1
|
Walker IS, Rogerson SJ. Pathogenicity and virulence of malaria: Sticky problems and tricky solutions. Virulence 2023; 14:2150456. [PMID: 36419237 PMCID: PMC9815252 DOI: 10.1080/21505594.2022.2150456] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/25/2022] Open
Abstract
Infections with Plasmodium falciparum and Plasmodium vivax cause over 600,000 deaths each year, concentrated in Africa and in young children, but much of the world's population remain at risk of infection. In this article, we review the latest developments in the immunogenicity and pathogenesis of malaria, with a particular focus on P. falciparum, the leading malaria killer. Pathogenic factors include parasite-derived toxins and variant surface antigens on infected erythrocytes that mediate sequestration in the deep vasculature. Host response to parasite toxins and to variant antigens is an important determinant of disease severity. Understanding how parasites sequester, and how antibody to variant antigens could prevent sequestration, may lead to new approaches to treat and prevent disease. Difficulties in malaria diagnosis, drug resistance, and specific challenges of treating P. vivax pose challenges to malaria elimination, but vaccines and other preventive strategies may offer improved disease control.
Collapse
Affiliation(s)
- Isobel S Walker
- Department of Infectious Diseases, The University of Melbourne, The Doherty Institute, Melbourne, Australia
| | - Stephen J Rogerson
- Department of Infectious Diseases, The University of Melbourne, The Doherty Institute, Melbourne, Australia
| |
Collapse
|
2
|
Barua P, Duffy MF, Manning L, Laman M, Davis TME, Mueller I, Haghiri A, Simpson JA, Beeson JG, Rogerson SJ. Antibody to Plasmodium falciparum Variant Surface Antigens, var Gene Transcription, and ABO Blood Group in Children With Severe or Uncomplicated Malaria. J Infect Dis 2023; 228:1099-1107. [PMID: 37341543 PMCID: PMC10582907 DOI: 10.1093/infdis/jiad217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 06/08/2023] [Accepted: 06/20/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND Antibodies to variant surface antigens (VSAs) such as Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) may vary with malaria severity. The influence of ABO blood group on antibody development is not understood. METHODS Immunoglobulin G antibodies to VSAs in Papua New Guinean children with severe (n = 41) or uncomplicated (n = 30) malaria were measured by flow cytometry using homologous P falciparum isolates. Isolates were incubated with ABO-matched homologous and heterologous acute and convalescent plasma. RNA was used to assess var gene transcription. RESULTS Antibodies to homologous, but not heterologous, isolates were boosted in convalescence. The relationship between antibody and severity varied by blood group. Antibodies to VSAs were similar in severe and uncomplicated malaria at presentation, higher in severe than uncomplicated malaria in convalescence, and higher in children with blood group O than other children. Six var gene transcripts best distinguished severe from uncomplicated malaria, including UpsA and 2 CIDRα1 domains. CONCLUSIONS ABO blood group may influence antibody acquisition to VSAs and susceptibility to severe malaria. Children in Papua New Guinea showed little evidence of acquisition of cross-reactive antibodies following malaria. Var gene transcripts in Papua New Guinean children with severe malaria were similar to those reported from Africa.
Collapse
Affiliation(s)
- Priyanka Barua
- Department of Medicine, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne
| | - Michael F Duffy
- Department of Medicine, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, Bio21 Institute, University of Melbourne, Parkville, Victoria
| | | | - Moses Laman
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang
| | | | - Ivo Mueller
- Population Health and Immunity, Walter and Eliza Hall Institute, Parkville, Victoria, Australia
- Department of Parasites and Insect Vector, Institut Pasteur, Paris, France
| | - Ali Haghiri
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
| | - James G Beeson
- Malaria Immunity and Vaccines Laboratory, Burnet Institute, Melbourne
- Central Clinical School and Department of Microbiology, Monash University, Clayton
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Stephen J Rogerson
- Department of Medicine, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
3
|
Mueller I, Vantaux A, Karl S, Laman M, Witkowski B, Pepey A, Vinit R, White M, Barry A, Beeson JG, Robinson LJ. Asia-Pacific ICEMR: Understanding Malaria Transmission to Accelerate Malaria Elimination in the Asia Pacific Region. Am J Trop Med Hyg 2022; 107:131-137. [PMID: 36228917 PMCID: PMC9662229 DOI: 10.4269/ajtmh.21-1336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 07/06/2022] [Indexed: 01/31/2023] Open
Abstract
Gaining an in-depth understanding of malaria transmission requires integrated, multifaceted research approaches. The Asia-Pacific International Center of Excellence in Malaria Research (ICEMR) is applying specifically developed molecular and immunological assays, in-depth entomological assessments, and advanced statistical and mathematical modeling approaches to a rich series of longitudinal cohort and cross-sectional studies in Papua New Guinea and Cambodia. This is revealing both the essential contribution of forest-based transmission and the particular challenges posed by Plasmodium vivax to malaria elimination in Cambodia. In Papua New Guinea, these studies document the complex host-vector-parasite interactions that are underlying both the stunning reductions in malaria burden from 2006 to 2014 and the significant resurgence in transmission in 2016 to 2018. Here we describe the novel analytical, surveillance, molecular, and immunological tools that are being applied in our ongoing Asia-Pacific ICEMR research program.
