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Tumwine-Downey I, Deroost K, Levy P, McLaughlin S, Hosking C, Langhorne J. Antibody-dependent immune responses elicited by blood stage-malaria infection contribute to protective immunity to the pre-erythrocytic stages. CURRENT RESEARCH IN IMMUNOLOGY 2022; 4:100054. [PMID: 36593995 PMCID: PMC9803926 DOI: 10.1016/j.crimmu.2022.100054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 11/21/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Advances in transcriptomics and proteomics have revealed that different life-cycle stages of the malaria parasite, Plasmodium, share antigens, thus allowing for the possibility of eliciting immunity to a parasite life-cycle stage that has not been experienced before. Using the Plasmodium chabaudi (AS strain) model of malaria in mice, we investigated how isolated exposure to blood-stage infection, bypassing a liver-stage infection, yields significant protection to sporozoite challenge resulting in lower liver parasite burdens. Antibodies are the main immune driver of this protection. Antibodies induced by blood-stage infection recognise proteins on the surface of sporozoites and can impair sporozoite gliding motility in vitro, suggesting a possible function in vivo. Furthermore, mice lacking B cells and/or secreted antibodies are not protected against a sporozoite challenge in mice that had a previous blood-stage infection. Conversely, effector CD4+ and CD8+ T cells do not seem to play a role in protection from sporozoite challenge of mice previously exposed only to the blood stages of P. chabaudi. The protective response against pre-erythrocytic stages can be induced by infections initiated by serially passaged blood-stage parasites as well as recently mosquito transmitted parasites and is effective against a different strain of P. chabaudi (CB strain), but not against another rodent malaria species, P. yoelii. The possibility to induce protective cross-stage antibodies advocates the need to consider both stage-specific and cross-stage immune responses to malaria, as natural infection elicits exposure to all life-cycle stages. Future investigation into these cross-stage antibodies allows the opportunity for candidate antigens to contribute to malaria vaccine development.
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Affiliation(s)
| | | | | | | | | | - Jean Langhorne
- Corresponding author. Malaria Immunology Laboratory, Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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2
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Deroost K, Alder C, Hosking C, McLaughlin S, Lin JW, Lewis MD, Saavedra-Torres Y, Addy JWG, Levy P, Giorgalli M, Langhorne J. Tissue macrophages and interferon-gamma signalling control blood-stage Plasmodium chabaudi infections derived from mosquito-transmitted parasites. CURRENT RESEARCH IN IMMUNOLOGY 2021; 2:104-119. [PMID: 34532703 PMCID: PMC8428512 DOI: 10.1016/j.crimmu.2021.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 11/19/2022] Open
Abstract
Natural infection with Plasmodium parasites, the causative agents of malaria, occurs via mosquito vectors. However, most of our knowledge of the immune response to the blood stages of Plasmodium is from infections initiated by injection of serially blood-passaged infected red blood cells, resulting in an incomplete life cycle in the mammalian host. Vector transmission of the rodent malaria parasite, Plasmodium chabaudi chabaudi AS has been shown to give rise to a more attenuated blood-stage infection in C57Bl/6J mice, when compared to infections initiated with serially blood-passaged P. chabaudi-infected red blood cells. In mouse models, the host immune response induced by parasites derived from natural mosquito transmission is likely to more closely resemble the immune responses to Plasmodium infections in humans. It is therefore important to determine how the host response differs between the two types of infections. As the spleen is considered to be a major contributor to the protective host response to P. chabaudi, we carried out a comparative transcriptomic analysis of the splenic response to recently mosquito-transmitted and serially blood-passaged parasites in C57Bl/6J mice. The attenuated infection arising from recently mosquito-transmitted parasites is characterised by an earlier and stronger myeloid- and IFNγ-related response. Analyses of spleen lysates from the two infections similarly showed stronger or earlier inflammatory cytokine and chemokine production in the recently mosquito-transmitted blood-stage infections. Furthermore, tissue macrophages, including red pulp macrophages, and IFNγ-signalling in myeloid cells, are required for the early control of P. chabaudi recently mosquito-transmitted parasites, thus contributing to the attenuation of mosquito-transmitted infections. The molecules responsible for this early activation response to recently-transmitted blood-stage parasites in mice would be important to identify, as they may help to elucidate the nature of the initial interactions between blood-stage parasites and the host immune system in naturally transmitted malaria. Attenuation of recently transmitted malaria happens at blood stage of infection. Stronger or earlier inflammatory cytokine and chemokine production. Tissue macrophages, including red pulp macrophages, contribute to attenuation. IFNγ-signalling in myeloid cells is required for early control of P. chabaudi AS.
