungi L, Musyoki J, Muthui M, Mwacharo J, Kariuki S, Mwanga D, Mwongeli J, Ndungu F, Njue M, Nyangweso G, Kimani D, Ngoi JM, Musembi J, Ngoto O, Otieno E, Ooko M, Shangala J, Wambua J, Mohammed KS, Omuoyo D, Mosobo M, Kibinge N, Kinyanjui S, Bejon P, Lowe B, Marsh K, Marsh V, Abebe Y, Billingsley PF, Sim BKL, Hoffman SL, James ER, Richie TL, Audi A, Olewe F, Oloo J, Ongecha J, Ongas MO, Koskei N, Bull PC, Hodgson SH, Kivisi C, Imwong M, Murphy SC, Ogutu B, Tarning J, Winterberg M, Williams TN. Anti-merozoite antibodies induce natural killer cell effector function and are associated with immunity against malaria. Sci Transl Med 2023; 15:eabn5993. [PMID: 36753561 DOI: 10.1126/scitranslmed.abn5993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Natural killer (NK) cells are potent immune effectors that can be activated via antibody-mediated Fc receptor engagement. Using multiparameter flow cytometry, we found that NK cells degranulate and release IFN-γ upon stimulation with antibody-opsonized Plasmodium falciparum merozoites. Antibody-dependent NK (Ab-NK) activity was largely strain transcending and enhanced invasion inhibition into erythrocytes. Ab-NK was associated with the successful control of parasitemia after experimental malaria challenge in African adults. In an independent cohort study in children, Ab-NK increased with age, was boosted by concurrent P. falciparum infections, and was associated with a lower risk of clinical episodes of malaria. Nine of the 14 vaccine candidates tested induced Ab-NK, including some less well-characterized antigens: P41, P113, MSP11, RHOPH3, and Pf_11363200. These data highlight an important role of Ab-NK activity in immunity against malaria and provide a potential mechanism for evaluating vaccine candidates.
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Affiliation(s)
- Dennis O Odera
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.,Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - James Tuju
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kennedy Mwai
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.,Epidemiology and Biostatistics Division, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Irene N Nkumama
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Kristin Fürle
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Timothy Chege
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Rinter Kimathi
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Stefan Diehl
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Fauzia K Musasia
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Micha Rosenkranz
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Patricia Njuguna
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mainga Hamaluba
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Melissa C Kapulu
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Roland Frank
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Faith H A Osier
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.,Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.,Department of Life Sciences, Imperial College London, UK
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3
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Abdel Hamid MM, Abdelraheem MH, Acheampong DO, Ahouidi A, Ali M, Almagro-Garcia J, Amambua-Ngwa A, Amaratunga C, Amenga-Etego L, Andagalu B, Anderson T, Andrianaranjaka V, Aniebo I, Aninagyei E, Ansah F, Ansah PO, Apinjoh T, Arnaldo P, Ashley E, Auburn S, Awandare GA, Ba H, Baraka V, Barry A, Bejon P, Bertin GI, Boni MF, Borrmann S, Bousema T, Bouyou-Akotet M, Branch O, Bull PC, Cheah H, Chindavongsa K, Chookajorn T, Chotivanich K, Claessens A, Conway DJ, Corredor V, Courtier E, Craig A, D'Alessandro U, Dama S, Day N, Denis B, Dhorda M, Diakite M, Djimde A, Dolecek C, Dondorp A, Doumbia S, Drakeley C, Drury E, Duffy P, Echeverry DF, Egwang TG, Enosse SMM, Erko B, Fairhurst RM, Faiz A, Fanello CA, Fleharty M, Forbes M, Fukuda M, Gamboa D, Ghansah A, Golassa L, Goncalves S, Harrison GLA, Healy SA, Hendry JA, Hernandez-Koutoucheva A, Hien TT, Hill CA, Hombhanje F, Hott A, Htut Y, Hussein M, Imwong M, Ishengoma D, Jackson SA, Jacob CG, Jeans J, Johnson KJ, Kamaliddin C, Kamau E, Keatley J, Kochakarn T, Konate DS, Konaté A, Kone A, Kwiatkowski DP, Kyaw MP, Kyle D, Lawniczak M, Lee SK, Lemnge M, Lim P, Lon C, Loua KM, Mandara CI, Marfurt J, Marsh K, Maude RJ, Mayxay M, Maïga-Ascofaré O, Miotto O, Mita T, Mobegi V, Mohamed AO, Mokuolu OA, Montgomery J, Morang’a CM, Mueller I, Murie K, Newton PN, Ngo Duc T, Nguyen T, Nguyen TN, Nguyen Thi Kim T, Nguyen Van H, Noedl H, Nosten F, Noviyanti R, Ntui VNN, Nzila A, Ochola-Oyier LI, Ocholla H, Oduro A, Omedo I, Onyamboko MA, Ouedraogo JB, Oyebola K, Oyibo WA, Pearson R, Peshu N, Phyo AP, Plowe CV, Price RN, Pukrittayakamee S, Quang HH, Randrianarivelojosia M, Rayner JC, Ringwald P, Rosanas-Urgell A, Rovira-Vallbona E, Ruano-Rubio V, Ruiz L, Saunders D, Shayo A, Siba P, Simpson VJ, Sissoko MS, Smith C, Su XZ, Sutherland C, Takala-Harrison S, Talman A, Tavul L, Thanh NV, Thathy V, Thu AM, Toure M, Tshefu A, Verra F, Vinetz J, Wellems TE, Wendler J, White NJ, Whitton G, Yavo W, van der Pluijm RW. Pf7: an open dataset of Plasmodium falciparum genome variation in 20,000 worldwide samples. Wellcome Open Res 2023; 8:22. [PMID: 36864926 PMCID: PMC9971654 DOI: 10.12688/wellcomeopenres.18681.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2022] [Indexed: 01/18/2023] Open
Abstract
We describe the MalariaGEN Pf7 data resource, the seventh release of Plasmodium falciparum genome variation data from the MalariaGEN network. It comprises over 20,000 samples from 82 partner studies in 33 countries, including several malaria endemic regions that were previously underrepresented. For the first time we include dried blood spot samples that were sequenced after selective whole genome amplification, necessitating new methods to genotype copy number variations. We identify a large number of newly emerging crt mutations in parts of Southeast Asia, and show examples of heterogeneities in patterns of drug resistance within Africa and within the Indian subcontinent. We describe the profile of variations in the C-terminal of the csp gene and relate this to the sequence used in the RTS,S and R21 malaria vaccines. Pf7 provides high-quality data on genotype calls for 6 million SNPs and short indels, analysis of large deletions that cause failure of rapid diagnostic tests, and systematic characterisation of six major drug resistance loci, all of which can be freely downloaded from the MalariaGEN website.
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Affiliation(s)
| | | | - Mohamed Hassan Abdelraheem
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
- Nuclear Applications In Biological Sciences, Sudan Atomic Energy Commission, Khartoum, Sudan
| | - Desmond Omane Acheampong
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Ambroise Ahouidi
- Health Research Epidemiological Surveillance and Training Institute (IRESSEF), Université Cheikh Anta Diop, Dakar, Senegal
| | - Mozam Ali
- Wellcome Sanger Institute, Hinxton, UK
| | | | - Alfred Amambua-Ngwa
- Wellcome Sanger Institute, Hinxton, UK
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Chanaki Amaratunga
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Maryland, USA
| | - Lucas Amenga-Etego
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Ghana
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana
| | - Ben Andagalu
- United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project, Kisumu, Kenya
| | - Tim Anderson
- Texas Biomedical Research Institute, San Antonio, USA
| | | | | | - Enoch Aninagyei
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health & Allied Sciences, Ho, Ghana
| | - Felix Ansah
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Ghana
| | - Patrick O Ansah
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana
| | | | - Paulo Arnaldo
- Instituto Nacional de Saúde (INS), Maputo, Mozambique
| | - Elizabeth Ashley
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Sarah Auburn
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Nuffield Department of Medicine, University of Oxford, UK
| | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Ghana
| | - Hampate Ba
- Institut National de Recherche en Santé Publique, Nouakchott, Mauritania
| | - Vito Baraka
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania
- Department of Epidemiology, International Health Unit, Universiteit Antwerpen, Antwerp, Belgium
| | - Alyssa Barry
- Walter and Eliza Hall Institute, Melbourne, Australia
- Deakin University, Geelong, Australia
- Burnet Institute, Melbourne, Australia
| | - Philip Bejon
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Maciej F Boni
- Nuffield Department of Medicine, University of Oxford, UK
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Teun Bousema
- London School of Hygiene and Tropical Medicine, London, UK
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marielle Bouyou-Akotet
- Department of Parasitology-Mycology, Université des Sciences de la Santé, Libreville, Gabon
| | - Oralee Branch
- NYU School of Medicine Langone Medical Center, New York, USA
| | - Peter C Bull
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Huch Cheah
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | | | | | | | - Antoine Claessens
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
- LPHI, MIVEGEC, INSERM, CNRS, IRD, University of Montpellier, Montpellier, France
| | - David J Conway
- London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - Alister Craig
- Liverpool School of Tropical Medicine, Liverpool, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Program, Blantyre, Malawi
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Souleymane Dama
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Nicholas Day
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Brigitte Denis
- Malawi-Liverpool-Wellcome Trust Clinical Research Program, Blantyre, Malawi
| | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- WorldWide Antimalarial Resistance Network – Asia Regional Centre, Bangkok, Thailand
| | - Mahamadou Diakite
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
- University Clinical Research Center (UCRC), Bamako, Mali
| | - Abdoulaye Djimde
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Arjen Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Seydou Doumbia
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
- University Clinical Research Center (UCRC), Bamako, Mali
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | | | - Patrick Duffy
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Maryland, USA
| | - Diego F Echeverry
- Departamento de Microbiología, Universidad del Valle, Cali, Colombia
- Centro Internacional de Entrenamiento e Investigaciones Médicas - CIDEIM, Cali, Colombia
| | | | | | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | | | - Caterina A Fanello
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Mark Fleharty
- Broad Institute of Harvard and MIT and Harvard, Cambridge, MA, USA
| | | | - Mark Fukuda
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Dionicia Gamboa
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Anita Ghansah
- Nogouchi Memorial Institute for Medical Research, Legon-Accra, Ghana
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | | | - Sara Anne Healy
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Maryland, USA
| | - Jason A Hendry
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Tran Tinh Hien
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Catherine A Hill
- Department of Entomology, Purdue University, West Lafayette, USA
| | - Francis Hombhanje
- Centre for Health Research & Diagnostics, Divine Word University, Madang, Papua New Guinea
| | | | - Ye Htut
- Department of Medical Research, Yangon, Myanmar
| | - Mazza Hussein
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | | | - Deus Ishengoma
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania
- East African Consortium for Clinical Research (EACCR), Dar es Salaam, Tanzania
| | - Scott A Jackson
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA
| | | | | | | | - Claire Kamaliddin
- Institute of Research for Development (IRD), Paris, France
- The University of Calgary, Calgary, Canada
| | - Edwin Kamau
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | | | | | - Drissa S Konate
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Aminatou Kone
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Myat P Kyaw
- Myanmar Oxford Clinical Research Unit, University of Oxford, Yangon, Myanmar
- University of Public Health, Yangon, Myanmar
| | - Dennis Kyle
- University of South Florida, Tampa, USA
- University of Georgia, Athens, USA
| | | | - Samuel K Lee
- Broad Institute of Harvard and MIT and Harvard, Cambridge, MA, USA
| | - Martha Lemnge
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania
| | - Pharath Lim
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Maryland, USA
- Medical Care Development International, Maryland, USA
| | - Chanthap Lon
- National Institute of Allergy and Infectious Diseases, Phnom Penh, Cambodia
| | - Kovana M Loua
- University Gamal Abdel Nasser of Conakry, Conakry, Guinea
- Institut National de Santé Publique, Conakry, Guinea
| | - Celine I Mandara
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania
| | - Jutta Marfurt
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Kevin Marsh
- Nuffield Department of Medicine, University of Oxford, UK
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Richard James Maude
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Harvard TH Chan School of Public Health, Harvard University, Boston, USA
| | - Mayfong Mayxay
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao People's Democratic Republic
- Institute of Research and Education Development (IRED), University of Health Sciences, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Oumou Maïga-Ascofaré
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Research in Tropical Medicine, Kwame Nkrumah University of Sciences and Technology, Kumasi, Ghana
| | - Olivo Miotto
- Wellcome Sanger Institute, Hinxton, UK
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- MRC Centre for Genomics and Global Health, Big Data Institute, Oxford University, Oxford, UK
| | | | - Victor Mobegi
- Department of Biochemistry and Centre for Biotechnology and Bioinformatics, University of Nairobi, Nairobi, Kenya
| | | | - Olugbenga A Mokuolu
- Department of Paediatrics and Child Health, University of Ilorin, Ilorin, Nigeria
| | - Jaqui Montgomery
- Malawi-Liverpool-Wellcome Trust Clinical Research Program, Blantyre, Malawi
- World Mosquito Program, Monash University, Melbourne, Australia
| | - Collins Misita Morang’a
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Ghana
| | - Ivo Mueller
- Walter and Eliza Hall Institute, Melbourne, Australia
- University of Melbourne, Melbourne, Australia
| | | | - Paul N Newton
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao People's Democratic Republic
| | - Thang Ngo Duc
- National Institute of Malariology, Parasitology and Entomology (NIMPE), Hanoi, Vietnam
| | | | - Thuy-Nhien Nguyen
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | | | - Hong Nguyen Van
- National Institute of Malariology, Parasitology and Entomology (NIMPE), Hanoi, Vietnam
| | - Harald Noedl
- MARIB - Malaria Research Initiative Bandarban, Bandarban, Bangladesh
- Medical University of Vienna, Vienna, Austria
| | - Francois Nosten
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | | | | | - Alexis Nzila
- King Fahid University of Petroleum and Minerals (KFUMP), Dhahran, Saudi Arabia
| | | | - Harold Ocholla
- KEMRI Centres for Disease Control and Prevention (CDC) Research Program, Kisumu, Kenya
- Centre for Bioinformatics and Biotechnology, University of Nairobi, Nairobi, Kenya
| | - Abraham Oduro
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana
| | - Irene Omedo
- Wellcome Sanger Institute, Hinxton, UK
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Marie A Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Congo, Democratic Republic
| | | | - Kolapo Oyebola
- Nigerian Institute of Medical Research, Lagos, Nigeria
- Parasitology and Bioinformatics Unit, Faculty of Science, University of Lagos, Lagos, Nigeria
| | | | | | - Norbert Peshu
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Aung P Phyo
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Shoklo Malaria Research Unit, Bangkok, Thailand
| | | | - Ric N Price
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | | | - Huynh Hong Quang
- Institute of Malariology, Parasitology, and Entomology (IMPE) Quy Nhon, Ministry of Health, Quy Nhon, Vietnam
| | - Milijaona Randrianarivelojosia
- Institut Pasteur de Madagascar, Antananarivo, Madagascar
- Universités d'Antananarivo et de Mahajanga, Antananarivo, Madagascar
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | | | | | | | | | - Lastenia Ruiz
- Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | - David Saunders
- Department of Medicine, Uniformed Services University, Bethesda, MD, USA
| | - Alex Shayo
- Nelson Mandela Institute of Science and Technology, Arusha, Tanzania
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | | | - Mahamadou S. Sissoko
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Xin-zhuan Su
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Maryland, USA
| | | | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Arthur Talman
- MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France
| | - Livingstone Tavul
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Ngo Viet Thanh
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Vandana Thathy
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Aung Myint Thu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Mahamoudou Toure
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | | | | | - Joseph Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
- Yale School of Medicine, New Haven, CT, USA
| | - Thomas E Wellems
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Maryland, USA
| | - Jason Wendler
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Maryland, USA
- Seattle Children’s Hospital, Seattle, USA
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | - William Yavo
- University Félix Houphouët-Boigny, Abidjan, Cote d'Ivoire
- Malaria Research and Control Center of the National Institute of Public Health, Abidjan, Cote d'Ivoire
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4
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Kapulu MC, Kimani D, Njuguna P, Hamaluba M, Otieno E, Kimathi R, Tuju J, Sim BKL, Abdi AI, Abebe Y, Bejon P, Billingsley PF, Bull PC, de Laurent Z, Hoffman SL, James ER, Kariuki S, Kinyanjui S, Kivisi C, Makale J, Marsh K, Mohammed KS, Mosobo M, Musembi J, Musyoki J, Muthui M, Mwacharo J, Mwai K, Ngoi JM, Ngoto O, Nkumama I, Ndungu F, Odera D, Ogutu B, Olewe F, Omuoyo D, Ong’echa J, Osier F, Richie TL, Shangala J, Wambua J, Williams TN. Controlled human malaria infection (CHMI) outcomes in Kenyan adults is associated with prior history of malaria exposure and anti-schizont antibody response. BMC Infect Dis 2022; 22:86. [PMID: 35073864 PMCID: PMC8785382 DOI: 10.1186/s12879-022-07044-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/11/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Individuals living in endemic areas acquire immunity to malaria following repeated parasite exposure. We sought to assess the controlled human malaria infection (CHMI) model as a means of studying naturally acquired immunity in Kenyan adults with varying malaria exposure.