Collapse
Affiliation(s)
- Ivo Mueller
- Population Health & Immunity Division, Walter + Eliza Hall Institutes, Melbourne, Australia;,University of Melbourne, Melbourne, Australia;,Address correspondence to Ivo Mueller, Population Health & Immunity Division, Walter + Eliza Hall Institutes, 1G Royal Parade, Parkville, Victoria, Australia 3052. E-mail:
| | | | - Stephan Karl
- Australian Institute of Tropical Health & Medicine, James Cook University, Cairns, Australia;,PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Moses Laman
- PNG Institute of Medical Research, Madang, Papua New Guinea
| | | | - Anais Pepey
- Institute Pasteur Cambodia, Phnom Penh, Cambodia
| | - Rebecca Vinit
- PNG Institute of Medical Research, Madang, Papua New Guinea
| | | | - Alyssa Barry
- Deakin University, Geelong, Australia;,Burnet Institute, Melbourne, Australia
| | - James G. Beeson
- University of Melbourne, Melbourne, Australia;,Burnet Institute, Melbourne, Australia;,Monash University, Victoria, Australia
| | - Leanne J. Robinson
- Population Health & Immunity Division, Walter + Eliza Hall Institutes, Melbourne, Australia;,PNG Institute of Medical Research, Madang, Papua New Guinea;,Burnet Institute, Melbourne, Australia;,Monash University, Victoria, Australia
| |
Collapse
|
4
|
Naturally Acquired Antibodies against Plasmodium falciparum: Friend or Foe? Pathogens 2021; 10:pathogens10070832. [PMID: 34357982 PMCID: PMC8308493 DOI: 10.3390/pathogens10070832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022] Open
Abstract
Antibodies are central to acquired immunity against malaria. Plasmodium falciparum elicits antibody responses against many of its protein components, but there is also formation of antibodies against different parts of the red blood cells, in which the parasites spend most of their time. In the absence of a decisive intervention such as a vaccine, people living in malaria endemic regions largely depend on naturally acquired antibodies for protection. However, these antibodies do not confer sterile immunity and the mechanisms of action are still unclear. Most studies have focused on the inhibitory effect of antibodies, but here, we review both the beneficial as well as the potentially harmful roles of naturally acquired antibodies, as well as autoantibodies formed in malaria. We discuss different studies that have sought to understand acquired antibody responses against P. falciparum antigens, and potential problems when different antibodies are combined, such as in naturally acquired immunity.
Collapse
|
5
|
Rathnayake D, Aitken EH, Rogerson SJ. Beyond Binding: The Outcomes of Antibody-Dependent Complement Activation in Human Malaria. Front Immunol 2021; 12:683404. [PMID: 34168652 PMCID: PMC8217965 DOI: 10.3389/fimmu.2021.683404] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 05/24/2021] [Indexed: 11/13/2022] Open
Abstract
Antibody immunity against malaria is effective but non-sterile. In addition to antibody-mediated inhibition, neutralisation or opsonisation of malaria parasites, antibody-mediated complement activation is also important in defense against infection. Antibodies form immune complexes with parasite-derived antigens that can activate the classical complement pathway. The complement system provides efficient surveillance for infection, and its activation leads to parasite lysis or parasite opsonisation for phagocytosis. The induction of complement-fixing antibodies contributes significantly to the development of protective immunity against clinical malaria. These complement-fixing antibodies can form immune complexes that are recognised by complement receptors on innate cells of the immune system. The efficient clearance of immune complexes is accompanied by complement receptor internalisation, abrogating the detrimental consequences of excess complement activation. Here, we review the mechanisms of activation of complement by alternative, classical, and lectin pathways in human malaria at different stages of the Plasmodium life cycle with special emphasis on how complement-fixing antibodies contribute to protective immunity. We briefly touch upon the action of anaphylatoxins, the assembly of membrane attack complex, and the possible reasons underlying the resistance of infected erythrocytes towards antibody-mediated complement lysis, relevant to their prolonged survival in the blood of the human host. We make suggestions for further research on effector functions of antibody-mediated complement activation that would guide future researchers in deploying complement-fixing antibodies in preventive or therapeutic strategies against malaria.
Collapse
Affiliation(s)
| | | | - Stephen J. Rogerson
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
6
|
Zhu W, Ling X, Shang W, Du Y, Liu J, Cao Y, Yang M, Zhu G, Cao J, Huang J. High value of rapid diagnostic tests to diagnose malaria within children: A systematic review and meta-analysis. J Glob Health 2020; 10:010411. [PMID: 32373330 PMCID: PMC7182354 DOI: 10.7189/jogh.10.010411] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Background Children aged under five years accounted for 61% of all malaria deaths worldwide in 2017, and quicker differential diagnosis of malaria fever is vital for them. Rapid diagnostic tests (RDTs) are strips to detect Plasmodium specific antigens promptly and are helpful in resource-limited areas. Thus, our aim is to assess the diagnostic accuracy of RDTs for malaria in children against the gold standard. Methods MEDLINE, Web of Science, EMBASE, Cochrane Library, the China National Knowledge Infrastructure, Wanfang, and Sinomed databases were systematically searched on August 23, 2019. Studies that compared RDTs with microscopy or polymerase chain reaction in malaria diagnoses for children were eligible. Relevant data were extracted. The quality of studies was evaluated using the revised Quality Assessment of Diagnostic Accuracy Studies instrument. Meta-analyses were carried out to calculate the pooled estimates and 95% confidence intervals of sensitivity and specificity. Results 51 articles were included. For diagnostic accuracy, the pooled estimates of the sensitivity and specificity of RDTs were 0.93 (95% confidence interval (CI) = 0.90, 0.95) and 0.93 (95% CI = 0.90, 0.96) respectively. Studies were highly heterogeneous, and subgroup analyses showed that the application of RDTs in high malaria transmission areas had higher sensitivity but lower specificity than those in low-to-moderate areas. Conclusions RDTs have high accuracy for malaria diagnosis in children, and this characteristic is more prominent in high transmission areas. As they also have the advantages of rapid-detection, are easy-to-use, and can be cost-effective, it is recommended that the wider usage of RDTs should be promoted, especially in resource-limited areas. Further research is required to assess their performance in WHO South-East Asia and Americas Region.