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3
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Gibbins MP, Müller K, Matuschewski K, Silvie O, Hafalla JCR. Inferior T cell immunogenicity of a Plasmodium berghei model liver stage antigen expressed throughout pre-erythrocytic maturation. Parasite Immunol 2021; 43:e12877. [PMID: 34515999 DOI: 10.1111/pim.12877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 12/01/2022]
Abstract
Sporozoite antigens are the basis of a number of malaria vaccines being tested, but the contribution of antigens expressed during subsequent liver stage development to pre-erythrocytic stage immunity is poorly understood. We previously showed that, following immunisation with radiation attenuated sporozoites (RAS), a model epitope embedded in a sporozoite surface protein elicited robust CD8+ T cell responses, whilst the same epitope in a liver stage antigen induced inferior responses. Since RAS arrest early in their development in host hepatocytes, we hypothesised that extending parasite maturation in the liver could considerably improve the epitope-specific CD8+ T cell response. Here, we employed a late liver stage arrested parasite model, azithromycin prophylaxis alongside live sporozoites, to increase expression of the model epitope until full liver stage maturation. Strikingly, this alternative immunisation strategy, which has been shown to elicit superior protection, failed to improve the resulting epitope-specific CD8+ T cell responses. Our findings support the notion that liver stage antigens are poorly immunogenic and provide additional caution about prioritising antigens for vaccine development based solely on immunogenicity.
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Affiliation(s)
- Matthew P Gibbins
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Katja Müller
- Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Institute of Biology, Humboldt University, Berlin, Germany
| | - Kai Matuschewski
- Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Institute of Biology, Humboldt University, Berlin, Germany
| | - Olivier Silvie
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, CIMI-Paris, Paris, France
| | - Julius Clemence R Hafalla
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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4
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Mwakingwe-Omari A, Healy SA, Lane J, Cook DM, Kalhori S, Wyatt C, Kolluri A, Marte-Salcedo O, Imeru A, Nason M, Ding LK, Decederfelt H, Duan J, Neal J, Raiten J, Lee G, Hume JCC, Jeon JE, Ikpeama I, Kc N, Chakravarty S, Murshedkar T, Church LWP, Manoj A, Gunasekera A, Anderson C, Murphy SC, March S, Bhatia SN, James ER, Billingsley PF, Sim BKL, Richie TL, Zaidi I, Hoffman SL, Duffy PE. Two chemoattenuated PfSPZ malaria vaccines induce sterile hepatic immunity. Nature 2021; 595:289-294. [PMID: 34194041 PMCID: PMC11127244 DOI: 10.1038/s41586-021-03684-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 06/01/2021] [Indexed: 02/06/2023]
Abstract
The global decline in malaria has stalled1, emphasizing the need for vaccines that induce durable sterilizing immunity. Here we optimized regimens for chemoprophylaxis vaccination (CVac), for which aseptic, purified, cryopreserved, infectious Plasmodium falciparum sporozoites (PfSPZ) were inoculated under prophylactic cover with pyrimethamine (PYR) (Sanaria PfSPZ-CVac(PYR)) or chloroquine (CQ) (PfSPZ-CVac(CQ))-which kill liver-stage and blood-stage parasites, respectively-and we assessed vaccine efficacy against homologous (that is, the same strain as the vaccine) and heterologous (a different strain) controlled human malaria infection (CHMI) three months after immunization ( https://clinicaltrials.gov/ , NCT02511054 and NCT03083847). We report that a fourfold increase in the dose of PfSPZ-CVac(PYR) from 5.12 × 104 to 2 × 105 PfSPZs transformed a minimal vaccine efficacy (low dose, two out of nine (22.2%) participants protected against homologous CHMI), to a high-level vaccine efficacy with seven out of eight (87.5%) individuals protected against homologous and seven out of nine (77.8%) protected against heterologous CHMI. Increased protection was associated with Vδ2 γδ T cell and antibody responses. At the higher dose, PfSPZ-CVac(CQ) protected six out of six (100%) participants against heterologous CHMI three months after immunization. All homologous (four out of four) and heterologous (eight out of eight) infectivity control participants showed parasitaemia. PfSPZ-CVac(CQ) and PfSPZ-CVac(PYR) induced a durable, sterile vaccine efficacy against a heterologous South American strain of P. falciparum, which has a genome and predicted CD8 T cell immunome that differs more strongly from the African vaccine strain than other analysed African P. falciparum strains.