Methods
We analysed data from 142 Kenyan adults from three locations representing distinct areas of malaria endemicity (Ahero, Kilifi North and Kilifi South) enrolled in a CHMI study with Plasmodium falciparum sporozoites NF54 strain (Sanaria® PfSPZ Challenge). To identify the in vivo outcomes that most closely reflected naturally acquired immunity, parameters based on qPCR measurements were compared with anti-schizont antibody levels and residence as proxy markers of naturally acquired immunity.
Results
Time to endpoint correlated more closely with anti-schizont antibodies and location of residence than other parasite parameters such as growth rate or mean parasite density. Compared to observational field-based studies in children where 0.8% of the variability in malaria outcome was observed to be explained by anti-schizont antibodies, in the CHMI model the dichotomized anti-schizont antibodies explained 17% of the variability.
Conclusions
The CHMI model is highly effective in studying markers of naturally acquired immunity to malaria.
Trial registration Clinicaltrials.gov number NCT02739763. Registered 15 April 2016
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5
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Ahouidi A, Ali M, Almagro-Garcia J, Amambua-Ngwa A, Amaratunga C, Amato R, Amenga-Etego L, Andagalu B, Anderson TJC, Andrianaranjaka V, Apinjoh T, Ariani C, Ashley EA, Auburn S, Awandare GA, Ba H, Baraka V, Barry AE, Bejon P, Bertin GI, Boni MF, Borrmann S, Bousema T, Branch O, Bull PC, Busby GBJ, Chookajorn T, Chotivanich K, Claessens A, Conway D, Craig A, D'Alessandro U, Dama S, Day NPJ, Denis B, Diakite M, Djimdé A, Dolecek C, Dondorp AM, Drakeley C, Drury E, Duffy P, Echeverry DF, Egwang TG, Erko B, Fairhurst RM, Faiz A, Fanello CA, Fukuda MM, Gamboa D, Ghansah A, Golassa L, Goncalves S, Hamilton WL, Harrison GLA, Hart L, Henrichs C, Hien TT, Hill CA, Hodgson A, Hubbart C, Imwong M, Ishengoma DS, Jackson SA, Jacob CG, Jeffery B, Jeffreys AE, Johnson KJ, Jyothi D, Kamaliddin C, Kamau E, Kekre M, Kluczynski K, Kochakarn T, Konaté A, Kwiatkowski DP, Kyaw MP, Lim P, Lon C, Loua KM, Maïga-Ascofaré O, Malangone C, Manske M, Marfurt J, Marsh K, Mayxay M, Miles A, Miotto O, Mobegi V, Mokuolu OA, Montgomery J, Mueller I, Newton PN, Nguyen T, Nguyen TN, Noedl H, Nosten F, Noviyanti R, Nzila A, Ochola-Oyier LI, Ocholla H, Oduro A, Omedo I, Onyamboko MA, Ouedraogo JB, Oyebola K, Pearson RD, Peshu N, Phyo AP, Plowe CV, Price RN, Pukrittayakamee S, Randrianarivelojosia M, Rayner JC, Ringwald P, Rockett KA, Rowlands K, Ruiz L, Saunders D, Shayo A, Siba P, Simpson VJ, Stalker J, Su XZ, Sutherland C, Takala-Harrison S, Tavul L, Thathy V, Tshefu A, Verra F, Vinetz J, Wellems TE, Wendler J, White NJ, Wright I, Yavo W, Ye H. An open dataset of Plasmodium falciparum genome variation in 7,000 worldwide samples. Wellcome Open Res 2021; 6:42. [PMID: 33824913 PMCID: PMC8008441 DOI: 10.12688/wellcomeopenres.16168.1] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 02/02/2023] Open
Abstract
MalariaGEN is a data-sharing network that enables groups around the world to work together on the genomic epidemiology of malaria. Here we describe a new release of curated genome variation data on 7,000 Plasmodium falciparum samples from MalariaGEN partner studies in 28 malaria-endemic countries. High-quality genotype calls on 3 million single nucleotide polymorphisms (SNPs) and short indels were produced using a standardised analysis pipeline. Copy number variants associated with drug resistance and structural variants that cause failure of rapid diagnostic tests were also analysed. Almost all samples showed genetic evidence of resistance to at least one antimalarial drug, and some samples from Southeast Asia carried markers of resistance to six commonly-used drugs. Genes expressed during the mosquito stage of the parasite life-cycle are prominent among loci that show strong geographic differentiation. By continuing to enlarge this open data resource we aim to facilitate research into the evolutionary processes affecting malaria control and to accelerate development of the surveillance toolkit required for malaria elimination.
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Affiliation(s)
| | | | - Mozam Ali
- Wellcome Sanger Institute, Hinxton, UK
| | - Jacob Almagro-Garcia
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Alfred Amambua-Ngwa
- Wellcome Sanger Institute, Hinxton, UK,Medical Research Council Unit The Gambia, at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Chanaki Amaratunga
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | - Roberto Amato
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Lucas Amenga-Etego
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana,West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Ben Andagalu
- United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project, Kisumu, Kenya
| | | | | | | | | | - Elizabeth A Ashley
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Sarah Auburn
- Menzies School of Health Research, Darwin, Australia,Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana,University of Ghana, Legon, Ghana
| | - Hampate Ba
- Institut National de Recherche en Santé Publique, Nouakchott, Mauritania
| | - Vito Baraka
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania,Department of Epidemiology, International Health Unit, University of Antwerp, Antwerp, Belgium
| | - Alyssa E. Barry
- Deakin University, Geelong, Australia,Burnet Institute, Melbourne, Australia,Walter and Eliza Hall Institute, Melbourne, Australia
| | - Philip Bejon
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Maciej F. Boni
- Nuffield Department of Medicine, University of Oxford, Oxford, UK,Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Teun Bousema
- London School of Hygiene and Tropical Medicine, London, UK,Radboud University Medical Center, Nijmegen, The Netherlands
| | - Oralee Branch
- NYU School of Medicine Langone Medical Center, New York, USA
| | - Peter C. Bull
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya,Department of Pathology, University of Cambridge, Cambridge, UK
| | - George B. J. Busby
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | | | | | - Antoine Claessens
- Medical Research Council Unit The Gambia, at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia,LPHI, MIVEGEC, INSERM, CNRS, IRD, University of Montpellier, Montpellier, France
| | - David Conway
- London School of Hygiene and Tropical Medicine, London, UK
| | - Alister Craig
- Liverpool School of Tropical Medicine, Liverpool, UK,Malawi-Liverpool-Wellcome Trust Clinical Research, Blantyre, Malawi
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia, at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Souleymane Dama
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Nicholas PJ Day
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Brigitte Denis
- Malawi-Liverpool-Wellcome Trust Clinical Research, Blantyre, Malawi
| | - Mahamadou Diakite
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Abdoulaye Djimdé
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | | | - Patrick Duffy
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | - Diego F. Echeverry
- Centro Internacional de Entrenamiento e Investigaciones Médicas - CIDEIM, Cali, Colombia,Universidad Icesi, Cali, Colombia
| | | | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | | | | | - Mark M. Fukuda
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Dionicia Gamboa
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Anita Ghansah
- Nogouchi Memorial Institute for Medical Research, Legon-Accra, Ghana
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | - William L. Hamilton
- Wellcome Sanger Institute, Hinxton, UK,Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | | | - Lee Hart
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Christa Henrichs
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Tran Tinh Hien
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | | | - Christina Hubbart
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Deus S. Ishengoma
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania,East African Consortium for Clinical Research (EACCR), Dar es Salaam, Tanzania
| | - Scott A. Jackson
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA
| | | | - Ben Jeffery
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Anna E. Jeffreys
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Kimberly J. Johnson
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | | | | | - Edwin Kamau
- Walter Reed Army Institute of Research, U.S. Military HIV Research Program, Silver Spring, MD, USA
| | | | - Krzysztof Kluczynski
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Theerarat Kochakarn
- Wellcome Sanger Institute, Hinxton, UK,Mahidol University, Bangkok, Thailand
| | | | - Dominic P. Kwiatkowski
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Myat Phone Kyaw
- The Myanmar Oxford Clinical Research Unit, University of Oxford, Yangon, Myanmar,University of Public Health, Yangon, Myanmar
| | - Pharath Lim
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA,Medical Care Development International, Maryland, USA
| | - Chanthap Lon
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | | | - Oumou Maïga-Ascofaré
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany,Research in Tropical Medicine, Kwame Nkrumah University of Sciences and Technology, Kumasi, Ghana
| | | | | | - Jutta Marfurt
- Menzies School of Health Research, Darwin, Australia
| | - Kevin Marsh
- Nuffield Department of Medicine, University of Oxford, Oxford, UK,African Academy of Sciences, Nairobi, Kenya
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Vientiane, Lao People's Democratic Republic,Institute of Research and Education Development (IRED), University of Health Sciences, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Alistair Miles
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Olivo Miotto
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK,Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Victor Mobegi
- School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Olugbenga A. Mokuolu
- Department of Paediatrics and Child Health, University of Ilorin, Ilorin, Nigeria
| | - Jacqui Montgomery
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Ivo Mueller
- Walter and Eliza Hall Institute, Melbourne, Australia,Barcelona Centre for International Health Research, Barcelona, Spain
| | - Paul N. Newton
- Wellcome Trust-Mahosot Hospital-Oxford Tropical Medicine Research Collaboration, Vientiane, Lao People's Democratic Republic
| | | | - Thuy-Nhien Nguyen
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Harald Noedl
- MARIB - Malaria Research Initiative Bandarban, Bandarban, Bangladesh
| | - Francois Nosten
- Nuffield Department of Medicine, University of Oxford, Oxford, UK,Shoklo Malaria Research Unit, Bangkok, Thailand
| | | | - Alexis Nzila
- King Fahid University of Petroleum and Minerals (KFUMP), Dharhran, Saudi Arabia
| | | | - Harold Ocholla
- KEMRI - Centres for Disease Control and Prevention (CDC) Research Program, Kisumu, Kenya,Centre for Bioinformatics and Biotechnology, University of Nairobi, Nairobi, Kenya
| | - Abraham Oduro
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana
| | - Irene Omedo
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Marie A. Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Congo, Democratic Republic
| | | | - Kolapo Oyebola
- Nigerian Institute of Medical Research, Lagos, Nigeria,Parasitology and Bioinformatics Unit, Faculty of Science, University of Lagos, Lagos, Nigeria
| | - Richard D. Pearson
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Norbert Peshu
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Aung Pyae Phyo
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand,Shoklo Malaria Research Unit, Bangkok, Thailand
| | - Chris V. Plowe
- School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Ric N. Price
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand,Menzies School of Health Research, Darwin, Australia,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | - Milijaona Randrianarivelojosia
- Institut Pasteur de Madagascar, Antananarivo, Madagascar,Universités d'Antananarivo et de Mahajanga, Antananarivo, Madagascar
| | | | | | - Kirk A. Rockett
- Wellcome Sanger Institute, Hinxton, UK,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Lastenia Ruiz
- Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | - David Saunders
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Alex Shayo
- Nelson Mandela Institute of Science and Technology, Arusha, Tanzania
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Victoria J. Simpson
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | | | - Xin-zhuan Su
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | | | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Livingstone Tavul
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Vandana Thathy
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya,Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, USA
| | | | | | - Joseph Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru,Yale School of Medicine, New Haven, CT, USA
| | - Thomas E. Wellems
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | - Jason Wendler
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Ian Wright
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - William Yavo
- University Félix Houphouët-Boigny, Abidjan, Cote d'Ivoire,Malaria Research and Control Center of the National Institute of Public Health, Abidjan, Cote d'Ivoire
| | - Htut Ye
- Department of Medical Research, Yangon, Myanmar
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6
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Ahouidi A, Ali M, Almagro-Garcia J, Amambua-Ngwa A, Amaratunga C, Amato R, Amenga-Etego L, Andagalu B, Anderson TJC, Andrianaranjaka V, Apinjoh T, Ariani C, Ashley EA, Auburn S, Awandare GA, Ba H, Baraka V, Barry AE, Bejon P, Bertin GI, Boni MF, Borrmann S, Bousema T, Branch O, Bull PC, Busby GBJ, Chookajorn T, Chotivanich K, Claessens A, Conway D, Craig A, D'Alessandro U, Dama S, Day NPJ, Denis B, Diakite M, Djimdé A, Dolecek C, Dondorp AM, Drakeley C, Drury E, Duffy P, Echeverry DF, Egwang TG, Erko B, Fairhurst RM, Faiz A, Fanello CA, Fukuda MM, Gamboa D, Ghansah A, Golassa L, Goncalves S, Hamilton WL, Harrison GLA, Hart L, Henrichs C, Hien TT, Hill CA, Hodgson A, Hubbart C, Imwong M, Ishengoma DS, Jackson SA, Jacob CG, Jeffery B, Jeffreys AE, Johnson KJ, Jyothi D, Kamaliddin C, Kamau E, Kekre M, Kluczynski K, Kochakarn T, Konaté A, Kwiatkowski DP, Kyaw MP, Lim P, Lon C, Loua KM, Maïga-Ascofaré O, Malangone C, Manske M, Marfurt J, Marsh K, Mayxay M, Miles A, Miotto O, Mobegi V, Mokuolu OA, Montgomery J, Mueller I, Newton PN, Nguyen T, Nguyen TN, Noedl H, Nosten F, Noviyanti R, Nzila A, Ochola-Oyier LI, Ocholla H, Oduro A, Omedo I, Onyamboko MA, Ouedraogo JB, Oyebola K, Pearson RD, Peshu N, Phyo AP, Plowe CV, Price RN, Pukrittayakamee S, Randrianarivelojosia M, Rayner JC, Ringwald P, Rockett KA, Rowlands K, Ruiz L, Saunders D, Shayo A, Siba P, Simpson VJ, Stalker J, Su XZ, Sutherland C, Takala-Harrison S, Tavul L, Thathy V, Tshefu A, Verra F, Vinetz J, Wellems TE, Wendler J, White NJ, Wright I, Yavo W, Ye H. An open dataset of Plasmodium falciparum genome variation in 7,000 worldwide samples. Wellcome Open Res 2021; 6:42. [PMID: 33824913 PMCID: PMC8008441.2 DOI: 10.12688/wellcomeopenres.16168.2] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2021] [Indexed: 02/02/2023] Open
Abstract
MalariaGEN is a data-sharing network that enables groups around the world to work together on the genomic epidemiology of malaria. Here we describe a new release of curated genome variation data on 7,000 Plasmodium falciparum samples from MalariaGEN partner studies in 28 malaria-endemic countries. High-quality genotype calls on 3 million single nucleotide polymorphisms (SNPs) and short indels were produced using a standardised analysis pipeline. Copy number variants associated with drug resistance and structural variants that cause failure of rapid diagnostic tests were also analysed. Almost all samples showed genetic evidence of resistance to at least one antimalarial drug, and some samples from Southeast Asia carried markers of resistance to six commonly-used drugs. Genes expressed during the mosquito stage of the parasite life-cycle are prominent among loci that show strong geographic differentiation. By continuing to enlarge this open data resource we aim to facilitate research into the evolutionary processes affecting malaria control and to accelerate development of the surveillance toolkit required for malaria elimination.