Collapse
Affiliation(s)
- Wenjun Zhu
- Key Lab of Health Technology Assessment, National Health Commission; School of Public Health, Fudan University, Shanghai, China
| | - XiaoXiao Ling
- Department of Statistical Science, University College London, London, UK
| | - Wenru Shang
- Key Lab of Health Technology Assessment, National Health Commission; School of Public Health, Fudan University, Shanghai, China
| | - Yanqiu Du
- Key Lab of Health Technology Assessment, National Health Commission; School of Public Health, Fudan University, Shanghai, China
| | - Jinyu Liu
- Key Lab of Health Technology Assessment, National Health Commission; School of Public Health, Fudan University, Shanghai, China
| | - Yuanyuan Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Mengmeng Yang
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China
| | - Guoding Zhu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China.,Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, China.,Public Health Research Center, Jiangnan University, Wuxi, Jiangsu, China
| | - Jun Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, China.,Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, China.,Public Health Research Center, Jiangnan University, Wuxi, Jiangsu, China
| | - Jiayan Huang
- Key Lab of Health Technology Assessment, National Health Commission; School of Public Health, Fudan University, Shanghai, China
| |
Collapse
|
7
|
Gonzales SJ, Reyes RA, Braddom AE, Batugedara G, Bol S, Bunnik EM. Naturally Acquired Humoral Immunity Against Plasmodium falciparum Malaria. Front Immunol 2020; 11:594653. [PMID: 33193447 PMCID: PMC7658415 DOI: 10.3389/fimmu.2020.594653] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/07/2020] [Indexed: 12/18/2022] Open
Abstract
Malaria remains a significant contributor to the global burden of disease, with around 40% of the world's population at risk of Plasmodium infections. The development of an effective vaccine against the malaria parasite would mark a breakthrough in the fight to eradicate the disease. Over time, natural infection elicits a robust immune response against the blood stage of the parasite, providing protection against malaria. In recent years, we have gained valuable insight into the mechanisms by which IgG acts to prevent pathology and inhibit parasite replication, as well as the potential role of immunoglobulin M (IgM) in these processes. Here, we discuss recent advances in our understanding of the mechanisms, acquisition, and maintenance of naturally acquired immunity, and the relevance of these discoveries for the development of a potential vaccine against the blood stage of Plasmodium falciparum.
Collapse
Affiliation(s)
| | | | | | | | | | - Evelien M. Bunnik
- Department of Microbiology, Immunology and Molecular Genetics, Long School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| |
Collapse
|
8
|
Silva AR, Moraes BPT, Gonçalves-de-Albuquerque CF. Mediterranean Diet: Lipids, Inflammation, and Malaria Infection. Int J Mol Sci 2020; 21:ijms21124489. [PMID: 32599864 PMCID: PMC7350014 DOI: 10.3390/ijms21124489] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/05/2020] [Accepted: 02/15/2020] [Indexed: 12/11/2022] Open
Abstract
The Mediterranean diet (MedDiet) consists of consumption of vegetables and healthy oils and have beneficial effects on metabolic and inflammatory diseases. Our goal here is to discuss the role of fatty acid content in MedDiet, mostly omega-3, omega-6, and omega-9 on malaria. Malaria affects millions of people around the globe. The parasite Plasmodium causes the disease. The metabolic and inflammatory alterations in the severe forms have damaging consequences to the host. The lipid content in the MedDiet holds anti-inflammatory and pro-resolutive features in the host and have detrimental effects on the Plasmodium. The lipids from the diet impact the balance of pro- and anti-inflammation, thus, lipids intake from the diet is critical to parasite elimination and host tissue damage caused by an immune response. Herein, we go into the cellular and molecular mechanisms and targets of the MedDiet fatty acids in the host and the parasite, reviewing potential benefits of the MedDiet, on inflammation, malaria infection progression, and clinical outcome.
Collapse
Affiliation(s)
- Adriana R. Silva
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro 21040-900, Brazil;
- Programa de Neurociências da Universidade Federal Fluminense (UFF), Niterói 24020-141, Brazil
- Programa de Pós-Graduação em Biologia Celular e Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro 21040-900, Brazil
- Correspondence: or (A.R.S.); or (C.F.G.-d.-A.)
| | - Bianca P. T. Moraes
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro 21040-900, Brazil;
- Programa de Neurociências da Universidade Federal Fluminense (UFF), Niterói 24020-141, Brazil
- Laboratório de Imunofarmacologia, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro 20210-010, Brazil
| | - Cassiano F. Gonçalves-de-Albuquerque
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro 21040-900, Brazil;
- Programa de Neurociências da Universidade Federal Fluminense (UFF), Niterói 24020-141, Brazil
- Laboratório de Imunofarmacologia, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro 20210-010, Brazil
- Programa de Pós-Graduação em Biologia Molecular e Celular, UNIRIO, Rio de Janeiro 20210-010, Brazil
- Correspondence: or (A.R.S.); or (C.F.G.-d.-A.)
