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Hodgson SH, Llewellyn D, Silk SE, Milne KH, Elias SC, Miura K, Kamuyu G, Juma EA, Magiri C, Muia A, Jin J, Spencer AJ, Longley RJ, Mercier T, Decosterd L, Long CA, Osier FH, Hoffman SL, Ogutu B, Hill AVS, Marsh K, Draper SJ. Changes in Serological Immunology Measures in UK and Kenyan Adults Post-controlled Human Malaria Infection. Front Microbiol 2016; 7:1604. [PMID: 27790201 PMCID: PMC5061779 DOI: 10.3389/fmicb.2016.01604] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 09/26/2016] [Indexed: 11/15/2022] Open
Abstract
Background: The timing of infection is closely determined in controlled human malaria infection (CHMI) studies, and as such they provide a unique opportunity to dissect changes in immunological responses before and after a single infection. The first Kenyan Challenge Study (KCS) (Pan African Clinical Trial Registry: PACTR20121100033272) was performed in 2013 with the aim of establishing the CHMI model in Kenya. This study used aseptic, cryopreserved, attenuated Plasmodium falciparum sporozoites administered by needle and syringe (PfSPZ Challenge) and was the first to evaluate parasite dynamics post-CHMI in individuals with varying degrees of prior exposure to malaria. Methods: We describe detailed serological and functional immunological responses pre- and post-CHMI for participants in the KCS and compare these with those from malaria-naïve UK volunteers who also underwent CHMI (VAC049) (ClinicalTrials.gov NCT01465048) using PfSPZ Challenge. We assessed antibody responses to three key blood-stage merozoite antigens [merozoite surface protein 1 (MSP1), apical membrane protein 1 (AMA1), and reticulocyte-binding protein homolog 5 (RH5)] and functional activity using two candidate measures of anti-merozoite immunity; the growth inhibition activity (GIA) assay and the antibody-dependent respiratory burst activity (ADRB) assay. Results:Clear serological differences were observed pre- and post-CHMI by ELISA between malaria-naïve UK volunteers in VAC049, and Kenyan volunteers who had prior malaria exposure. Antibodies to AMA1 and schizont extract correlated with parasite multiplication rate (PMR) post-CHMI in KCS. Serum from volunteer 110 in KCS, who demonstrated a dramatically reduced PMR in vivo, had no in vitro GIA prior to CHMI but the highest level of ADRB activity. A significant difference in ADRB activity was seen between KCS volunteers with minimal and definite prior exposure to malaria and significant increases were seen in ADRB activity post-CHMI in Kenyan volunteers. Quinine and atovaquone/proguanil, previously assumed to be removed by IgG purification, were identified as likely giving rise to aberrantly high in vitro GIA results. Conclusions: The ADRB activity assay is a promising functional assay that warrants further investigation as a measure of prior exposure to malaria and predictor of control of parasite growth. The CHMI model can be used to evaluate potential measures of naturally-acquired immunity to malaria.
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Affiliation(s)
| | | | - Sarah E Silk
- The Jenner Institute, University of Oxford Oxford, UK
| | | | - Sean C Elias
- The Jenner Institute, University of Oxford Oxford, UK
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIH-National Institute of Allergy and Infectious Diseases Rockville, MD, USA
| | - Gathoni Kamuyu
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute-Wellcome Trust Kilifi, Kenya
| | - Elizabeth A Juma
- Centre for Clinical Research, Kenya Medical Research InstituteNairobi, Kenya; Centre for Research in Therapeutic Sciences, Strathmore UniversityNairobi, Kenya
| | - Charles Magiri
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya
| | - Alfred Muia
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya
| | - Jing Jin
- The Jenner Institute, University of Oxford Oxford, UK
| | | | | | - Thomas Mercier
- Division of Clinical Pharmacology, Hôpital Beaumont, Université de Lausanne Lausanne, Switzerland
| | - Laurent Decosterd
- Division of Clinical Pharmacology, Hôpital Beaumont, Université de Lausanne Lausanne, Switzerland
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIH-National Institute of Allergy and Infectious Diseases Rockville, MD, USA
| | - Faith H Osier
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute-Wellcome Trust Kilifi, Kenya
| | | | - Bernhards Ogutu
- Centre for Clinical Research, Kenya Medical Research InstituteNairobi, Kenya; Centre for Research in Therapeutic Sciences, Strathmore UniversityNairobi, Kenya
| | | | - Kevin Marsh
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute-Wellcome TrustKilifi, Kenya; Department of Tropical Medicine, University of OxfordOxford, UK
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Hickey BW, Lumsden JM, Reyes S, Sedegah M, Hollingdale MR, Freilich DA, Luke TC, Charoenvit Y, Goh LM, Berzins MP, Bebris L, Sacci JB, De La Vega P, Wang R, Ganeshan H, Abot EN, Carucci DJ, Doolan DL, Brice GT, Kumar A, Aguiar J, Nutman TB, Leitman SF, Hoffman SL, Epstein JE, Richie TL. Mosquito bite immunization with radiation-attenuated Plasmodium falciparum sporozoites: safety, tolerability, protective efficacy and humoral immunogenicity. Malar J 2016; 15:377. [PMID: 27448805 PMCID: PMC4957371 DOI: 10.1186/s12936-016-1435-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/09/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In this phase 1 clinical trial, healthy adult, malaria-naïve subjects were immunized with radiation-attenuated Plasmodium falciparum sporozoites (PfRAS) by mosquito bite and then underwent controlled human malaria infection (CHMI). The PfRAS model for immunization against malaria had previously induced >90 % sterile protection against homologous CHMI. This study was to further explore the safety, tolerability and protective efficacy of the PfRAS model and to provide biological specimens to characterize protective immune responses and identify protective antigens in support of malaria vaccine development. METHODS Fifty-seven subjects were screened, 41 enrolled and 30 received at least one immunization. The true-immunized subjects received PfRAS via mosquito bite and the mock-immunized subjects received mosquito bites from irradiated uninfected mosquitoes. Sera and peripheral blood mononuclear cells (PBMCs) were collected before and after PfRAS immunizations. RESULTS Immunization with PfRAS