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Affiliation(s)
| | | | - Mozam Ali
- Wellcome Sanger Institute, Hinxton, UK
| | - Jacob Almagro-Garcia
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Alfred Amambua-Ngwa
- Wellcome Sanger Institute, Hinxton, UK,Medical Research Council Unit The Gambia, at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Chanaki Amaratunga
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | - Roberto Amato
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Lucas Amenga-Etego
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana,West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Ben Andagalu
- United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project, Kisumu, Kenya
| | | | | | | | | | - Elizabeth A Ashley
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Sarah Auburn
- Menzies School of Health Research, Darwin, Australia,Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana,University of Ghana, Legon, Ghana
| | - Hampate Ba
- Institut National de Recherche en Santé Publique, Nouakchott, Mauritania
| | - Vito Baraka
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania,Department of Epidemiology, International Health Unit, University of Antwerp, Antwerp, Belgium
| | - Alyssa E. Barry
- Deakin University, Geelong, Australia,Burnet Institute, Melbourne, Australia,Walter and Eliza Hall Institute, Melbourne, Australia
| | - Philip Bejon
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Maciej F. Boni
- Nuffield Department of Medicine, University of Oxford, Oxford, UK,Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Teun Bousema
- London School of Hygiene and Tropical Medicine, London, UK,Radboud University Medical Center, Nijmegen, The Netherlands
| | - Oralee Branch
- NYU School of Medicine Langone Medical Center, New York, USA
| | - Peter C. Bull
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya,Department of Pathology, University of Cambridge, Cambridge, UK
| | - George B. J. Busby
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | | | | | - Antoine Claessens
- Medical Research Council Unit The Gambia, at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia,LPHI, MIVEGEC, INSERM, CNRS, IRD, University of Montpellier, Montpellier, France
| | - David Conway
- London School of Hygiene and Tropical Medicine, London, UK
| | - Alister Craig
- Liverpool School of Tropical Medicine, Liverpool, UK,Malawi-Liverpool-Wellcome Trust Clinical Research, Blantyre, Malawi
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia, at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Souleymane Dama
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Nicholas PJ Day
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Brigitte Denis
- Malawi-Liverpool-Wellcome Trust Clinical Research, Blantyre, Malawi
| | - Mahamadou Diakite
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Abdoulaye Djimdé
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | | | - Patrick Duffy
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | - Diego F. Echeverry
- Centro Internacional de Entrenamiento e Investigaciones Médicas - CIDEIM, Cali, Colombia,Universidad Icesi, Cali, Colombia
| | | | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | | | | | - Mark M. Fukuda
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Dionicia Gamboa
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Anita Ghansah
- Nogouchi Memorial Institute for Medical Research, Legon-Accra, Ghana
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | - William L. Hamilton
- Wellcome Sanger Institute, Hinxton, UK,Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | | | - Lee Hart
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Christa Henrichs
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Tran Tinh Hien
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | | | - Christina Hubbart
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Deus S. Ishengoma
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania,East African Consortium for Clinical Research (EACCR), Dar es Salaam, Tanzania
| | - Scott A. Jackson
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA
| | | | - Ben Jeffery
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Anna E. Jeffreys
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Kimberly J. Johnson
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | | | | | - Edwin Kamau
- Walter Reed Army Institute of Research, U.S. Military HIV Research Program, Silver Spring, MD, USA
| | | | - Krzysztof Kluczynski
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Theerarat Kochakarn
- Wellcome Sanger Institute, Hinxton, UK,Mahidol University, Bangkok, Thailand
| | | | - Dominic P. Kwiatkowski
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Myat Phone Kyaw
- The Myanmar Oxford Clinical Research Unit, University of Oxford, Yangon, Myanmar,University of Public Health, Yangon, Myanmar
| | - Pharath Lim
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA,Medical Care Development International, Maryland, USA
| | - Chanthap Lon
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | | | - Oumou Maïga-Ascofaré
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany,Research in Tropical Medicine, Kwame Nkrumah University of Sciences and Technology, Kumasi, Ghana
| | | | | | - Jutta Marfurt
- Menzies School of Health Research, Darwin, Australia
| | - Kevin Marsh
- Nuffield Department of Medicine, University of Oxford, Oxford, UK,African Academy of Sciences, Nairobi, Kenya
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Vientiane, Lao People's Democratic Republic,Institute of Research and Education Development (IRED), University of Health Sciences, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Alistair Miles
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Olivo Miotto
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK,Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Victor Mobegi
- School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Olugbenga A. Mokuolu
- Department of Paediatrics and Child Health, University of Ilorin, Ilorin, Nigeria
| | - Jacqui Montgomery
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Ivo Mueller
- Walter and Eliza Hall Institute, Melbourne, Australia,Barcelona Centre for International Health Research, Barcelona, Spain
| | - Paul N. Newton
- Wellcome Trust-Mahosot Hospital-Oxford Tropical Medicine Research Collaboration, Vientiane, Lao People's Democratic Republic
| | | | - Thuy-Nhien Nguyen
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Harald Noedl
- MARIB - Malaria Research Initiative Bandarban, Bandarban, Bangladesh
| | - Francois Nosten
- Nuffield Department of Medicine, University of Oxford, Oxford, UK,Shoklo Malaria Research Unit, Bangkok, Thailand
| | | | - Alexis Nzila
- King Fahid University of Petroleum and Minerals (KFUMP), Dharhran, Saudi Arabia
| | | | - Harold Ocholla
- KEMRI - Centres for Disease Control and Prevention (CDC) Research Program, Kisumu, Kenya,Centre for Bioinformatics and Biotechnology, University of Nairobi, Nairobi, Kenya
| | - Abraham Oduro
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana
| | - Irene Omedo
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Marie A. Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Congo, Democratic Republic
| | | | - Kolapo Oyebola
- Nigerian Institute of Medical Research, Lagos, Nigeria,Parasitology and Bioinformatics Unit, Faculty of Science, University of Lagos, Lagos, Nigeria
| | - Richard D. Pearson
- Wellcome Sanger Institute, Hinxton, UK,MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - Norbert Peshu
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Aung Pyae Phyo
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand,Shoklo Malaria Research Unit, Bangkok, Thailand
| | - Chris V. Plowe
- School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Ric N. Price
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand,Menzies School of Health Research, Darwin, Australia,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | - Milijaona Randrianarivelojosia
- Institut Pasteur de Madagascar, Antananarivo, Madagascar,Universités d'Antananarivo et de Mahajanga, Antananarivo, Madagascar
| | | | | | - Kirk A. Rockett
- Wellcome Sanger Institute, Hinxton, UK,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Lastenia Ruiz
- Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | - David Saunders
- Department of Immunology and Medicine, US Army Medical Component, Armed Forces Research Institute of Medical Sciences (USAMC-AFRIMS), Bangkok, Thailand
| | - Alex Shayo
- Nelson Mandela Institute of Science and Technology, Arusha, Tanzania
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Victoria J. Simpson
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | | | - Xin-zhuan Su
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | | | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Livingstone Tavul
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Vandana Thathy
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya,Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, USA
| | | | | | - Joseph Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru,Yale School of Medicine, New Haven, CT, USA
| | - Thomas E. Wellems
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, USA
| | - Jason Wendler
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Ian Wright
- MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK
| | - William Yavo
- University Félix Houphouët-Boigny, Abidjan, Cote d'Ivoire,Malaria Research and Control Center of the National Institute of Public Health, Abidjan, Cote d'Ivoire
| | - Htut Ye
- Department of Medical Research, Yangon, Myanmar
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7
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Kivisi CA, Muthui M, Hunt M, Fegan G, Otto TD, Githinji G, Warimwe GM, Rance R, Marsh K, Bull PC, Abdi AI. Exploring Plasmodium falciparum Var Gene Expression to Assess Host Selection Pressure on Parasites During Infancy. Front Immunol 2019; 10:2328. [PMID: 31681266 PMCID: PMC6798654 DOI: 10.3389/fimmu.2019.02328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/16/2019] [Indexed: 11/13/2022] Open
Abstract
In sub-Saharan Africa, children below 5 years bear the greatest burden of severe malaria because they lack naturally acquired immunity that develops following repeated exposure to infections by Plasmodium falciparum. Antibodies to the surface of P. falciparum infected erythrocytes (IE) play an important role in this immunity. In children under the age of 6 months, relative protection from severe malaria is observed and this is thought to be partly due to trans-placental acquired protective maternal antibodies. However, the protective effect of maternal antibodies has not been fully established, especially the role of antibodies to variant surface antigens (VSA) expressed on IE. Here, we assessed the immune pressure on parasites infecting infants using markers associated with the acquisition of naturally acquired immunity to surface antigens. We hypothesized that, if maternal antibodies to VSA imposed a selection pressure on parasites, then the expression of a relatively conserved subset of var genes called group A var genes in infants should change with waning maternal antibodies. To test this, we compared their expression in parasites from children between 0 and 12 months and above 12 months of age. The transcript quantity and the proportional expression of group A var subgroup, including those containing domain cassette 13, were positively associated with age during the first year of life, which contrasts with above 12 months. This was accompanied by a decline in infected erythrocyte surface antibodies and an increase in parasitemia during this period. The observed increase in group A var gene expression with age in the first year of life, when the maternal antibodies are waning and before acquisition of naturally acquired antibodies with repeated exposure, is consistent with the idea that maternally acquired antibodies impose a selection pressure on parasites that infect infants and may play a role in protecting these infants against severe malaria.
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Affiliation(s)
- Cheryl A Kivisi
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya.,Pwani University Biosciences Research Centre, Pwani University, Kilifi, Kenya.,Department of Biological Sciences, Pwani University, Kilifi, Kenya
| | | | - Martin Hunt
- Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Greg Fegan
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | - George M Warimwe
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Richard Rance
- Pwani University Biosciences Research Centre, Pwani University, Kilifi, Kenya
| | - Kevin Marsh
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Peter C Bull
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Abdirahman I Abdi
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya.,Pwani University Biosciences Research Centre, Pwani University, Kilifi, Kenya
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8
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Tuju J, Mackinnon MJ, Abdi AI, Karanja H, Musyoki JN, Warimwe GM, Gitau EN, Marsh K, Bull PC, Urban BC. Antigenic cartography of immune responses to Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1). PLoS Pathog 2019; 15:e1007870. [PMID: 31260501 PMCID: PMC6625739 DOI: 10.1371/journal.ppat.1007870] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/12/2019] [Accepted: 05/24/2019] [Indexed: 12/15/2022] Open
Abstract
Naturally acquired clinical immunity to Plasmodium falciparum is partly mediated by antibodies directed at parasite-derived antigens expressed on the surface of red blood cells which mediate disease and are extremely diverse. Unlike children, adults recognize a broad range of variant surface antigens (VSAs) and are protected from severe disease. Though crucial to the design and feasibility of an effective malaria vaccine, it is not yet known whether immunity arises through cumulative exposure to each of many antigenic types, cross-reactivity between antigenic types, or some other mechanism. In this study, we measured plasma antibody responses of 36 children with symptomatic malaria to a diverse panel of 36 recombinant proteins comprising part of the DBLα domain (the 'DBLα-tag') of PfEMP1, a major class of VSAs. We found that although plasma antibody responses were highly specific to individual antigens, serological profiles of responses across antigens fell into one of just two distinct types. One type was found almost exclusively in children that succumbed to severe disease (19 out of 20) while the other occurred in all children with mild disease (16 out of 16). Moreover, children with severe malaria had serological profiles that were narrower in antigen specificity and shorter-lived than those in children with mild malaria. Borrowing a novel technique used in influenza-antigenic cartography-we mapped these dichotomous serological profiles to amino acid sequence variation within a small sub-region of the PfEMP1 DBLα domain. By applying our methodology on a larger scale, it should be possible to identify epitopes responsible for eliciting the protective version of serological profiles to PfEMP1 thereby accelerating development of a broadly effective anti-disease malaria vaccine.