| |
Collapse
|
9
|
Obeng-Adjei N, Larremore DB, Turner L, Ongoiba A, Li S, Doumbo S, Yazew TB, Kayentao K, Miller LH, Traore B, Pierce SK, Buckee CO, Lavstsen T, Crompton PD, Tran TM. Longitudinal analysis of naturally acquired PfEMP1 CIDR domain variant antibodies identifies associations with malaria protection. JCI Insight 2020; 5:137262. [PMID: 32427581 DOI: 10.1172/jci.insight.137262] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/06/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUNDMalaria pathogenicity is determined, in part, by the adherence of Plasmodium falciparum-infected erythrocytes to the microvasculature mediated via specific interactions between P. falciparum erythrocyte membrane protein (PfEMP1) variant domains and host endothelial receptors. Naturally acquired antibodies against specific PfEMP1 variants can play an important role in clinical protection against malaria.METHODSWe evaluated IgG responses against a repertoire of PfEMP1 CIDR domain variants to determine the rate and order of variant-specific antibody acquisition and their association with protection against febrile malaria in a prospective cohort study conducted in an area of intense, seasonal malaria transmission.RESULTSUsing longitudinal data, we found that IgG antibodies against the pathogenic domain variants CIDRα1.7 and CIDRα1.8 were acquired the earliest. Furthermore, IgG antibodies against CIDRγ3 were associated with reduced prospective risk of febrile malaria and recurrent malaria episodes.CONCLUSIONThis study provides evidence that acquisition of IgG antibodies against PfEMP1 variants is ordered and demonstrates that antibodies against CIDRα1 domains are acquired the earliest in children residing in an area of intense, seasonal malaria transmission. Future studies will need to validate these findings in other transmission settings and determine the functional activity of these naturally acquired CIDR variant-specific antibodies.TRIAL REGISTRATIONClinicalTrials.gov NCT01322581.FUNDINGDivision of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH.
Collapse
Affiliation(s)
- Nyamekye Obeng-Adjei
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA.,Innate Immunity Research Unit, GlaxoSmithKline, Collegeville, Pennsylvania, USA
| | - Daniel B Larremore
- Department of Computer Science and.,BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Aissata Ongoiba
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Shanping Li
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Safiatou Doumbo
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | | | - Kassoum Kayentao
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, Maryland, USA
| | - Boubacar Traore
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | | | - Caroline O Buckee
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Peter D Crompton
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Tuan M Tran
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA.,Division of Infectious Diseases, Department of Medicine, and.,Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| |
Collapse
|
10
|
Loughland JR, Woodberry T, Field M, Andrew DW, SheelaNair A, Dooley NL, Piera KA, Amante FH, Kenangalem E, Price RN, Engwerda CR, Anstey NM, McCarthy JS, Boyle MJ, Minigo G. Transcriptional profiling and immunophenotyping show sustained activation of blood monocytes in subpatent Plasmodium falciparum infection. Clin Transl Immunology 2020; 9:e1144. [PMID: 32566226 PMCID: PMC7302943 DOI: 10.1002/cti2.1144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES Malaria, caused by Plasmodium infection, remains a major global health problem. Monocytes are integral to the immune response, yet their transcriptional and functional responses in primary Plasmodium falciparum infection and in clinical malaria are poorly understood. METHODS The transcriptional and functional profiles of monocytes were examined in controlled human malaria infection with P. falciparum blood stages and in children and adults with acute malaria. Monocyte gene expression and functional phenotypes were examined by RNA sequencing and flow cytometry at peak infection and compared to pre-infection or at convalescence in acute malaria. RESULTS In subpatent primary infection, the monocyte transcriptional profile was dominated by an interferon (IFN) molecular signature. Pathways enriched included type I IFN signalling, innate immune response and cytokine-mediated signalling. Monocytes increased TNF and IL-12 production upon in vitro toll-like receptor stimulation and increased IL-10 production upon in vitro parasite restimulation. Longitudinal phenotypic analyses revealed sustained significant changes in the composition of monocytes following infection, with increased CD14+CD16- and decreased CD14-CD16+ subsets. In acute malaria, monocyte CD64/FcγRI expression was significantly increased in children and adults, while HLA-DR remained stable. Although children and adults showed a similar pattern of differentially expressed genes, the number and magnitude of gene expression change were greater in children. CONCLUSIONS Monocyte activation during subpatent malaria is driven by an IFN molecular signature with robust activation of genes enriched in pathogen detection, phagocytosis, antimicrobial activity and antigen presentation. The greater magnitude of transcriptional changes in children with acute malaria suggests monocyte phenotypes may change with age or exposure.
Collapse
Affiliation(s)
- Jessica R Loughland
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia,Menzies School of Health ResearchDarwinNTAustralia
| | - Tonia Woodberry
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia,Present address:
The University of NewcastleCallaghanNSWAustralia
| | - Matt Field
- Australian Institute of Tropical Health and Medicine and Centre for Tropical Bioinformatics and Molecular BiologyJames Cook UniversityCairnsQLDAustralia,John Curtin School of Medical ResearchAustralian National UniversityCanberraACTAustralia
| | - Dean W Andrew
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia
| | - Arya SheelaNair
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia
| | | | - Kim A Piera
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia
| | - Fiona H Amante
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia
| | - Enny Kenangalem
- Timika Malaria Research ProgramPapuan Health and Community Development FoundationTimikaIndonesia,District Health AuthorityTimikaIndonesia
| | - Ric N Price
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia,Centre for Tropical Medicine and Global HealthNuffield Department of Clinical MedicineUniversity of OxfordOxfordUK,Mahidol‐Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
| | | | - Nicholas M Anstey
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia
| | | | - Michelle J Boyle
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia,Menzies School of Health ResearchDarwinNTAustralia
| | - Gabriela Minigo
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia,College of Health and Human SciencesCharles Darwin UniversityDarwinNTAustralia
| |
Collapse
|
11
|
Tessema SK, Nakajima R, Jasinskas A, Monk SL, Lekieffre L, Lin E, Kiniboro B, Proietti C, Siba P, Felgner PL, Doolan DL, Mueller I, Barry AE. Protective Immunity against Severe Malaria in Children Is Associated with a Limited Repertoire of Antibodies to Conserved PfEMP1 Variants. Cell Host Microbe 2020; 26:579-590.e5. [PMID: 31726028 DOI: 10.1016/j.chom.2019.10.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 08/08/2019] [Accepted: 10/18/2019] [Indexed: 01/31/2023]
Abstract
Extreme diversity of the major Plasmodium falciparum antigen, PfEMP1, poses a barrier to identifying targets of immunity to malaria. Here, we used protein microarrays containing hundreds of variants of the DBLα domain of PfEMP1 to cover the diversity of Papua New Guinean (PNG) parasites. Probing the plasma of a longitudinal cohort of malaria-exposed PNG children showed that group 2 DBLα antibodies were moderately associated with a lower risk of uncomplicated malaria, whereas individual variants were only weakly associated with clinical immunity. In contrast, antibodies to 85 individual group 1 and 2 DBLα variants were associated with a 70%-100% reduction in severe malaria. Of these, 17 variants were strong predictors of severe malaria. Analysis of full-length PfEMP1 sequences from PNG samples shows that these 17 variants are linked to pathogenic CIDR domains. This suggests that whereas immunity to uncomplicated malaria requires a broad repertoire of antibodies, immunity to severe malaria targets a subset of conserved variants. These findings provide insights into antimalarial immunity and potential antibody biomarkers for disease risk.