was generally safe and well tolerated, and repeated immunization via mosquito bite did not appear to increase the risk or severity of AEs. Local adverse events (AEs) of true-immunized and mock-immunized groups consisted of erythaema, papules, swelling, and induration and were consistent with reactions from mosquito bites seen in nature. Two subjects, one true- and one mock-immunized, developed large local reactions that completely resolved, were likely a result of mosquito salivary antigens, and were withdrawn from further participation as a safety precaution. Systemic AEs were generally rare and mild, consisting of headache, myalgia, nausea, and low-grade fevers. Two true-immunized subjects experienced fever, malaise, myalgia, nausea, and rigours approximately 16 h after immunization. These symptoms likely resulted from pre-formed antibodies interacting with mosquito salivary antigens. Ten subjects immunized with PfRAS underwent CHMI and five subjects (50 %) were sterilely protected and there was a significant delay to parasitaemia in the other five subjects. All ten subjects developed humoral immune responses to whole sporozoites and to the circumsporozoite protein prior to CHMI, although the differences between protected and non-protected subjects were not statistically significant for this small sample size. CONCLUSIONS The protective efficacy of this clinical trial (50 %) was notably less than previously reported (>90 %). This may be related to differences in host genetics or the inherent variability in mosquito biting behavior and numbers of sporozoites injected. Differences in trial procedures, such as the use of leukapheresis prior to CHMI and of a longer interval between the final immunization and CHMI in these subjects compared to earlier trials, may also have reduced protective efficacy. This trial has been retrospectively registered at ISRCTN ID 17372582, May 31, 2016.
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Affiliation(s)
- Bradley W. Hickey
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Joanne M. Lumsden
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Sharina Reyes
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Martha Sedegah
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Michael R. Hollingdale
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Daniel A. Freilich
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Thomas C. Luke
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Yupin Charoenvit
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Lucy M. Goh
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Mara P. Berzins
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Lolita Bebris
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - John B. Sacci
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Patricia De La Vega
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Ruobing Wang
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Harini Ganeshan
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Esteban N. Abot
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, MD USA
| | - Daniel J. Carucci
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Denise L. Doolan
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Gary T. Brice
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Anita Kumar
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Joao Aguiar
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Thomas B. Nutman
- />Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - Susan F. Leitman
- />Department of Transfusion Medicine, National Institutes of Health Clinical Center, Bethesda, MD USA
| | - Stephen L. Hoffman
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Sanaria Inc., Rockville, MD USA
| | - Judith E. Epstein
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
| | - Thomas L. Richie
- />US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD USA
- />Sanaria Inc., Rockville, MD USA
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Hemmink JD, Weir W, MacHugh ND, Graham SP, Patel E, Paxton E, Shiels B, Toye PG, Morrison WI, Pelle R. Limited genetic and antigenic diversity within parasite isolates used in a live vaccine against Theileria parva. Int J Parasitol 2016; 46:495-506. [PMID: 27080723 PMCID: PMC4935670 DOI: 10.1016/j.ijpara.2016.02.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/17/2016] [Accepted: 02/29/2016] [Indexed: 11/02/2022]
Abstract
An infection and treatment protocol is used to vaccinate cattle against Theileria parva infection. Due to incomplete cross-protection between different parasite isolates, a mixture of three isolates, termed the Muguga cocktail, is used for vaccination. While vaccination of cattle in some regions provides high levels of protection, some animals are not protected against challenge with buffalo-derived T. parva. Knowledge of the genetic composition of the Muguga cocktail vaccine is required to understand how vaccination is able to protect against field challenge and to identify the potential limitations of the vaccine. The aim of the current study was to determine the extent of genetic and antigenic diversity within the parasite isolates that constitute the Muguga cocktail. High throughput multi-locus sequencing of antigen-encoding loci was performed in parallel with typing using a panel of micro- and mini-satellite loci. The former focused on genes encoding CD8(+) T cell antigens, believed to be relevant to protective immunity. The results demonstrate that each of the three component stocks of the cocktail contains limited parasite genotypic diversity, with single alleles detected at many gene/satellite loci and, moreover, that two of the components show a very high level of similarity. Thus, the vaccine incorporates very little of the genetic and antigenic diversity observed in field populations of T. parva. The presence of alleles at low frequency (<10%) within vaccine component populations also points to the possibility of variability in the content of vaccine doses and the potential for loss of allelic diversity during tick passage. The results demonstrate that there is scope to modify the content of the vaccine in order to enhance its diversity and thus its potential for providing broad protection. The ability to accurately quantify genetic diversity in vaccine component stocks will facilitate improved quality control procedures designed to ensure the long-term efficacy of the vaccine.