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Affiliation(s)
- James Tuju
- KEMRI-Wellcome Trust Research Programme, Kenya
- Department of Chemistry and Biochemistry, Pwani University, Kilifi, Kenya
| | | | | | | | | | - George M. Warimwe
- KEMRI-Wellcome Trust Research Programme, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Evelyn N. Gitau
- African Population and Health Research Center, Nairobi, Kenya
| | - Kevin Marsh
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Britta C. Urban
- Liverpool School of Tropical Medicine, Department of Tropical Disease Biology, Pembroke Place, Liverpool, United Kingdom
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9
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Abstract
Human malaria is a complex disease that can show a wide array of clinical outcomes, from asymptomatic carriage and chronic infection to acute disease presenting various life-threatening pathologies. The specific outcome of an infection is believed to be determined by a multifactorial interplay between the host and the parasite but with a general trend toward disease attenuation with increasing prior exposure. Therefore, the main burden of malaria in a population can be understood as a function of transmission intensity, which itself is intricately linked to the prevalence of infected hosts and mosquito vectors, the distribution of infection outcomes, and the parasite population diversity. Predicting the long-term impact of malaria intervention measures therefore requires an in-depth understanding of how the parasite causes disease, how this relates to previous exposures, and how different infection pathologies contribute to parasite transmission. Here, we provide a brief overview of recent advances in the molecular epidemiology of clinical malaria and how these might prove to be influential in our fight against this important disease.
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Affiliation(s)
- Mario Recker
- Centre for Mathematics and the Environment, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | - Peter C Bull
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Caroline O Buckee
- Center for Communicable Disease Dynamics, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
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10
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Schieck E, Poole EJ, Rippert A, Peshu J, Sasi P, Borrmann S, Bull PC. Plasmodium falciparum variant erythrocyte surface antigens: a pilot study of antibody acquisition in recurrent natural infections. Malar J 2017; 16:450. [PMID: 29115961 PMCID: PMC5678811 DOI: 10.1186/s12936-017-2097-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/28/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND During intra-erythrocytic replication Plasmodium falciparum escapes the human host immune system by switching expression of variant surface antigens (VSA). Piecemeal acquisition of variant specific antibody responses to these antigens as a result of exposure to multiple re-infections has been proposed to play a role in acquisition of naturally acquired immunity. METHODS Immunofluorescence was used to explore the dynamics of anti-VSA IgG responses generated by children to (i) primary malaria episodes and (ii) recurrent P. falciparum infections. RESULTS Consistent with previous studies on anti-VSA responses, sera from each child taken at the time of recovery from their respective primary infection tended to recognize their own secondary parasites poorly. Additionally, compared to patients with reinfections by parasites of new merozoite surface protein 2 (MSP2) genotypes, baseline sera sampled from patients with persistent infections (recrudescence) tended to have higher recognition of heterologous parasites. This is consistent with the prediction that anti-VSA IgG responses may play a role in promoting chronic asymptomatic infections. CONCLUSIONS This pilot study validates the utility of recurrent natural malaria infections as a functional readout for examining the incremental acquisition of immunity to malaria.
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Affiliation(s)
- Elise Schieck
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Center for Geographic Medicine Research-Coast, P. O. Box 428, Kilifi, 80108, Kenya. .,Institute of Hygiene, University of Heidelberg School of Medicine, 69120, Heidelberg, Germany. .,International Livestock Research Institute, Old Naivasha Road, P.O. Box 30709, Nairobi, 00100, Kenya.
| | - E Jane Poole
- International Livestock Research Institute, Old Naivasha Road, Nairobi, Kenya
| | - Anja Rippert
- Institute of Hygiene, University of Heidelberg School of Medicine, 69120, Heidelberg, Germany.,Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Judy Peshu
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Center for Geographic Medicine Research-Coast, P. O. Box 428, Kilifi, 80108, Kenya
| | - Philip Sasi
- Department of Clinical Pharmacology, School of Medicine, Muhimbili University of Health and Allied Sciences, P.O. Box 65010, Dar es Salaam, Tanzania
| | - Steffen Borrmann
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Center for Geographic Medicine Research-Coast, P. O. Box 428, Kilifi, 80108, Kenya.,German Center for Infection Research (DZIF), Wilhelmstraße 27, 72074, Tübingen, Germany.,Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Peter C Bull
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Center for Geographic Medicine Research-Coast, P. O. Box 428, Kilifi, 80108, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine, Oxford University, Oxford, OX3 7LJ, UK.,Department of Pathology, Cambridge University, Tennis Court Road, Cambridge, CB2 1QP, UK
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11
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Githinji G, Bull PC. A re-assessment of gene-tag classification approaches for describing var gene expression patterns during human Plasmodium falciparum malaria parasite infections. Wellcome Open Res 2017; 2:86. [PMID: 29062916 PMCID: PMC5635463 DOI: 10.12688/wellcomeopenres.12053.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2017] [Indexed: 11/20/2022] Open
Abstract
PfEMP1 are variant parasite antigens that are inserted on the surface of Plasmodium falciparum infected erythrocytes (IE). Through interactions with various host molecules, PfEMP1 mediate IE sequestration in tissues and play a key role in the pathology of severe malaria. PfEMP1 is encoded by a diverse multi-gene family called var. Previous studies have shown that that expression of specific subsets of var genes are associated with low levels of host immunity and severe malaria. However, in most clinical studies to date, full-length var gene sequences were unavailable and various approaches have been used to make comparisons between var gene expression profiles in different parasite isolates using limited information. Several studies have relied on the classification of a 300 - 500 base-pair "DBLα tag" region in the DBLα domain located at the 5' end of most var genes. We assessed the relationship between various DBLα tag classification methods, and sequence features that are only fully assessable through full-length var gene sequences. We compared these different sequence features in full-length var gene from six fully sequenced laboratory isolates. These comparisons show that despite a long history of recombination, DBLα sequence tag classification can provide functional information on important features of full-length var genes. Notably, a specific subset of DBLα tags previously defined as "group A-like" is associated with CIDRα1 domains proposed to bind to endothelial protein C receptor. This analysis helps to bring together different sources of data that have been used to assess var gene expression in clinical parasite isolates.
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Affiliation(s)
- George Githinji
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Peter C Bull
- Department of Pathology, University of Cambridge, Cambridge, UK
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12
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Pieper K, Tan J, Piccoli L, Foglierini M, Barbieri S, Chen Y, Silacci-Fregni C, Wolf T, Jarrossay D, Anderle M, Abdi A, Ndungu FM, Doumbo OK, Traore B, Tran TM, Jongo S, Zenklusen I, Crompton PD, Daubenberger C, Bull PC, Sallusto F, Lanzavecchia A. Public antibodies to malaria antigens generated by two LAIR1 insertion modalities. Nature 2017; 548:597-601. [PMID: 28847005 PMCID: PMC5635981 DOI: 10.1038/nature23670] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/25/2017] [Indexed: 01/07/2023]
Abstract
We previously described two donors in whom the extracellular domain of LAIR1, a
collagen-binding inhibitory receptor encoded on chromosome 191, was inserted between the V and the DJ segments of an antibody. This
insertion generated, through somatic mutations, broadly reactive antibodies against
RIFINs, a type of variant antigen expressed on the surface of Plasmodium
falciparum-infected erythrocytes (IEs)2.
To investigate how frequently such antibodies are produced in response to malaria
infection, we screened plasma from two large cohorts of individuals living in
malaria-endemic regions. We report that 5-10% of malaria-exposed individuals, but none of
the European blood donors tested, have high levels of LAIR1-containing antibodies that
dominate the response to IEs without conferring enhanced protection against febrile
malaria. By analyzing the antibody-producing B cell clones at the protein, cDNA and gDNA
level, we characterized additional LAIR1 insertions between the V and DJ
segments and discovered a second insertion modality whereby the LAIR1
exon encoding the extracellular domain and flanking intronic sequences are inserted into
the switch region. By exon shuffling, this mechanism leads to the production of bispecific
antibodies in which the LAIR1 domain is precisely positioned at the elbow between the VH
and CH1 domains. Additionally, in one donor the gDNA encoding the VH and CH1 domains was
deleted, leading to the production of a camel-like LAIR1-containing antibody. Sequencing
of the switch regions of memory B cells from European blood donors revealed frequent
templated inserts originating from transcribed genes that, in rare cases, comprised exons
with orientation and frame compatible with expression. Collectively, these results reveal
different modalities of LAIR1 insertion that lead to public and dominant
antibodies against IEs and suggest that insertion of templated DNA represents an
additional mechanism of antibody diversification that can be selected in the immune
response against pathogens and exploited for B cell engineering.
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Affiliation(s)
- Kathrin Pieper
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Joshua Tan
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland.,Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
| | - Luca Piccoli
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Mathilde Foglierini
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland.,Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland
| | - Sonia Barbieri
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Yiwei Chen
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland.,Institute for Microbiology, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
| | - Chiara Silacci-Fregni
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Tobias Wolf
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland.,Institute for Microbiology, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
| | - David Jarrossay
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Marica Anderle
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Abdirahman Abdi
- KEMRI-Wellcome Trust Research Programme, CGMRC, PO Box 230, 80108 Kilifi, Kenya
| | - Francis M Ndungu
- KEMRI-Wellcome Trust Research Programme, CGMRC, PO Box 230, 80108 Kilifi, Kenya
| | - Ogobara K Doumbo
- Malaria Research and Training Centre, University of Sciences, Technique, and Technology of Bamako, 91094 Bamako, Mali
| | - Boubacar Traore
- Malaria Research and Training Centre, University of Sciences, Technique, and Technology of Bamako, 91094 Bamako, Mali
| | - Tuan M Tran
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, 46202 Indianapolis, Indiana, USA
| | - Said Jongo
- Ifakara Health Institute, Bagamoyo Clinical Trial Unit, P.O. Box 74, Bagamoyo, Tanzania
| | - Isabelle Zenklusen
- Swiss Tropical and Public Health Institute, Clinical Immunology Unit, 4002 Basel, Switzerland.,University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - Peter D Crompton
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA
| | - Claudia Daubenberger
- Swiss Tropical and Public Health Institute, Clinical Immunology Unit, 4002 Basel, Switzerland.,University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - Peter C Bull
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Federica Sallusto
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland.,Institute for Microbiology, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland.,Institute for Microbiology, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
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13
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Abdi AI, Hodgson SH, Muthui MK, Kivisi CA, Kamuyu G, Kimani D, Hoffman SL, Juma E, Ogutu B, Draper SJ, Osier F, Bejon P, Marsh K, Bull PC. Plasmodium falciparum malaria parasite var gene expression is modified by host antibodies: longitudinal evidence from controlled infections of Kenyan adults with varying natural exposure. BMC Infect Dis 2017; 17:585. [PMID: 28835215 PMCID: PMC5569527 DOI: 10.1186/s12879-017-2686-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 08/15/2017] [Indexed: 11/10/2022] Open
Abstract
Background The PfEMP1 family of Plasmodium falciparum antigens play a key role in pathogenesis of severe malaria through their insertion into the surface of parasite infected erythrocytes, and adhesion to host cells. Previous studies have suggested that parasites expressing PfEMP1 subclasses group A and DC8, associated with severe malaria, may have a growth advantage in immunologically naïve individuals. However, this idea has not been tested in longitudinal studies. Methods Here we assessed expression of the var genes encoding PfEMP1, in parasites sampled from volunteers with varying prior exposure to malaria, following experimental infection by sporozoites (PfSPZ). Using qPCR, we tested for associations between the expression of various var subgroups in surviving parasite populations from each volunteer and 1) the levels of participants’ antibodies to infected erythrocytes before challenge infection and 2) the apparent in vivo parasite multiplication rate. Results We show that 1) expression of var genes encoding for group A and DC8-like PfEMP1 were associated with low levels of antibodies to infected erythrocytes (αIE) before challenge, and 2) expression of a DC8-like CIDRα1.1 domain was associated with higher apparent parasite multiplication rate in a manner that was independent of levels of prior antibodies to infected erythrocytes. Conclusions This study provides insight into the role of antibodies to infected erythrocytes surface antigens in the development of naturally acquired immunity and may help explain why specific PfEMP1 variants may be associated with severe malaria. Trial registration Pan African Clinical Trial Registry: PACTR201211000433272. Date of registration: 10th October 2012.
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Affiliation(s)
- Abdirahman I Abdi
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya. .,Pwani University, P. O. Box 195-80108, Kilifi, Kenya.
| | | | - Michelle K Muthui
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Cheryl A Kivisi
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya.,Pwani University, P. O. Box 195-80108, Kilifi, Kenya
| | - Gathoni Kamuyu
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Domtila Kimani
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | | | - Elizabeth Juma
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya.,Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
| | - Bernhards Ogutu
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya.,Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
| | | | - Faith Osier
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Kevin Marsh
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Peter C Bull
- Department of Pathology, University of Cambridge, 17 Tennis Court Road, Cambridge, CB2 1QP, UK.
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14
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Chan JA, Howell KB, Langer C, Maier AG, Hasang W, Rogerson SJ, Petter M, Chesson J, Stanisic DI, Duffy MF, Cooke BM, Siba PM, Mueller I, Bull PC, Marsh K, Fowkes FJI, Beeson JG. A single point in protein trafficking by Plasmodium falciparum determines the expression of major antigens on the surface of infected erythrocytes targeted by human antibodies. Cell Mol Life Sci 2016; 73:4141-58. [PMID: 27193441 PMCID: PMC5042999 DOI: 10.1007/s00018-016-2267-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 04/22/2016] [Accepted: 05/06/2016] [Indexed: 11/30/2022]
Abstract
Antibodies to blood-stage antigens of Plasmodium falciparum play a pivotal role in human immunity to malaria. During parasite development, multiple proteins are trafficked from the intracellular parasite to the surface of P. falciparum-infected erythrocytes (IEs). However, the relative importance of different proteins as targets of acquired antibodies, and key pathways involved in trafficking major antigens remain to be clearly defined. We quantified antibodies to surface antigens among children, adults, and pregnant women from different malaria-exposed regions. We quantified the importance of antigens as antibody targets using genetically engineered P. falciparum with modified surface antigen expression. Genetic deletion of the trafficking protein skeleton-binding protein-1 (SBP1), which is involved in trafficking the surface antigen PfEMP1, led to a dramatic reduction in antibody recognition of IEs and the ability of human antibodies to promote opsonic phagocytosis of IEs, a key mechanism of parasite clearance. The great majority of antibody epitopes on the IE surface were SBP1-dependent. This was demonstrated using parasite isolates with different genetic or phenotypic backgrounds, and among antibodies from children, adults, and pregnant women in different populations. Comparisons of antibody reactivity to parasite isolates with SBP1 deletion or inhibited PfEMP1 expression suggest that PfEMP1 is the dominant target of acquired human antibodies, and that other P. falciparum IE surface proteins are minor targets. These results establish SBP1 as part of a critical pathway for the trafficking of major surface antigens targeted by human immunity, and have key implications for vaccine development, and quantifying immunity in populations.