Collapse
Affiliation(s)
- Sofonias K Tessema
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia
| | - Rie Nakajima
- Physiology & Biophysics Department, Vaccine R&D Center, University of California, Irvine, Irvine 92697, CA, USA
| | - Algis Jasinskas
- Physiology & Biophysics Department, Vaccine R&D Center, University of California, Irvine, Irvine 92697, CA, USA
| | - Stephanie L Monk
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia
| | - Lea Lekieffre
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane 4006, QLD, Australia
| | - Enmoore Lin
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka 441, EHG, Papua New Guinea
| | - Benson Kiniboro
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka 441, EHG, Papua New Guinea
| | - Carla Proietti
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane 4006, QLD, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns 4878, QLD, Australia
| | - Peter Siba
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka 441, EHG, Papua New Guinea
| | - Philip L Felgner
- Physiology & Biophysics Department, Vaccine R&D Center, University of California, Irvine, Irvine 92697, CA, USA
| | - Denise L Doolan
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane 4006, QLD, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns 4878, QLD, Australia
| | - Ivo Mueller
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia; Department of Parasites and Insect Vectors, Institut Pasteur, Paris 75015, France
| | - Alyssa E Barry
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia.
| |
Collapse
|
12
|
Rambhatla JS, Turner L, Manning L, Laman M, Davis TME, Beeson JG, Mueller I, Warrel J, Theander TG, Lavstsen T, Rogerson SJ. Acquisition of Antibodies Against Endothelial Protein C Receptor-Binding Domains of Plasmodium falciparum Erythrocyte Membrane Protein 1 in Children with Severe Malaria. J Infect Dis 2019; 219:808-818. [PMID: 30365003 DOI: 10.1093/infdis/jiy564] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates parasite sequestration in postcapillary venules in P. falciparum malaria. PfEMP1 types can be classified based on their cysteine-rich interdomain region (CIDR) domains. Antibodies to different PfEMP1 types develop gradually after repeated infections as children age, and antibodies to specific CIDR types may confer protection. METHODS Levels of immunoglobulin G to 35 recombinant CIDR domains were measured by means of Luminex assay in acute-stage (baseline) and convalescent-stage plasma samples from Papua New Guinean children with severe or uncomplicated malaria and in healthy age-matched community controls. RESULTS At baseline, antibody levels were similar across the 3 groups. After infection, children with severe malaria had higher antibody levels than those with uncomplicated malaria against the endothelial protein C receptor (EPCR) binding CIDRα1 domains, and this difference was largely confined to older children. Antibodies to EPCR-binding domains increased from presentation to follow-up in severe malaria, but not in uncomplicated malaria. CONCLUSIONS The acquisition of antibodies against EPCR-binding CIDRα1 domains of PfEMP1 after a severe malaria episode suggest that EPCR-binding PfEMP1 may have a role in the pathogenesis of severe malaria in Papua New Guinea.
Collapse
Affiliation(s)
- Janavi S Rambhatla
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, Parkville
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Laurens Manning
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang
| | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch
| | - James G Beeson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Ivo Mueller
- Department of Medical Biology, University of Melbourne, Parkville.,Walter and Eliza Hall Institute of Medical Research, Parkville.,Parasite and Insect Vectors Department, Institut Pasteur, Paris, France
| | | | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Stephen J Rogerson
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, Parkville
| |
Collapse
|
13
|
Eacret JS, Gonzales DM, Franks RG, Burns JM. Immunization with merozoite surface protein 2 fused to a Plasmodium-specific carrier protein elicits strain-specific and strain-transcending, opsonizing antibody. Sci Rep 2019; 9:9022. [PMID: 31227760 PMCID: PMC6588637 DOI: 10.1038/s41598-019-45440-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/06/2019] [Indexed: 11/21/2022] Open
Abstract
Vaccine trials and cohort studies in Plasmodium falciparum endemic areas indicate that naturally-acquired and vaccine-induced antibodies to merozoite surface protein 2 (MSP2) are associated with resistance to malaria. These data indicate that PfMSP2 has significant potential as a component of a multi-antigen malaria vaccine. To overcome challenges encountered with subunit malaria vaccines, we established that the use of highly immunogenic rPfMSP8 as a carrier protein for leading vaccine candidates rPfMSP119 and rPfs25 facilitated antigen production, minimized antigenic competition and enhanced induction of functional antibodies. We applied this strategy to optimize a rPfMSP2 (3D7)-based subunit vaccine by producing unfused rPfMSP2 or chimeric rPfMSP2/8 in Escherichia coli. rPfMSP2 formed fibrils, which induced splenocyte proliferation in an antigen receptor-independent, TLR2-dependent manner. However, fusion to rPfMSP8 prevented rPfMSP2 amyloid-like fibril formation. Immunization of rabbits elicited high-titer anti-PfMSP2 antibodies that recognized rPfMSP2 of the 3D7 and FC27 alleles, as well as native PfMSP2. Competition assays revealed a difference in the specificity of antibodies induced by the two rPfMSP2-based vaccines, with evidence of epitope masking by rPfMSP2-associated fibrils. Rabbit anti-PfMSP2/8 was superior to rPfMSP2-elicited antibody at opsonizing P. falciparum merozoites for phagocytosis. These data establish rPfMSP8 as an effective carrier for a PfMSP2-based subunit malaria vaccine.