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Affiliation(s)
- Johanneke D Hemmink
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
| | - William Weir
- College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Henry Wellcome Building, Garscube Campus, Bearsden Road, Glasgow G61 1QH, UK
| | - Niall D MacHugh
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
| | - Simon P Graham
- The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Ekta Patel
- The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Edith Paxton
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK
| | - Brian Shiels
- College of Medical, Veterinary and Life Sciences, Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Henry Wellcome Building, Garscube Campus, Bearsden Road, Glasgow G61 1QH, UK
| | - Philip G Toye
- The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - W Ivan Morrison
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK.
| | - Roger Pelle
- The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
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Richie TL, Billingsley PF, Sim BKL, James ER, Chakravarty S, Epstein JE, Lyke KE, Mordmüller B, Alonso P, Duffy PE, Doumbo OK, Sauerwein RW, Tanner M, Abdulla S, Kremsner PG, Seder RA, Hoffman SL. Progress with Plasmodium falciparum sporozoite (PfSPZ)-based malaria vaccines. Vaccine 2015; 33:7452-61. [PMID: 26469720 PMCID: PMC5077156 DOI: 10.1016/j.vaccine.2015.09.096] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 09/28/2015] [Accepted: 09/28/2015] [Indexed: 12/04/2022]
Abstract
Sanaria Inc. has developed methods to manufacture, purify and cryopreserve aseptic Plasmodium falciparum (Pf) sporozoites (SPZ), and is using this platform technology to develop an injectable PfSPZ-based vaccine that provides high-grade, durable protection against infection with Pf malaria. Several candidate vaccines are being developed and tested, including PfSPZ Vaccine, in which the PfSPZ are attenuated by irradiation, PfSPZ-CVac, in which fully infectious PfSPZ are attenuated in vivo by concomitant administration of an anti-malarial drug, and PfSPZ-GA1, in which the PfSPZ are attenuated by gene knockout. Forty-three research groups in 15 countries, organized as the International PfSPZ Consortium (I-PfSPZ-C), are collaborating to advance this program by providing intellectual, clinical, and financial support. Fourteen clinical trials of these products have been completed in the USA, Europe and Africa, two are underway and at least 12 more are planned for 2015-2016 in the US (four trials), Germany (2 trials), Tanzania, Kenya, Mali, Burkina Faso, Ghana and Equatorial Guinea. Sanaria anticipates application to license a first generation product as early as late 2017, initially to protect adults, and a year later to protect all persons >6 months of age for at least six months. Improved vaccine candidates will be advanced as needed until the following requirements have been met: long-term protection against natural transmission, excellent safety and tolerability, and operational feasibility for population-wide administration. Here we describe the three most developed whole PfSPZ vaccine candidates, associated clinical trials, initial plans for licensure and deployment, and long-term objectives for a final product suitable for mass administration to achieve regional malaria elimination and eventual global eradication.
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Affiliation(s)
| | | | | | | | | | | | - Kirsten E Lyke
- Center for Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | | | - Pedro Alonso
- Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, United States
| | - Ogobara K Doumbo
- Malaria Research and Training Center, University of Bamako, Bamako, Mali
| | | | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Salim Abdulla
- Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Peter G Kremsner
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, United States
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Large screen approaches to identify novel malaria vaccine candidates. Vaccine 2015; 33:7496-505. [PMID: 26428458 DOI: 10.1016/j.vaccine.2015.09.059] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 09/07/2015] [Accepted: 09/15/2015] [Indexed: 11/20/2022]
Abstract
Until recently, malaria vaccine development efforts have focused almost exclusively on a handful of well characterized Plasmodium falciparum antigens. Despite dedicated work by many researchers on different continents spanning more than half a century, a successful malaria vaccine remains elusive. Sequencing of the P. falciparum genome has revealed more than five thousand genes, providing the foundation for systematic approaches to discover candidate vaccine antigens. We are taking advantage of this wealth of information to discover new antigens that may be more effective vaccine targets. Herein, we describe different approaches to large-scale screening of the P. falciparum genome to identify targets of either antibody responses or T cell responses using human specimens collected in Controlled Human Malaria Infections (CHMI) or under conditions of natural exposure in the field. These genome, proteome and transcriptome based approaches offer enormous potential for the development of an efficacious malaria vaccine.
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