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Affiliation(s)
- Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3001, Australia
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Katherine B Howell
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Christine Langer
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3001, Australia
| | - Alexander G Maier
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Wina Hasang
- Department of Medicine, University of Melbourne, Parkville, VIC, Australia
| | - Stephen J Rogerson
- Department of Medicine, University of Melbourne, Parkville, VIC, Australia
| | - Michaela Petter
- Department of Medicine, University of Melbourne, Parkville, VIC, Australia
| | - Joanne Chesson
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | | | - Michael F Duffy
- Department of Medicine, University of Melbourne, Parkville, VIC, Australia
| | - Brian M Cooke
- Programs in Infection and Immunity and Cardiovascular Disease, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
- Department of Microbiology, Monash University, Melbourne, VIC, Australia
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Peter C Bull
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Kevin Marsh
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Freya J I Fowkes
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3001, Australia
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Melbourne School of Public Health, University of Melbourne, Parkville, VIC, Australia
- Department of Epidemiology and Preventive Medicine and Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3001, Australia.
- Department of Medicine, University of Melbourne, Parkville, VIC, Australia.
- Department of Microbiology, Monash University, Melbourne, VIC, Australia.
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15
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Tan J, Bull PC. Agglutination Assays of the Plasmodium falciparum-Infected Erythrocyte. Methods Mol Biol 2015; 1325:115-129. [PMID: 26450384 PMCID: PMC6624126 DOI: 10.1007/978-1-4939-2815-6_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The agglutination assay is used to determine the ability of antibodies to recognize parasite variant antigens on the surface of Plasmodium falciparum-infected erythrocytes. In this technique, infected erythrocytes are selectively labelled with a DNA-binding fluorescent dye and mixed with antibodies of interest to allow antibody-surface antigen binding. Recognition of surface antigens by the antibodies can result in the formation of agglutinates containing multiple parasite-infected erythrocytes. These can be viewed and quantified using a fluorescence microscope.
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Affiliation(s)
- Joshua Tan
- KEMRI-Wellcome Trust Research Programme, 230-80108, Kilifi, Kenya
- Centre for Tropical Medicine, Nuffield Department of Medicine, Oxford University, Oxford, OX3 7LJ, UK
| | - Peter C Bull
- KEMRI-Wellcome Trust Research Programme, 230-80108, Kilifi, Kenya.
- Centre for Tropical Medicine, Nuffield Department of Medicine, Oxford University, Oxford, OX3 7LJ, UK.
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16
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Hodgson SH, Juma E, Salim A, Magiri C, Kimani D, Njenga D, Muia A, Cole AO, Ogwang C, Awuondo K, Lowe B, Munene M, Billingsley PF, James ER, Gunasekera A, Sim BKL, Njuguna P, Rampling TW, Richman A, Abebe Y, Kamuyu G, Muthui M, Elias SC, Molyneux S, Gerry S, Macharia A, Williams TN, Bull PC, Hill AVS, Osier FH, Draper SJ, Bejon P, Hoffman SL, Ogutu B, Marsh K. Evaluating controlled human malaria infection in Kenyan adults with varying degrees of prior exposure to Plasmodium falciparum using sporozoites administered by intramuscular injection. Front Microbiol 2014; 5:686. [PMID: 25566206 PMCID: PMC4264479 DOI: 10.3389/fmicb.2014.00686] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 11/14/2014] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Controlled human malaria infection (CHMI) studies are a vital tool to accelerate vaccine and drug development. As CHMI trials are performed in a controlled environment, they allow unprecedented, detailed evaluation of parasite growth dynamics (PGD) and immunological responses. However, CHMI studies have not been routinely performed in malaria-endemic countries or used to investigate mechanisms of naturally-acquired immunity (NAI) to Plasmodium falciparum. METHODS We conducted an open-label, randomized CHMI pilot-study using aseptic, cryopreserved P. falciparum sporozoites (PfSPZ Challenge) to evaluate safety, infectivity and PGD in Kenyan adults with low to moderate prior exposure to P. falciparum (Pan African Clinical Trial Registry: PACTR20121100033272). RESULTS All participants developed blood-stage infection confirmed by quantitative polymerase chain reaction (qPCR). However one volunteer (110) remained asymptomatic and blood-film negative until day 21 post-injection of PfSPZ Challenge. This volunteer had a reduced parasite multiplication rate (PMR) (1.3) in comparison to the other 27 volunteers (median 11.1). A significant correlation was seen between PMR and screening anti-schizont Enzyme Linked Immunosorbent Assays (ELISA) OD (p = 0.044, R = -0.384) but not when volunteer 110 was excluded from the analysis (p = 0.112, R = -0.313). CONCLUSIONS PfSPZ Challenge is safe and infectious in malaria-endemic populations and could be used to assess the efficacy of malaria vaccines and drugs in African populations. Whilst our findings are limited by sample size, our pilot study has demonstrated for the first time that NAI may impact on PMR post-CHMI in a detectable fashion, an important finding that should be evaluated in further CHMI studies.
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Affiliation(s)
| | - Elizabeth Juma
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya ; Centre for Research in Therapeutic Sciences, Strathmore University Nairobi, Kenya
| | - Amina Salim
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Charles Magiri
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya
| | - Domtila Kimani
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Daniel Njenga
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya
| | - Alfred Muia
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya
| | - Andrew O Cole
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya ; Centre for Research in Therapeutic Sciences, Strathmore University Nairobi, Kenya
| | - Caroline Ogwang
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Ken Awuondo
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Brett Lowe
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Marianne Munene
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | | | | | | | | | - Patricia Njuguna
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | | | | | | | - Gathoni Kamuyu
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Michelle Muthui
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Sean C Elias
- The Jenner Institute, University of Oxford Oxford, UK
| | - Sassy Molyneux
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Stephen Gerry
- Centre for Statistics in Medicine, University of Oxford Oxford, UK
| | - Alex Macharia
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | - Thomas N Williams
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya ; Department of Medicine, Imperial College London London, UK
| | - Peter C Bull
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | | | - Faith H Osier
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | | | - Philip Bejon
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
| | | | - Bernhards Ogutu
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya ; Centre for Research in Therapeutic Sciences, Strathmore University Nairobi, Kenya
| | - Kevin Marsh
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute - Wellcome Trust Kilifi, Kenya
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17
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Abstract
The level of plasma soluble ICAM-1 (sICAM-1) has been associated with the pathogenesis of several diseases. Previously, a commercial antibody was reported not to recognize an ICAM-1 allele known as ICAM-1kilifi prevalent among African populations. However, that study was based on 19 samples from African Americans of whom 13 had the wild type allele, five heterozygotes and one homozygote. Here, we compare plasma sICAM-1 measures using three different commercial antibodies in samples from Kenyan children genotyped for ICAM-1kilifi allele. We show that two of these antibodies have some degree of deficiency in detecting the ICAM-1kilifi allele. Consideration of the antibody used to measure sICAM-1 is important as up to 30% of the populations in Africa harbour this allele.
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Affiliation(s)
- Abdirahman I. Abdi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Biochemistry and Chemistry, Pwani University, Kilifi, Kenya
- * E-mail:
| | | | - Esther Kiragu
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Peter C. Bull
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
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18
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Warimwe GM, Fegan G, Kiragu EW, Musyoki JN, Macharia AW, Marsh K, Williams TN, Bull PC. An assessment of the impact of host polymorphisms on Plasmodium falciparum var gene expression patterns among Kenyan children. BMC Infect Dis 2014; 14:524. [PMID: 25267261 PMCID: PMC4262213 DOI: 10.1186/1471-2334-14-524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 09/24/2014] [Indexed: 11/16/2022] Open
Abstract
Background Host genotype accounts for a component of the variability in susceptibility to childhood Plasmodium falciparum malaria. However, despite numerous examples of host polymorphisms associated with tolerance or resistance to infection, direct evidence for an impact of host genetic polymorphisms on the in vivo parasite population is difficult to obtain. Parasite molecules whose expression is most likely to be associated with such adaptation are those that are directly involved in the host-parasite interaction. A prime candidate is the family of parasite var gene-encoded molecules on P. falciparum-infected erythrocytes, PfEMP1, which binds various host molecules and facilitates parasite sequestration in host tissues to avoid clearance by the spleen. Methods To assess the impact of host genotype on the infecting parasite population we used a published parasite var gene sequence dataset to compare var gene expression patterns between parasites from children with polymorphisms in molecules thought to interact with or modulate display of PfEMP1 on the infected erythrocyte surface: ABO blood group, haemoglobin S, alpha-thalassaemia, the T188G polymorphism of CD36 and the K29M polymorphism of ICAM1. Results Expression levels of ‘group A-like’ var genes, which encode a specific group of PfEMP1 variants previously associated with low host immunity and severe malaria, showed signs of elevation among children of blood group AB. No other host factor tested showed evidence for an association with var expression. Conclusions Our preliminary findings suggest that host ABO blood group may have a measurable impact on the infecting parasite population. This needs to be verified in larger studies. Electronic supplementary material The online version of this article (doi:10.1186/1471-2334-14-524) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- George M Warimwe
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
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19
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Abdi AI, Fegan G, Muthui M, Kiragu E, Musyoki JN, Opiyo M, Marsh K, Warimwe GM, Bull PC. Plasmodium falciparum antigenic variation: relationships between widespread endothelial activation, parasite PfEMP1 expression and severe malaria. BMC Infect Dis 2014; 14:170. [PMID: 24674301 PMCID: PMC3986854 DOI: 10.1186/1471-2334-14-170] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 03/19/2014] [Indexed: 12/01/2022] Open
Abstract
Background Plasmodium falciparum erythrocyte membrane protein 1(PfEMP1) is a family of variant surface antigens (VSA) that mediate the adhesion of parasite infected erythrocytes to capillary endothelial cells within host tissues. Opinion is divided over the role of PfEMP1 in the widespread endothelial activation associated with severe malaria. In a previous study we found evidence for differential associations between defined VSA subsets and specific syndromes of severe malaria: group A-like PfEMP1 expression and the “rosetting” phenotype were associated with impaired consciousness and respiratory distress, respectively. This study explores the involvement of widespread endothelial activation in these associations. Methods We used plasma angiopoietin-2 as a marker of widespread endothelial activation. Using logistic regression analysis, we explored the relationships between plasma angiopoietin-2 levels, parasite VSA expression and the two syndromes of severe malaria, impaired consciousness and respiratory distress. Results Plasma angiopoietin-2 was associated with both syndromes. The rosetting phenotype did not show an independent association with respiratory distress when adjusted for angiopoietin-2, consistent with a single pathogenic mechanism involving widespread endothelial activation. In contrast, group A-like PfEMP1 expression and angiopoietin-2 maintained independent associations with impaired consciousness when adjusted for each other. Conclusion The results are consistent with multiple pathogenic mechanisms leading to severe malaria and heterogeneity in the pathophysiology of impaired consciousness. The observed association between group A-like PfEMP1 and impaired consciousness does not appear to involve widespread endothelial activation.
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Affiliation(s)
- Abdirahman I Abdi
- KEMRI-Wellcome Trust Research Programme, P,O, Box 230-80108, Kilifi, Kenya.
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20
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Warimwe GM, Recker M, Kiragu EW, Buckee CO, Wambua J, Musyoki JN, Marsh K, Bull PC. Plasmodium falciparum var gene expression homogeneity as a marker of the host-parasite relationship under different levels of naturally acquired immunity to malaria. PLoS One 2013; 8:e70467. [PMID: 23922996 PMCID: PMC3726600 DOI: 10.1371/journal.pone.0070467] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 06/19/2013] [Indexed: 11/19/2022] Open
Abstract
Acquired immunity to Plasmodium falciparum infection causes a change from frequent, sometimes life-threatening, malaria in young children to asymptomatic, chronic infections in older children and adults. Little is known about how this transition occurs but antibodies to the extremely diverse PfEMP1 parasite antigens are thought to play a role. PfEMP1 is encoded by a family of 60 var genes that undergo clonal antigenic variation, potentially creating an antigenically heterogeneous infecting population of parasites within the host. Previous theoretical work suggests that antibodies to PfEMP1 may play a role in "orchestrating" their expression within infections leading to sequential, homogeneous expression of var genes, and prolonged infection chronicity. Here, using a cloning and sequencing approach we compare the var expression homogeneity (VEH) between isolates from children with asymptomatic and clinical infections. We show that asymptomatic infections have higher VEH than clinical infections and a broader host antibody response. We discuss this in relation to the potential role of host antibodies in promoting chronicity of infection and parasite survival through the low transmission season.
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Affiliation(s)
- George M. Warimwe
- Pathogen, Vector and Human Biology Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Mario Recker
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Esther W. Kiragu
- Pathogen, Vector and Human Biology Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Caroline O. Buckee
- Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Juliana Wambua
- Pathogen, Vector and Human Biology Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Jennifer N. Musyoki
- Pathogen, Vector and Human Biology Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kevin Marsh
- Pathogen, Vector and Human Biology Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Peter C. Bull
- Pathogen, Vector and Human Biology Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
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21
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Warimwe GM, Fegan G, Musyoki JN, Newton CRJC, Opiyo M, Githinji G, Andisi C, Menza F, Kitsao B, Marsh K, Bull PC. Prognostic indicators of life-threatening malaria are associated with distinct parasite variant antigen profiles. Sci Transl Med 2012; 4:129ra45. [PMID: 22496547 DOI: 10.1126/scitranslmed.3003247] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PfEMP1 is a family of cytoadhesive surface antigens expressed on erythrocytes infected with Plasmodium falciparum, the parasite that causes the most severe form of malaria. These surface antigens play a role in immune evasion and are thought to contribute to the pathogenesis of the malaria parasite. Previous studies have suggested a role for a specific subset of PfEMP1 called "group A" in severe malaria. To explore the role of group A PfEMP1 in disease, we measured the expression of the var genes that encode them in parasites from clinical isolates collected from children suffering from malaria. We also looked at the ability of these clinical isolates to induce rosetting of erythrocytes, which indicates a cytoadhesion phenotype that is thought to be important in pathogenesis. These two sets of data were correlated with the presence of two life-threatening manifestations of severe malaria in the children: impaired consciousness and respiratory distress. Using regression analysis, we show that marked rosetting was associated with respiratory distress, whereas elevated expression of group A-like var genes without elevated rosetting was associated with impaired consciousness. The results suggest that manifestations of malarial disease may reflect the distribution of cytoadhesion phenotypes expressed by the infecting parasite population.