Collapse
Affiliation(s)
- Jacqueline S Eacret
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - Donna M Gonzales
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - Raymond G Franks
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - James M Burns
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA.
| |
Collapse
|
14
|
Akter J, Khoury DS, Aogo R, Lansink LIM, SheelaNair A, Thomas BS, Laohamonthonkul P, Pernold CPS, Dixon MWA, Soon MSF, Fogg LG, Engel JA, Elliott T, Sebina I, James KR, Cromer D, Davenport MP, Haque A. Plasmodium-specific antibodies block in vivo parasite growth without clearing infected red blood cells. PLoS Pathog 2019; 15:e1007599. [PMID: 30811498 PMCID: PMC6411214 DOI: 10.1371/journal.ppat.1007599] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/11/2019] [Accepted: 01/28/2019] [Indexed: 01/01/2023] Open
Abstract
Plasmodium parasites invade and multiply inside red blood cells (RBC). Through a cycle of maturation, asexual replication, rupture and release of multiple infective merozoites, parasitised RBC (pRBC) can reach very high numbers in vivo, a process that correlates with disease severity in humans and experimental animals. Thus, controlling pRBC numbers can prevent or ameliorate malaria. In endemic regions, circulating parasite-specific antibodies associate with immunity to high parasitemia. Although in vitro assays reveal that protective antibodies could control pRBC via multiple mechanisms, in vivo assessment of antibody function remains challenging. Here, we employed two mouse models of antibody-mediated immunity to malaria, P. yoelii 17XNL and P. chabaudi chabaudi AS infection, to study infection-induced, parasite-specific antibody function in vivo. By tracking a single generation of pRBC, we tested the hypothesis that parasite-specific antibodies accelerate pRBC clearance. Though strongly protective against homologous re-challenge, parasite-specific IgG did not alter the rate of pRBC clearance, even in the presence of ongoing, systemic inflammation. Instead, antibodies prevented parasites progressing from one generation of RBC to the next. In vivo depletion studies using clodronate liposomes or cobra venom factor, suggested that optimal antibody function required splenic macrophages and dendritic cells, but not complement C3/C5-mediated killing. Finally, parasite-specific IgG bound poorly to the surface of pRBC, yet strongly to structures likely exposed by the rupture of mature schizonts. Thus, in our models of humoral immunity to malaria, infection-induced antibodies did not accelerate pRBC clearance, and instead co-operated with splenic phagocytes to block subsequent generations of pRBC. Malaria occurs when Plasmodium parasites replicate inside red blood cells, with the number of parasitised cells (pRBC) correlating with disease severity. Antibodies are highly effective at controlling pRBC numbers in the bloodstream, and yet we know very little about how they function in vivo. Human in vitro studies predict that antibodies may function in a number of ways, including via phagocytes or different complement mechanisms. However, to date it has been challenging to explore how antibodies might control parasite numbers in vivo. Here, we have used a unique method in mice, where clearance and replication of a single cohort of pRBC was closely tracked in the presence of protective antibodies. Surprisingly, antibodies played no role whatsoever in accelerating the removal of pRBC. Instead, antibodies were highly effective at preventing parasites from progressing from one generation of pRBC to the next. This process partly depended on host phagocytes. However, we found no role for complement-mediated direct killing. Together, our in vivo data suggest in mouse models that naturally-acquired antibodies do not clear pRBC, and instead prevent transition from one red blood cell to the next.
Collapse
Affiliation(s)
- Jasmin Akter
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - David S. Khoury
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
| | - Rosemary Aogo
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
| | | | - Arya SheelaNair
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Bryce S. Thomas
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | | | | | - Matthew W. A. Dixon
- University of Melbourne, Department of Biochemistry and Molecular Biology, Melbourne, Victoria, Australia
| | - Megan S. F. Soon
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Lily G. Fogg
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Jessica A. Engel
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Trish Elliott
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Ismail Sebina
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Kylie R. James
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Deborah Cromer
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
| | - Miles P. Davenport
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
- * E-mail: (MPD); (AH)
| | - Ashraful Haque
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
- * E-mail: (MPD); (AH)
| |
Collapse
|
15
|
Chan JA, Boyle MJ, Moore KA, Reiling L, Lin Z, Hasang W, Avril M, Manning L, Mueller I, Laman M, Davis T, Smith JD, Rogerson SJ, Simpson JA, Fowkes FJI, Beeson JG. Antibody Targets on the Surface of Plasmodium falciparum-Infected Erythrocytes That Are Associated With Immunity to Severe Malaria in Young Children. J Infect Dis 2019; 219:819-828. [PMID: 30365004 PMCID: PMC6376912 DOI: 10.1093/infdis/jiy580] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/15/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the microvasculature contributes to pathogenesis of severe malaria in children. This mechanism is mediated by antigens expressed on the IE surface. However, knowledge of specific targets and functions of antibodies to IE surface antigens that protect against severe malaria is limited. METHODS Antibodies to IE surface antigens were examined in a case-control study of young children in Papua New Guinea presenting with severe or uncomplicated malaria (n = 448), using isolates with a virulent phenotype associated with severe malaria, and functional opsonic phagocytosis assays. We used genetically modified isolates and recombinant P. falciparum erythrocyte membrane protein 1 (PfEMP1) domains to quantify PfEMP1 as a target of antibodies associated with disease severity. RESULTS Antibodies to the IE surface and recombinant PfEMP1 domains were significantly higher in uncomplicated vs severe malaria and were boosted following infection. The use of genetically modified P. falciparum revealed that PfEMP1 was a major target of antibodies and that PfEMP1-specific antibodies were associated with reduced odds of severe malaria. Furthermore, antibodies promoting the opsonic phagocytosis of IEs by monocytes were lower in those with severe malaria. CONCLUSIONS Findings suggest that PfEMP1 is a dominant target of antibodies associated with reduced risk of severe malaria, and function in part by promoting opsonic phagocytosis.