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Affiliation(s)
- George M Warimwe
- Kenya Medical Research Institute-Wellcome Trust Research Programme, P. O. Box 230-80108 Kilifi, Kenya
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22
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Chan JA, Howell KB, Reiling L, Ataide R, Mackintosh CL, Fowkes FJI, Petter M, Chesson JM, Langer C, Warimwe GM, Duffy MF, Rogerson SJ, Bull PC, Cowman AF, Marsh K, Beeson JG. Targets of antibodies against Plasmodium falciparum-infected erythrocytes in malaria immunity. J Clin Invest 2012; 122:3227-38. [PMID: 22850879 DOI: 10.1172/jci62182] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 06/21/2012] [Indexed: 11/17/2022] Open
Abstract
Plasmodium falciparum is the major cause of malaria globally and is transmitted by mosquitoes. During parasitic development, P. falciparum-infected erythrocytes (P. falciparum-IEs) express multiple polymorphic proteins known as variant surface antigens (VSAs), including the P. falciparum erythrocyte membrane protein 1 (PfEMP1). VSA-specific antibodies are associated with protection from symptomatic and severe malaria. However, the importance of the different VSA targets of immunity to malaria remains unclear, which has impeded an understanding of malaria immunity and vaccine development. In this study, we developed assays using transgenic P. falciparum with modified PfEMP1 expression to quantify serum antibodies to VSAs among individuals exposed to malaria. We found that the majority of the human antibody response to the IE targets PfEMP1. Furthermore, our longitudinal studies showed that individuals with PfEMP1-specific antibodies had a significantly reduced risk of developing symptomatic malaria, whereas antibodies to other surface antigens were not associated with protective immunity. Using assays that measure antibody-mediated phagocytosis of IEs, an important mechanism in parasite clearance, we identified PfEMP1 as the major target of these functional antibodies. Taken together, these data demonstrate that PfEMP1 is a key target of humoral immunity. These findings advance our understanding of the targets and mediators of human immunity to malaria and have major implications for malaria vaccine development.
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Affiliation(s)
- Jo-Anne Chan
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
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23
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Ghumra A, Semblat JP, Ataide R, Kifude C, Adams Y, Claessens A, Anong DN, Bull PC, Fennell C, Arman M, Amambua-Ngwa A, Walther M, Conway DJ, Kassambara L, Doumbo OK, Raza A, Rowe JA. Induction of strain-transcending antibodies against Group A PfEMP1 surface antigens from virulent malaria parasites. PLoS Pathog 2012; 8:e1002665. [PMID: 22532802 PMCID: PMC3330128 DOI: 10.1371/journal.ppat.1002665] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Accepted: 03/08/2012] [Indexed: 12/22/2022] Open
Abstract
Sequence diversity in pathogen antigens is an obstacle to the development of interventions against many infectious diseases. In malaria caused by Plasmodium falciparum, the PfEMP1 family of variant surface antigens encoded by var genes are adhesion molecules that play a pivotal role in malaria pathogenesis and clinical disease. PfEMP1 is a major target of protective immunity, however, development of drugs or vaccines based on PfEMP1 is problematic due to extensive sequence diversity within the PfEMP1 family. Here we identified the PfEMP1 variants transcribed by P. falciparum strains selected for a virulence-associated adhesion phenotype (IgM-positive rosetting). The parasites transcribed a subset of Group A PfEMP1 variants characterised by an unusual PfEMP1 architecture and a distinct N-terminal domain (either DBLα1.5 or DBLα1.8 type). Antibodies raised in rabbits against the N-terminal domains showed functional activity (surface reactivity with live infected erythrocytes (IEs), rosette inhibition and induction of phagocytosis of IEs) down to low concentrations (<10 µg/ml of total IgG) against homologous parasites. Furthermore, the antibodies showed broad cross-reactivity against heterologous parasite strains with the same rosetting phenotype, including clinical isolates from four sub-Saharan African countries that showed surface reactivity with either DBLα1.5 antibodies (variant HB3var6) or DBLα1.8 antibodies (variant TM284var1). These data show that parasites with a virulence-associated adhesion phenotype share IE surface epitopes that can be targeted by strain-transcending antibodies to PfEMP1. The existence of shared surface epitopes amongst functionally similar disease-associated P. falciparum parasite isolates suggests that development of therapeutic interventions to prevent severe malaria is a realistic goal. Malaria remains one of the world's most deadly diseases. Life-threatening malaria is linked to a process called rosetting, in which malaria parasite-infected red blood cells bind to uninfected red cells to form aggregates that block blood flow in vital organs such as the brain. Current efforts to develop drugs or vaccines against rosetting are hindered by variation in the parasite rosette-mediating proteins, found on the surface of infected red cells. We studied these parasite-derived surface proteins and discovered that although they are variable, they share some common features. We raised antibodies against the rosette-mediating proteins, and found that they cross-reacted with multiple rosetting parasite strains from different countries around the world, including samples collected directly from African children with severe malaria. These findings provide new insights into malaria parasite interactions with human cells, and provide proof of principle that variable parasite molecules from virulent malaria parasites can induce strain-transcending antibodies. Hence, this work provides the foundation for the development of new therapies to treat or prevent life-threatening malaria.
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Affiliation(s)
- Ashfaq Ghumra
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jean-Philippe Semblat
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Ricardo Ataide
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Carolyne Kifude
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Yvonne Adams
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Antoine Claessens
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Damian N. Anong
- Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Peter C. Bull
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Clare Fennell
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Monica Arman
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Michael Walther
- Medical Research Council Laboratories, Fajara, Banjul, The Gambia
| | - David J. Conway
- Medical Research Council Laboratories, Fajara, Banjul, The Gambia
| | - Lalla Kassambara
- Malaria Research and Training Centre, University of Bamako, Bamako, Mali
| | - Ogobara K. Doumbo
- Malaria Research and Training Centre, University of Bamako, Bamako, Mali
| | - Ahmed Raza
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - J. Alexandra Rowe
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Gitau EN, Tuju J, Stevenson L, Kimani E, Karanja H, Marsh K, Bull PC, Urban BC. T-cell responses to the DBLα-tag, a short semi-conserved region of the Plasmodium falciparum membrane erythrocyte protein 1. PLoS One 2012; 7:e30095. [PMID: 22272280 PMCID: PMC3260199 DOI: 10.1371/journal.pone.0030095] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 12/09/2011] [Indexed: 11/25/2022] Open
Abstract
The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a variant surface antigen expressed on mature forms of infected erythrocytes. It is considered an important target of naturally acquired immunity. Despite its extreme sequence heterogeneity, variants of PfEMP1 can be stratified into distinct groups. Group A PfEMP1 have been independently associated with low host immunity and severe disease in several studies and are now of potential interest as vaccine candidates. Although antigen-specific antibodies are considered the main effector mechanism in immunity to malaria, the induction of efficient and long-lasting antibody responses requires CD4+ T-cell help. To date, very little is known about CD4+ T-cell responses to PfEMP1 expressed on clinical isolates. The DBLα-tag is a small region from the DBLα-domain of PfEMP1 that can be amplified with universal primers and is accessible in clinical parasite isolates. We identified the dominant expressed PfEMP1 in 41 individual clinical parasite isolates and expressed the corresponding DBLα-tag as recombinant antigen. Individual DBLα-tags were then used to activate CD4+ T-cells from acute and convalescent blood samples in children who were infected with the respective clinical parasite isolate. Here we show that CD4+ T-cell responses to the homologous DBLα-tag were induced in almost all children during acute malaria and maintained in some for 4 months. Children infected with parasites that dominantly expressed group A-like PfEMP1 were more likely to maintain antigen-specific IFNγ-producing CD4+ T-cells than children infected with parasites dominantly expressing other PfEMP1. These results suggest that group A-like PfEMP1 may induce long-lasting effector memory T-cells that might be able to provide rapid help to variant-specific B cells. Furthermore, a number of children induced CD4+ T-cell responses to heterologous DBLα-tags, suggesting that CD4+ T-cells may recognise shared epitopes between several DBLα-tags.
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Affiliation(s)
- Evelyn N. Gitau
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - James Tuju
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
| | - Liz Stevenson
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
| | - Eva Kimani
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
| | - Henry Karanja
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
| | - Kevin Marsh
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
- Centre for Tropical Medicine, Nuffield Department of Internal Medicine, Oxford University, Oxford, United Kingdom
| | - Peter C. Bull
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
- Centre for Tropical Medicine, Nuffield Department of Internal Medicine, Oxford University, Oxford, United Kingdom
| | - Britta C. Urban
- KEMRI-Wellcome Trust Collaborative Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
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Bejon P, Turner L, Lavstsen T, Cham G, Olotu A, Drakeley CJ, Lievens M, Vekemans J, Savarese B, Lusingu J, von Seidlein L, Bull PC, Marsh K, Theander TG. Serological evidence of discrete spatial clusters of Plasmodium falciparum parasites. PLoS One 2011; 6:e21711. [PMID: 21747921 PMCID: PMC3126844 DOI: 10.1371/journal.pone.0021711] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 06/06/2011] [Indexed: 11/19/2022] Open
Abstract
Background Malaria transmission may be considered to be homogenous with well-mixed parasite populations (as in the classic Ross/Macdonald models). Marked fine-scale heterogeneity of transmission has been observed in the field (i.e., over a few kilometres), but there are relatively few data on the degree of mixing. Since the Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) is highly polymorphic, the host's serological responses may be used to infer exposure to parasite sub-populations. Methods and Findings We measured the antibody responses to 46 individual PfEMP1 domains at four time points among 450 children in Kenya, and identified distinct spatial clusters of antibody responses to individual domains. 35 domains showed strongly significant sero-clusters at p = 0.001. Individuals within the high transmission hotspot showed the greatest diversity of anti-PfEMP1 responses. Individuals outside the hotspot had a less diverse range of responses, even if as individuals they were at relatively intense exposure. Conclusions We infer that antigenically distinct sub-populations of parasites exist on a fine spatial scale in a study area of rural Kenya. Further studies should examine antigenic variation over longer periods of time and in different study areas.
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Affiliation(s)
- Philip Bejon
- Centre for Geographic Medicine Research, Kenya Medical Research Institute/Wellcome Trust Programme, Coast, Kilifi, Kenya.
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Osier FHA, Murungi LM, Fegan G, Tuju J, Tetteh KK, Bull PC, Conway DJ, Marsh K. Allele-specific antibodies to Plasmodium falciparum merozoite surface protein-2 and protection against clinical malaria. Parasite Immunol 2010; 32:193-201. [PMID: 20398182 PMCID: PMC2847195 DOI: 10.1111/j.1365-3024.2009.01178.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
IgG and IgG3 antibodies to merozoite surface protein-2 (MSP-2) of Plasmodium falciparum have been associated with protection from clinical malaria in independent studies. We determined whether this protection was allele-specific by testing whether children who developed clinical malaria lacked IgG/IgG3 antibodies specific to the dominant msp2 parasite genotypes detected during clinical episodes. We analysed pre-existing IgG and IgG1/IgG3 antibodies to antigens representing the major dimorphic types of MSP-2 by ELISA. We used quantitative real-time PCR to determine the dominant msp2 alleles in parasites detected in clinical episodes. Over half (55%, 80/146) of infections contained both allelic types. Single or dominant IC1- and FC27-like alleles were detected in 46% and 42% of infections respectively, and both types were equally dominant in 12%. High levels of IgG/IgG3 antibodies to the FC27-like antigen were not significantly associated with a lower likelihood of clinical episodes caused by parasites bearing FC27-like compared to IC1-like alleles, and vice versa for IgG/IgG3 antibodies to the IC1-like antigen. These findings were supported by competition ELISAs which demonstrated the presence of IgG antibodies to allele-specific epitopes within both antigens. Thus, even for this well-studied antigen, the importance of an allele-specific component of naturally acquired protective immunity to malaria remains to be confirmed.
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Affiliation(s)
- F H A Osier
- KEMRI-Centre for Geographic Medicine Research, Coast, Kilifi, Kenya.
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Kinyanjui SM, Bejon P, Osier FH, Bull PC, Marsh K. What you see is not what you get: implications of the brevity of antibody responses to malaria antigens and transmission heterogeneity in longitudinal studies of malaria immunity. Malar J 2009; 8:242. [PMID: 19860926 PMCID: PMC2773787 DOI: 10.1186/1475-2875-8-242] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 10/28/2009] [Indexed: 11/18/2022] Open
Abstract
Background A major handicap in developing a malaria vaccine is the difficulty in pinpointing the immune responses that protect against malaria. The protective efficacy of natural or vaccine-induced immune responses against malaria is normally assessed by relating the level of the responses in an individual at the beginning of a follow-up period and the individual's experience of malaria infection or disease during the follow-up. This approach has identified a number of important responses against malaria, but their protective efficacies vary considerably between studies. Hypothesis It is likely that apart from differences in study methodologies, differences in exposure among study subjects within each study and brevity of antibody responses to malaria antigen are important sources of the variation in protective efficacy of anti-malaria immune responses mentioned above. Since malaria immunity is not complete, anyone in an area of stable malaria transmission who does not become asymptomatically or symptomatically infected during follow-up subsequent to treatment is most likely unexposed rather than immune. Testing the hypothesis It is proposed that individuals involved in a longitudinal study of malaria immunity should be treated for malaria prior to the start of the study and only those who present with at least an asymptomatic infection during the follow-up should be included in the analysis. In addition, it is proposed that more closely repeated serological survey should be carried out during follow-up in order to get a better picture of an individual's serological status. Implications of the hypothesis Failure to distinguish between individuals who do not get a clinical episode during follow-up because they were unexposed and those who are genuinely immune undermines our ability to assign a protective role to immune responses against malaria. The brevity of antibodies responses makes it difficult to assign the true serological status of an individual at any given time, i.e. those positive at a survey may be negative by the time they encounter the next infection.
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Affiliation(s)
- Samson M Kinyanjui
- Kenyan Medical Research Institute (KEMRI), Centre for Geographic Medicine Research (Coast), PO Box 230, Kilifi 80108, Kenya.
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Abstract
The malaria parasite Plasmodium falciparum is characterized by high levels of genetic diversity at antigenic loci involved in virulence and immune evasion. Knowledge of the population structure and dynamics of these genes is important for designing control programmes and understanding the acquisition of immunity to malaria; however, high rates of homologous and non-homologous recombination as well as complex patterns of expression within hosts have hindered attempts to elucidate these structures experimentally. Here, we analyse serological data from Kenya using a novel network technique to deconstruct the relationships between patients' immune responses to different parasite isolates. We show that particular population structures and expression patterns produce distinctive signatures within serological networks of parasite recognition, which can be used to discriminate between competing hypotheses regarding the organization of these genes. Our analysis suggests that different levels of immune selection occur within different groups of the same multigene family leading to mixed population structures.
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Affiliation(s)
- Caroline O Buckee
- Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford OX1 3PS, UK.
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Bull PC, Buckee CO, Kyes S, Kortok MM, Thathy V, Guyah B, Stoute JA, Newbold CI, Marsh K. Plasmodium falciparum antigenic variation. Mapping mosaic var gene sequences onto a network of shared, highly polymorphic sequence blocks. Mol Microbiol 2008; 68:1519-34. [PMID: 18433451 PMCID: PMC2440560 DOI: 10.1111/j.1365-2958.2008.06248.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a potentially important family of immune targets, encoded by an extremely diverse gene family called var. Understanding of the genetic organization of var genes is hampered by sequence mosaicism that results from a long history of non-homologous recombination. Here we have used software designed to analyse social networks to visualize the relationships between large collections of short var sequences tags sampled from clinical parasite isolates. In this approach, two sequences are connected if they share one or more highly polymorphic sequence blocks. The results show that the majority of analysed sequences including several var-like sequences from the chimpanzee parasite Plasmodium reichenowi can be either directly or indirectly linked together in a single unbroken network. However, the network is highly structured and contains putative subgroups of recombining sequences. The major subgroup contains the previously described group A var genes, previously proposed to be genetically distinct. Another subgroup contains sequences found to be associated with rosetting, a parasite virulence phenotype. The mosaic structure of the sequences and their division into subgroups may reflect the conflicting problems of maximizing antigenic diversity and minimizing epitope sharing between variants while maintaining their host cell binding functions.
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Affiliation(s)
- Peter C Bull
- Kenya Medical Research Institute, Centre for Geographic Medicine Research, Coast, Kilifi, Kenya.
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30
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Verra F, Simpore J, Warimwe GM, Tetteh KK, Howard T, Osier FHA, Bancone G, Avellino P, Blot I, Fegan G, Bull PC, Williams TN, Conway DJ, Marsh K, Modiano D. Haemoglobin C and S role in acquired immunity against Plasmodium falciparum malaria. PLoS One 2007; 2:e978. [PMID: 17912355 PMCID: PMC1991593 DOI: 10.1371/journal.pone.0000978] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Accepted: 09/13/2007] [Indexed: 11/19/2022] Open
Abstract
A recently proposed mechanism of protection for haemoglobin C (HbC; β6Glu→Lys) links an abnormal display of PfEMP1, an antigen involved in malaria pathogenesis, on the surface of HbC infected erythrocytes together with the observation of reduced cytoadhesion of parasitized erythrocytes and impaired rosetting in vitro. We investigated the impact of this hypothesis on the development of acquired immunity against Plasmodium falciparum variant surface antigens (VSA) encoding PfEMP1 in HbC in comparison with HbA and HbS carriers of Burkina Faso. We measured: i) total IgG against a single VSA, A4U, and against a panel of VSA from severe malaria cases in human sera from urban and rural areas of Burkina Faso of different haemoglobin genotypes (CC, AC, AS, SC, SS); ii) total IgG against recombinant proteins of P. falciparum asexual sporozoite, blood stage antigens, and parasite schizont extract; iii) total IgG against tetanus toxoid. Results showed that the reported abnormal cell-surface display of PfEMP1 on HbC infected erythrocytes observed in vitro is not associated to lower anti- PfEMP1 response in vivo. Higher immune response against the VSA panel and malaria antigens were observed in all adaptive genotypes containing at least one allelic variant HbC or HbS in the low transmission urban area whereas no differences were detected in the high transmission rural area. In both contexts the response against tetanus toxoid was not influenced by the β-globin genotype. These findings suggest that both HbC and HbS affect the early development of naturally acquired immunity against malaria. The enhanced immune reactivity in both HbC and HbS carriers supports the hypothesis that the protection against malaria of these adaptive genotypes might be at least partially mediated by acquired immunity against malaria.
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Affiliation(s)
- Federica Verra
- Dipartimento di Scienze di Sanità Pubblica, Sezione di Parassitologia, University of Rome-La Sapienza, Rome, Italy.
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Bull PC, Kyes S, Buckee CO, Montgomery J, Kortok MM, Newbold CI, Marsh K. An approach to classifying sequence tags sampled from Plasmodium falciparum var genes. Mol Biochem Parasitol 2007; 154:98-102. [PMID: 17467073 PMCID: PMC1906845 DOI: 10.1016/j.molbiopara.2007.03.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 03/16/2007] [Accepted: 03/16/2007] [Indexed: 11/25/2022]
Affiliation(s)
- Peter C Bull
- Kenya Medical Research Institute Centre for Geographic Medicine Research, Coast, Kilifi, Kenya.
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Kyriacou HM, Steen KE, Raza A, Arman M, Warimwe G, Bull PC, Havlik I, Rowe JA. In vitro inhibition of Plasmodium falciparum rosette formation by Curdlan sulfate. Antimicrob Agents Chemother 2007; 51:1321-6. [PMID: 17283200 PMCID: PMC1855515 DOI: 10.1128/aac.01216-06] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spontaneous binding of infected erythrocytes to uninfected erythrocytes to form rosettes is a property of some strains of Plasmodium falciparum that is linked to severe complications of malaria. Curdlan sulfate (CRDS) is a sulfated glycoconjugate compound that is chemically similar to known rosette-inhibiting drugs such as heparin. CRDS has previously been shown to have antimalarial activity in vitro and is safe for clinical use. Here we show that CRDS at therapeutic levels (10 to 100 microg/ml) significantly reduces rosette formation in vitro in seven P. falciparum laboratory strains and in a group of 18 African clinical isolates. The strong ability to inhibit rosetting suggests that CRDS has the potential to reduce the severe complications and mortality rates from P. falciparum malaria among African children. Our data support further clinical trials of CRDS.
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Affiliation(s)
- Helen M Kyriacou
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
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Urban BC, Cordery D, Shafi MJ, Bull PC, Newbold CI, Williams TN, Marsh K. The frequency of BDCA3-positive dendritic cells is increased in the peripheral circulation of Kenyan children with severe malaria. Infect Immun 2006; 74:6700-6. [PMID: 17000725 PMCID: PMC1698077 DOI: 10.1128/iai.00861-06] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ability of Plasmodium falciparum-infected erythrocytes to adhere to host endothelial cells via receptor molecules such as ICAM-1 and CD36 is considered a hallmark for the development of severe malaria syndromes. These molecules are also expressed on leukocytes such as dendritic cells. Dendritic cells are antigen-presenting cells that are crucial for the initiation of adaptive immune responses. In many human diseases, their frequency and function is perturbed. We analyzed the frequency of peripheral blood dendritic cell subsets and the plasma concentrations of interleukin-10 (IL-10) and IL-12 in Kenyan children with severe malaria and during convalescence and related these parameters to the adhesion phenotype of the acute parasite isolates. The frequency of CD1c(+) dendritic cells in children with acute malaria was comparable to that in healthy controls, but the frequency of BDCA3(+) dendritic cells was significantly increased. Analysis of the adhesion phenotypes of parasite isolates revealed that adhesion to ICAM-1 was associated with the frequency of peripheral blood CD1c(+) dendritic cells, whereas the adhesion of infected erythrocytes to CD36 correlated with high concentrations of IL-10 and low concentrations of IL-12 in plasma.
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Affiliation(s)
- Britta C Urban
- Centre for Clinical Vaccinology and Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Churchill Hospital, Old Road, Oxford OX3 7LJ, United Kingdom.
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Abstract
Immunity to malaria develops slowly with protection against the parasite lagging behind protection against disease symptoms. The data on the longevity of protective immune responses are sparse. However, studies of antibody responses associated with protection reveal that they consist of a short- and a long-lived component. Compared with the antibody levels observed in other infection and immunization systems, the levels of the short-lived antibody compartment drop below the detectable threshold with unusual rapidity. The prevalence of long-lived antibodies is comparable to that seen after bacterial and protozoan infections. There is even less available data concerning T cell longevity in malaria infection, but what there is seems to indicate that T cell memory is short in the absence of persistent antigen. In general, the degree and duration of parasite persistence represent a major factor determining how immune response longevity and protection correlate. The predilection for short-lived immune responses in malaria infection could be caused by a number of mechanisms resulting from the interplay of normal regulatory mechanisms of the immune system and immune evasion by the parasite. In conclusion, it appears that the parasite-host relationship has developed to favor some short-lived responses, which allow the host to survive while allowing the parasite to persist. Anti-malarial immune responses present a complex picture, and many aspects of regulation and longevity of the response require further research.
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Affiliation(s)
- A H Achtman
- Molecular Tumor Genetics and Immunogenetics, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.
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Bull PC, Berriman M, Kyes S, Quail MA, Hall N, Kortok MM, Marsh K, Newbold CI. Plasmodium falciparum variant surface antigen expression patterns during malaria. PLoS Pathog 2005; 1:e26. [PMID: 16304608 PMCID: PMC1287908 DOI: 10.1371/journal.ppat.0010026] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Accepted: 10/11/2005] [Indexed: 11/23/2022] Open
Abstract
The variant surface antigens expressed on Plasmodium falciparum–infected erythrocytes are potentially important targets of immunity to malaria and are encoded, at least in part, by a family of var genes, about 60 of which are present within every parasite genome. Here we use semi-conserved regions within short var gene sequence “tags” to make direct comparisons of var gene expression in 12 clinical parasite isolates from Kenyan children. A total of 1,746 var clones were sequenced from genomic and cDNA and assigned to one of six sequence groups using specific sequence features. The results show the following. (1) The relative numbers of genomic clones falling in each of the sequence groups was similar between parasite isolates and corresponded well with the numbers of genes found in the genome of a single, fully sequenced parasite isolate. In contrast, the relative numbers of cDNA clones falling in each group varied considerably between isolates. (2) Expression of sequences belonging to a relatively conserved group was negatively associated with the repertoire of variant surface antigen antibodies carried by the infected child at the time of disease, whereas expression of sequences belonging to another group was associated with the parasite “rosetting” phenotype, a well established virulence determinant. Our results suggest that information on the state of the host–parasite relationship in vivo can be provided by measurements of the differential expression of different var groups, and need only be defined by short stretches of sequence data. Hope that it will be possible to develop a malaria vaccine is supported by the fact that individuals who have grown up in malaria endemic regions learn to carry malarial infections without suffering disease. Surprisingly little is still known about how this immunity develops. Much current research focuses on how the host develops immune responses to parasite antigens that are exposed to the host immune system. A major family of such antigens are inserted into the surface of parasite-infected erythrocytes, where they undergo antigenic switching to evade a developing antibody response. These proteins are encoded by a family of approximately 60 var genes, variants of which are present in every parasite genome. The extreme diversity of the var genes has prevented meaningful comparison of their expression in clinical isolates. However, the authors of this paper show that var genes can be placed in groups that have a similar representation in the genomes of all parasites that the authors collected from Kenyan children. Having demonstrated an underlying similarity at the genomic level, the authors show that the var expression patterns vary markedly between different patients. The expression levels of specific groups of var genes was associated with poorly developed antibody responses in the children and a well-established parasite virulence phenotype. The study provides tools for exploring how host and parasite adapt to one another as immunity develops.
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Affiliation(s)
- Peter C Bull
- Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom.
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Bull PC, Pain A, Ndungu FM, Kinyanjui SM, Roberts DJ, Newbold CI, Marsh K. Plasmodium falciparum antigenic variation: relationships between in vivo selection, acquired antibody response, and disease severity. J Infect Dis 2005; 192:1119-26. [PMID: 16107968 DOI: 10.1086/432761] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Accepted: 04/19/2005] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Variant surface antigens (VSA) on Plasmodium falciparum-infected erythrocytes are potentially important targets of immunity to malaria. We previously identified a VSA phenotype--VSA with a high frequency of antibody recognition (VSA(FoRH))--that is associated with young host age and severe malaria. We hypothesized that VSA(FoRH) are positively selected by host molecules such as intercellular adhesion molecule 1 (ICAM1) and CD36 and dominate in the absence of an effective immune response. Here, we assessed, in 115 Kenyan children, the potential role played by in vivo selection pressures in either favoring or selecting against VSA(FoRH) among parasites that cause malaria. METHODS We tested for associations between VSA(FoRH) and (1) the repertoire of VSA antibodies carried by children at the time of acute malaria and (2) polymorphisms in ICAM1 (K29M) and CD36 (T188G) that could potentially reduce the positive selection of VSA(FoRH). RESULTS An expected negative association between VSA antibody repertoire and VSA(FoRH) was observed in children with nonsevere malaria. However, this association did not extend to children with severe malaria, many of whom apparently had well-developed VSA antibody responses despite being infected by parasites expressing VSA(FoRH). There was no evidence for involvement of CD36 or ICAM1 in positive selection of VSA(FoRH). On the contrary, a weak positive association between carriage of the CD36 (T188G) allele and VSA(FoRH) was observed in children with severe malaria. CONCLUSION The association between the VSA(FoRH) parasite phenotype and severe malaria cannot be explained simply in terms of the total repertoire of VSA antibodies carried at the time of acute disease.
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Affiliation(s)
- Peter C Bull
- Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom.
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Kinyanjui SM, Mwangi T, Bull PC, Newbold CI, Marsh K. Protection against Clinical Malaria by Heterologous Immunoglobulin G Antibodies against Malaria‐Infected Erythrocyte Variant Surface Antigens Requires Interaction with Asymptomatic Infections. J Infect Dis 2004; 190:1527-33. [PMID: 15478055 DOI: 10.1086/424675] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2003] [Accepted: 05/18/2004] [Indexed: 11/03/2022] Open
Abstract
Erythrocytes infected with mature stages of Plasmodium falciparum express variant surface antigens (VSAs) of parasite origin, including P. falciparum erythrocyte membrane protein 1. Anti-VSA antibodies protect against clinical malaria caused by parasites bearing VSAs to which they are specific (homologous), but their role in protecting against heterologous infection is unclear. Here, we report that, among 256 Kenyan children involved in a 1-year active case surveillance study, asymptomatic parasitemia was associated with an enlarged repertoire of anti-VSA immunoglobulin G (IgG) antibodies specific to apparently heterologous parasite isolates, as measured by flow cytometry. Together, asymptomatic infection and anti-VSA IgG were associated with reduced odds of experiencing an episode of clinical malaria during follow-up, whereas, independently, they were associated with increased susceptibility. These results support previous findings and underline the importance of considering the parasitological status of study participants when examining the role that immune responses to VSAs and other malaria antigens play.
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Affiliation(s)
- Samson M Kinyanjui
- Kenya Medical Research Institute Centre for Geographic Medicine Research Coast, Kilifi, Kenya.