Collapse
Affiliation(s)
- Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Michelle J Boyle
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Kerryn A Moore
- Burnet Institute for Medical Research and Public Health, Melbourne
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne
| | - Linda Reiling
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Zaw Lin
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Wina Hasang
- Department of Medicine, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Australia
| | - Marion Avril
- Center for Infectious Diseases Research, Seattle, Washington
| | - Laurens Manning
- Papua New Guinea Institute of Medical Research, Madang
- University of Western Australia, Perth
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang
| | | | - Joseph D Smith
- Center for Infectious Diseases Research, Seattle, Washington
| | - Stephen J Rogerson
- Department of Medicine, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
| | - Freya J I Fowkes
- Burnet Institute for Medical Research and Public Health, Melbourne
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
- Department of Infectious Diseases, Monash University, Melbourne, Victoria, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne
- Department of Medicine, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Australia
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
16
|
Barua P, Beeson JG, Maleta K, Ashorn P, Rogerson SJ. The impact of early life exposure to Plasmodium falciparum on the development of naturally acquired immunity to malaria in young Malawian children. Malar J 2019; 18:11. [PMID: 30658632 PMCID: PMC6339377 DOI: 10.1186/s12936-019-2647-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 01/12/2019] [Indexed: 11/23/2022] Open
Abstract
Background Antibodies targeting malaria blood-stage antigens are important targets of naturally acquired immunity, and may act as valuable biomarkers of malaria exposure. Methods Six-hundred and one young Malawian children from a randomized trial of prenatal nutrient supplementation with iron and folic acid or pre- and postnatal multiple micronutrients or lipid-based nutrient supplements were followed up weekly at home and febrile episodes were investigated for malaria from birth to 18 months of age. Antibodies were measured for 601 children against merozoite surface proteins (MSP1 19kD, MSP2), erythrocyte binding antigen 175 (EBA175), reticulocyte binding protein homologue 2 (Rh2A9), schizont extract and variant surface antigens expressed by Plasmodium falciparum-infected erythrocytes (IE) at 18 months of age. The antibody measurement data was related to concurrent malaria infection and to documented episodes of clinical malaria. Results At 18 months of age, antibodies were significantly higher among parasitaemic than aparasitaemic children. Antibody levels against MSP1 19kD, MSP2, schizont extract, and IE variant surface antigens were significantly higher in children who had documented episodes of malaria than in children who did not. Antibody levels did not differ between children with single or multiple malaria episodes before 18 months, nor between children who had malaria before 6 months of age or between 6 and 18 months. Conclusions Antibodies to merozoite and IE surface antigens increased following infection in early childhood, but neither age at first infection nor number of malaria episodes substantially affected antibody acquisition. These findings have implications for malaria surveillance during early childhood in the context of elimination. Trials registration Clinical Trials Registration: NCT01239693 (Date of registration: 11-10-2010). URL: http://www.ilins.org
Collapse
Affiliation(s)
- Priyanka Barua
- The Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, 3000, Australia.,Department of Zoology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - James G Beeson
- The Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, 3000, Australia.,Burnet Institute, Melbourne, VIC, 3004, Australia.,Department of Microbiology and Central Clinical School, Monash University, Melbourne, VIC, 3800, Australia
| | - Kenneth Maleta
- School of Public Health and Family Medicine, University of Malawi, Blantyre 3, Malawi
| | - Per Ashorn
- Faculty of Medicine and Life Sciences, University of Tampere and Tampere University Hospital, 33100, Tampere, Finland.,Research and Development, Maternal, Newborn and Adolescent Health, World Health Organization, Geneva 27, 1211, Switzerland
| | - Stephen J Rogerson
- The Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, 3000, Australia.
| |
Collapse
|
17
|
Ortega-Pajares A, Rogerson SJ. The Rough Guide to Monocytes in Malaria Infection. Front Immunol 2018; 9:2888. [PMID: 30581439 PMCID: PMC6292935 DOI: 10.3389/fimmu.2018.02888] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/26/2018] [Indexed: 12/14/2022] Open
Abstract
While half of the world's population is at risk of malaria, the most vulnerable are still children under five, pregnant women and returning travelers. Anopheles mosquitoes transmit malaria parasites to the human host; but how Plasmodium interact with the innate immune system remains largely unexplored. The most recent advances prove that monocytes are a key component to control parasite burden and to protect host from disease. Monocytes' protective roles include phagocytosis, cytokine production and antigen presentation. However, monocytes can be involved in pathogenesis and drive inflammation and sequestration of infected red blood cells in organs such as the brain, placenta or lungs by secreting cytokines that upregulate expression of endothelial adhesion receptors. Plasmodium DNA, hemozoin or extracellular vesicles can impair the function of monocytes. With time, reinfections with Plasmodium change the relative proportion of monocyte subsets and their physical properties. These changes relate to clinical outcomes and might constitute informative biomarkers of immunity. More importantly, at the molecular level, transcriptional, metabolic or epigenetic changes can “prime” monocytes to alter their responses in future encounters with Plasmodium. This mechanism, known as trained immunity, challenges the traditional view of monocytes as a component of the immune system that lacks memory. Overall, this rough guide serves as an update reviewing the advances made during the past 5 years on understanding the role of monocytes in innate immunity to malaria.