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Kinyanjui SM, Howard T, Williams TN, Bull PC, Newbold CI, Marsh K. The use of cryopreserved mature trophozoites in assessing antibody recognition of variant surface antigens of Plasmodium falciparum-infected erythrocytes. J Immunol Methods 2004; 288:9-18. [PMID: 15183081 DOI: 10.1016/j.jim.2004.01.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2003] [Revised: 12/12/2003] [Accepted: 01/05/2004] [Indexed: 11/29/2022]
Abstract
Mature stages of Plasmodium falciparum insert variant antigens (VSA) into the surface of infected erythrocytes, and antibodies against such antigen provide variant-specific protection against malaria. Because mature P. falciparum trophozoites normally sequester away from the peripheral circulation, parasites for anti-VSA antibody studies are obtained from patients as ring trophozoites, cryopreserved, and cultured to maturity when required. However, this process is associated with problems of poor recovery from cryopreservation, growth failure and variations in time different isolates take to mature after recovery. We therefore assessed the use of cryopreserved mature trophozoites in anti-VSA assays. Cryopreservation of parasites did not alter their anti-VSA antibody reactivity phenotype as determined by agglutination assays or flow cytometry. We have therefore demonstrated that cryopreserved mature trophozoites are suitable for use in anti-VSA antibody assays. The use of cryopreserved mature trophozoites could help to circumvent the problems associated with recovery of cryopreserved ring trophozoites.
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Affiliation(s)
- Samson M Kinyanjui
- Kenya Medical Research Institute, Centre for Geographic Medicine Research Coast, P.O. Box 230, Kilifi, Kenya.
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Recker M, Nee S, Bull PC, Kinyanjui S, Marsh K, Newbold C, Gupta S. Transient cross-reactive immune responses can orchestrate antigenic variation in malaria. Nature 2004; 429:555-8. [PMID: 15175751 DOI: 10.1038/nature02486] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2003] [Accepted: 03/09/2004] [Indexed: 11/09/2022]
Abstract
The malaria parasite Plasmodium falciparum has evolved to prolong its duration of infection by antigenic variation of a major immune target on the surface of the infected red blood cell. This immune evasion strategy depends on the sequential, rather than simultaneous, appearance of immunologically distinct variants. Although the molecular mechanisms by which a single organism switches between variants are known in part, it remains unclear how an entire population of parasites within the host can synchronize expression to avoid rapidly exhausting the variant repertoire. Here we show that short-lived, partially cross-reactive immune responses to parasite-infected erythrocyte surface antigens can produce a cascade of sequentially dominant antigenic variants, each of which is the most immunologically distinct from its preceding types. This model reconciles several previously unexplained and apparently conflicting epidemiological observations by demonstrating that individuals with stronger cross-reactive immune responses can, paradoxically, be more likely to sustain chronic infections. Antigenic variation has always been seen as an adaptation of the parasite to evade host defence: we show that the coordination necessary for the success of this strategy might be provided by the host.
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Affiliation(s)
- Mario Recker
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
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Bull PC, Lowe BS, Kaleli N, Njuga F, Kortok M, Ross A, Ndungu F, Snow RW, Marsh K. Plasmodium falciparum infections are associated with agglutinating antibodies to parasite-infected erythrocyte surface antigens among healthy Kenyan children. J Infect Dis 2002; 185:1688-91. [PMID: 12023781 DOI: 10.1086/340420] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2001] [Revised: 01/24/2002] [Indexed: 11/03/2022] Open
Abstract
Antibodies to the highly diverse variant surface antigens (VSAs) expressed on Plasmodium falciparum-infected erythrocytes are thought to play a role in the development of naturally acquired immunity to malaria. It has been suggested that children gradually acquire immunity through the piecemeal acquisition of antibodies to a large number of VSAs over several years of exposure. However, in a cross-sectional survey of Kenyan children before the malaria-transmission season, the proportion of children with antibodies recognizing randomly sampled VSAs was found to be strikingly higher among children with microscopically detectable P. falciparum infection, compared with those without detectable infection. We suggest that parasitization status may be an important consideration in longitudinal assessments of the protective role of some anti-parasite immune responses and support this suggestion with data from a prospective study of VSA antibodies in a group of children who subsequently had severe malaria.
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Affiliation(s)
- Peter C Bull
- Kenya Medical Research Insitute (KEMRI) Centre for Geographic Medicine Research, Coast, Kilifi, Kenya.
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Ndungu FM, Bull PC, Ross A, Lowe BS, Kabiru E, Marsh K. Naturally acquired immunoglobulin (Ig)G subclass antibodies to crude asexual Plasmodium falciparum lysates: evidence for association with protection for IgG1 and disease for IgG2. Parasite Immunol 2002; 24:77-82. [PMID: 11874562 DOI: 10.1046/j.0141-9838.2001.00440.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There is longstanding evidence for a role of immunoglobulin (Ig)G in protection against malarial disease and infection. IgG1 and IgG3 have been shown to be particularly efficient at associating with monocytes in potentially protective mechanisms (i.e. antibody-dependent cellular inhibition, opsonization and phagocytosis). Conversely, there is some evidence that IgG2 (and possibly IgG4) antibodies may be antagonistic to this protection. The protective effect of IgG subclass antibody activity present before the beginning of a malaria transmission season (preseason antibody levels) against severe malaria has not been tested in longitudinal studies. We measured IgG class and subclass antibody levels specific to crude Plasmodium falciparum lysates by enzyme linked immunosorbent assay in a case-control study of 76 children on the coast of Kenya. The mean optical density values for both IgG class and subclass antibodies were not significantly different between the children who developed severe malaria and those who remained healthy during an observation period of two malaria transmission seasons. However, elevated levels of IgG1 in relation to levels of IgG2 and IgG4 antibodies were associated with protection from severe malaria (P = 0.02). Conversely, elevated levels of IgG2 in relation to IgG1 and IgG3 antibodies were associated with a higher risk of developing severe malaria (P = 0.006).
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Affiliation(s)
- Francis M Ndungu
- Kenya Medical Research Institute Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
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Bull PC, Marsh K. The role of antibodies to Plasmodium falciparum-infected-erythrocyte surface antigens in naturally acquired immunity to malaria. Trends Microbiol 2002; 10:55-8. [PMID: 11827798 DOI: 10.1016/s0966-842x(01)02278-8] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plasmodium falciparum, the most virulent species of human malaria parasite, causes 1-3 million deaths per year. Because this parasite is susceptible to naturally acquired host immunity the main burden of diseases falls on young children. The mechanism of this immunity is still unclear. However, the parasite makes a considerable investment in the insertion of highly polymorphic antigens (parasite-infected-erythrocyte surface antigens, PIESA) on the infected erythrocyte surface, and these antigens are potentially important immune targets.
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Bull PC, Kortok M, Kai O, Ndungu F, Ross A, Lowe BS, Newbold CI, Marsh K. Plasmodium falciparum-infected erythrocytes: agglutination by diverse Kenyan plasma is associated with severe disease and young host age. J Infect Dis 2000; 182:252-9. [PMID: 10882604 DOI: 10.1086/315652] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2000] [Revised: 04/07/2000] [Indexed: 11/03/2022] Open
Abstract
The variant surface antigens (VSAs) of Plasmodium falciparum-infected red blood cells are potentially important targets of naturally acquired immunity to malaria. Natural infections induce agglutinating antibodies specific to the VSA variants expressed by the infecting parasites. Previously, when different parasite isolates were tested against a panel of heterologous plasma from Kenyan children, the proportion of plasma that agglutinated the parasites (the agglutination frequency [AF]) was highly variable among isolates, suggesting the existence of rare and prevalent variants. Here, the AF of 115 isolates from Kenyan children were compared. The results show that the AF of isolates causing severe malaria were significantly higher than those of isolates causing mild malaria; and AF decreased significantly with the increasing age of the infected child. We propose that parasites causing severe disease tend to express a subset of VSA variants that are preferentially associated with infections of children with low immunity.
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Affiliation(s)
- P C Bull
- Kenya Medical Research Institute, Centre for Geographic Medicine Research-Coast, Kilifi Unit, Kilifi, Kenya.
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Bull PC, Lowe BS, Kortok M, Marsh K. Antibody recognition of Plasmodium falciparum erythrocyte surface antigens in Kenya: evidence for rare and prevalent variants. Infect Immun 1999; 67:733-9. [PMID: 9916084 PMCID: PMC96380 DOI: 10.1128/iai.67.2.733-739.1999] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is the name given to a family of parasite proteins that are inserted into the infected erythrocyte surface. Studies using agglutination assays have shown previously that PfEMP1 epitopes are extremely diverse. In a study in Kenya, 21 parasite isolates, including nine from children with severe malaria, were tested for agglutination by 33 pairs of plasma, 21 of which were from the corresponding children. Each plasma pair consisted of a sample taken at the time of disease (acute) and one taken 3 weeks later (convalescent). In agreement with previous studies, infection was generally followed by the induction of antibodies specific to the homologous parasite isolate. In addition however, the results show that (i) some isolates were agglutinated very frequently by heterologous plasma; (ii) unexpectedly, these frequently agglutinated isolates tended to be from individuals with severe malaria; (iii) an inverse relationship existed between the agglutination frequency of each parasite isolate in heterologous plasma and the agglutinating antibody repertoire of the homologous child at the time of disease; and (iv) A 3-month-old child apparently still carrying maternal antibodies was infected by a rarely agglutinated isolate. This child's plasma agglutinated all isolates at the time of disease, apart from the homologous isolate. These results support the idea that preexisting anti-PfEMP1 antibodies can select the variants that are expressed during a new infection and may suggest the existence of a dominant subset of PfEMP1 variants.
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Affiliation(s)
- P C Bull
- Kenya Medical Research Institute CGMRC, Kilifi Unit, Kilifi, Kenya.
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Affiliation(s)
- B S Lowe
- Kenya Medical Research Institute, Clinical Research Centre, Kilifi Unit, Kenya
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Bull PC, Lowe BS, Kortok M, Molyneux CS, Newbold CI, Marsh K. Parasite antigens on the infected red cell surface are targets for naturally acquired immunity to malaria. Nat Med 1998; 4:358-60. [PMID: 9500614 PMCID: PMC3836255 DOI: 10.1038/nm0398-358] [Citation(s) in RCA: 473] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The feasibility of a malaria vaccine is supported by the fact that children in endemic areas develop naturally acquired immunity to disease. Development of disease immunity is characterized by a decrease in the frequency and severity of disease episodes over several years despite almost continuous infection, suggesting that immunity may develop through the acquisition of a repertoire of specific, protective antibodies directed against polymorphic target antigens. Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a potentially important family of target antigens, because these proteins are inserted into the red cell surface and are prominently exposed and because they are highly polymorphic and undergo clonal antigenic variation, a mechanism of immune evasion maintained by a large family of var genes. In a large prospective study of Kenyan children, we have used the fact that anti-PfEMP1 antibodies agglutinate infected erythrocytes in a variant-specific manner, to show that the PfEMP1 variants expressed during episodes of clinical malaria were less likely to be recognized by the corresponding child's own preexisting antibody response than by that of children of the same age from the same community. In contrast, a heterologous parasite isolate was just as likely to be recognized. The apparent selective pressure exerted by established anti-PfEMP1 antibodies on infecting parasites supports the idea that such responses provide variant-specific protection against disease.
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Affiliation(s)
- P C Bull
- Kenya Medical Research Institute CRC, Kilifi Unit.
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Abstract
ATP7B, the gene altered in Wilson disease (WD) patients, lies in a block of homology shared between human chromosome 13q14 and the central region of mouse chromosome 14. However, we have mapped the murine homologue of ATP7B (Atp7b) to mouse chromosome 8 by somatic cell hybrid analysis. Analysis of 80 interspecific backcross offspring was used to position Atp7b close to D8Mit3 and another ATPase locus, Atp4b, on mouse chromosome 8. ATP4B lies in 13q34 and is separated from ATP7B by several loci whose mouse homologues map to mouse chromosome 14. The assignment of Atp7b to mouse chromosome 8 identifies a previously unrecognized region of homology between this chromosome and human chromosome 13. This assignment suggests a possible location for the toxic milk mutation in the mouse, which has been proposed as a homologue of WD.
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Affiliation(s)
- V Reed
- MRC Radiobiology Unit, Chilton, Didcot, England
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Abstract
Little is known at the molecular level about the homeostatic control of heavy-metal concentrations in mammals. Recently, however, two human diseases that disrupt copper transport, Menkes disease and Wilson disease, were found to be caused by mutations in two closely related genes, MNK and WND, which encode proteins belonging to the P-type ATPase family of cation transporters. The MNK and WND proteins are unique in having at their amino termini six copies of a sequence that is remarkably similar to sequences previously found in bacterial heavy-metal-resistance proteins and in a P-type ATPase that appears to form part of a bacterial copper homeostatic system. These two human ATPases are the first putative heavy-metal transporters to be discovered in eukaryotes.
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Affiliation(s)
- P C Bull
- Hospital for Sick Children, Toronto, Ontario, Canada
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Thomas GR, Bull PC, Roberts EA, Walshe JM, Cox DW. Haplotype studies in Wilson disease. Am J Hum Genet 1994; 54:71-8. [PMID: 8279472 PMCID: PMC1918068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In 51 families with Wilson disease, we have studied DNA haplotypes of dinucleotide repeat polymorphisms (CA repeats) in the 13q14.3 region, to examine these markers for association with the Wilson disease gene (WND). In addition to a marker (D13S133) described elsewhere, we have developed three new highly polymorphic markers (D13S314, D13S315, and D13S316) close to the WND locus. We have examined the distribution of marker alleles at the loci studied and have found that D13S314, D13S133, and D13S316 each show nonrandom distribution on chromosomes carrying the WND mutation. We have studied haplotypes of these three markers and have found that there are highly significant differences between WND and normal haplotypes in northern European families. These findings have important implications for mutation detection and molecular diagnosis in families with Wilson disease.
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Affiliation(s)
- G R Thomas
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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Bull PC, Thomas GR, Rommens JM, Forbes JR, Cox DW. The Wilson disease gene is a putative copper transporting P-type ATPase similar to the Menkes gene. Nat Genet 1993; 5:327-37. [PMID: 8298639 DOI: 10.1038/ng1293-327] [Citation(s) in RCA: 1284] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Wilson disease (WD) is an autosomal recessive disorder of copper transport, resulting in copper accumulation and toxicity to the liver and brain. The gene (WD) has been mapped to chromosome 13 q14.3. On yeast artificial chromosomes from this region we have identified a sequence, similar to that coding for the proposed copper binding regions of the putative ATPase gene (MNK) defective in Menkes disease. We show that this sequence forms part of a P-type ATPase gene (referred to here as Wc1) that is very similar to MNK, with six putative metal binding regions similar to those found in prokaryotic heavy metal transporters. The gene, expressed in liver and kidney, lies within a 300 kb region likely to include the WD locus. Two WD patients were found to be homozygous for a seven base deletion within the coding region of Wc1. Wc1 is proposed as the gene for WD.
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Affiliation(s)
- P C Bull
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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