Collapse
Affiliation(s)
- Amaya Ortega-Pajares
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Rogerson
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
18
|
Barua P, Chandrasiri UP, Beeson JG, Dewey KG, Maleta K, Ashorn P, Rogerson SJ. Effect of nutrient supplementation on the acquisition of humoral immunity to Plasmodium falciparum in young Malawian children. Malar J 2018; 17:74. [PMID: 29415730 PMCID: PMC5804088 DOI: 10.1186/s12936-018-2224-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/31/2018] [Indexed: 11/17/2022] Open
Abstract
Background There is evidence that suggests that undernutrition has a detrimental effect on malarial immunity in children. The aim of the study was to discover whether nutrient supplementation improved development of malarial antibody immunity in children up to 18 months of age. Methods The study was conducted with a subset of 432 Malawian children from a randomized controlled trial of nutritional supplements. The arms included pre- and postnatal small-quantity lipid-based nutrient supplements for both mother and child; prenatal supplementation with iron and folic acid; and pre- and postnatal supplementation with multiple micronutrients. Paired plasma samples were collected at 6 and 18 months of age. The levels of antibodies against merozoite surface protein 1 (MSP1 19kD) and MSP2, erythrocyte binding antigen 175 (EBA175), reticulocyte binding protein homologue 2A (Rh2A9), schizont extract and variant antigens expressed on the surface of infected erythrocytes were measured. Results At 18 months of age, 5.4% of children were parasitaemic by microscopy and 49.1% were anaemic. Antibodies to the tested merozoite antigens and schizont extract increased between 6 and 18 months and this increase was statistically significant for MSP1, MSP2 and EBA175 (p < 0.0001) whereas IgG to variant surface antigens decreased with increasing age (p < 0.0001). However, the supplementation type did not have any impact on the prevalence or levels of antibodies at either 6 or 18 months of age to any of the tested malaria antigens in either univariate analysis or multivariate analysis after adjusting for covariates. Conclusions Pre- and postnatal lipid-based nutrient supplementation did not alter malaria antibody acquisition during infancy, compared to prenatal supplementation with iron and folic acid or pre- and postnatal supplementation with multiple micronutrients. Trail registeration Clinicaltrials.gov registration number NCT01239693
Collapse
Affiliation(s)
- Priyanka Barua
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Upeksha P Chandrasiri
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - James G Beeson
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia.,Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia.,Monash University, Melbourne, VIC, Australia
| | | | | | - Per Ashorn
- University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Stephen J Rogerson
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia.
| |
Collapse
|
19
|
Mugyenyi CK, Elliott SR, Yap XZ, Feng G, Boeuf P, Fegan G, Osier FFH, Fowkes FJI, Avril M, Williams TN, Marsh K, Beeson JG. Declining Malaria Transmission Differentially Impacts the Maintenance of Humoral Immunity to Plasmodium falciparum in Children. J Infect Dis 2017; 216:887-898. [PMID: 28973483 DOI: 10.1093/infdis/jix370] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/31/2017] [Indexed: 12/13/2022] Open
Abstract
Background We investigated the poorly understood impact of declining malaria transmission on maintenance of antibodies to Plasmodium falciparum merozoite antigens and infected erythrocytes (IEs), including functional immunity. Methods In a 3-year longitudinal cohort of 300 Kenyan children, antibodies to different AMA1 and MSP2 alleles of merozoites, IE surface antigens, and antibody functional activities were quantified. Results Over a period in which malaria transmission declined markedly, AMA1 and MSP2 antibodies decreased substantially; estimated half-lives of antibody duration were 0.8 year and 1-3 years, respectively. However, 69%-74% of children maintained their seropositivity to AMA1 alleles and 42%-52% to MSP2 alleles. Levels and prevalence of antimerozoite antibodies were consistently associated with increasing age and concurrent parasitemia. Antibodies promoting opsonic phagocytosis of merozoites declined rapidly (half-life, 0.15 years). In contrast, complement-fixing antibodies to merozoites did not decline and antibodies to IE surface antigens expressing virulent phenotypes were much better maintained (half-life, 4-10 years). Conclusions A decline in malaria transmission is associated with reduction in naturally acquired immunity. However, loss of immunity is not universal; some key functional responses and antibodies to IEs were better maintained and these may continue to provide some protection. Findings have implications for malaria surveillance and control measures and informing vaccine development.
Collapse
Affiliation(s)
- Cleopatra K Mugyenyi
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine, Coast, KEMRI-Wellcome Trust Research Programme, Kilifi.,Burnet Institute, Melbourne
| | | | - Xi Zen Yap
- Burnet Institute, Melbourne.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Victoria, Australia
| | | | - Philippe Boeuf
- Burnet Institute, Melbourne.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Victoria, Australia
| | - Gregory Fegan
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine, Coast, KEMRI-Wellcome Trust Research Programme, Kilifi
| | - Faith F H Osier
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine, Coast, KEMRI-Wellcome Trust Research Programme, Kilifi.,Burnet Institute, Melbourne.,Department of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Germany
| | - Freya J I Fowkes
- Burnet Institute, Melbourne.,Department of Epidemiology and Preventive Medicine, Monash University.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Victoria, Australia
| | - Marion Avril
- Centre for Infectious Disease Research, Seattle, Washington
| | - Thomas N Williams
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine, Coast, KEMRI-Wellcome Trust Research Programme, Kilifi.,Imperial College, London, United Kingdom
| | - Kevin Marsh
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine, Coast, KEMRI-Wellcome Trust Research Programme, Kilifi
| | - James G Beeson
- Burnet Institute, Melbourne.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Victoria, Australia.,Central Clinical School and Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|