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Affiliation(s)
- Agnes Mwakingwe-Omari
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Center for Vaccine Research, GlaxoSmithKline, Rockville, MD, USA
| | - Sara A Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jacquelyn Lane
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - David M Cook
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sahand Kalhori
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Charles Wyatt
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Aarti Kolluri
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Omely Marte-Salcedo
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Alemush Imeru
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Martha Nason
- Biostatistical Research Branch, National Institute of Allergy and Infectious Diseases, Rockville, MD, USA
| | - Lei K Ding
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Hope Decederfelt
- Clinical Center Pharmacy Department, National Institutes of Health, Bethesda, MD, USA
| | - Junhui Duan
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jacob Raiten
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Grace Lee
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jen C C Hume
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jihyun E Jeon
- Clinical Center Pharmacy Department, National Institutes of Health, Bethesda, MD, USA
| | - Ijeoma Ikpeama
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Natasha Kc
- Sanaria, Rockville, MD, USA
- Protein Potential, Rockville, MD, USA
| | | | | | | | | | | | - Charles Anderson
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sean C Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Seattle Malaria Clinical Trials Center, Fred Hutch Cancer Research Center, Seattle, WA, USA
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Sandra March
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sangeeta N Bhatia
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Cambridge, MA, USA
- Broad Institute, Cambridge, MA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
- Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | | | | | - B Kim Lee Sim
- Sanaria, Rockville, MD, USA
- Protein Potential, Rockville, MD, USA
| | | | - Irfan Zaidi
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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5
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Cai J, Chen S, Zhu F, Lu X, Liu T, Xu W. Whole-Killed Blood-Stage Vaccine: Is It Worthwhile to Further Develop It to Control Malaria? Front Microbiol 2021; 12:670775. [PMID: 33995336 PMCID: PMC8119638 DOI: 10.3389/fmicb.2021.670775] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/08/2021] [Indexed: 01/09/2023] Open
Abstract
Major challenges have been encountered regarding the development of highly efficient subunit malaria vaccines, and so whole-parasite vaccines have regained attention in recent years. The whole-killed blood-stage vaccine (WKV) is advantageous as it can be easily manufactured and efficiently induced protective immunity against a blood-stage challenge, as well as inducing cross-stage protection against both the liver and sexual-stages. However, it necessitates a high dose of parasitized red blood cell (pRBC) lysate for immunization, and this raises concerns regarding its safety and low immunogenicity. Knowledge of the major components of WKV that can induce or evade the host immune response, and the development of appropriate human-compatible adjuvants will greatly help to optimize the WKV. Therefore, we argue that the further development of the WKV is worthwhile to control and potentially eradicate malaria worldwide.
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Affiliation(s)
- Jingjing Cai
- College of Basic Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Suilin Chen
- College of Basic Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China
| | - Feng Zhu
- College of Basic Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China
| | - Xiao Lu
- Department of Thoracic Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Taiping Liu
- College of Basic Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China
| | - Wenyue Xu
- College of Basic Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China
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6
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Nahrendorf W, Ivens A, Spence PJ. Inducible mechanisms of disease tolerance provide an alternative strategy of acquired immunity to malaria. eLife 2021; 10:e63838. [PMID: 33752799 PMCID: PMC7987336 DOI: 10.7554/elife.63838] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/19/2021] [Indexed: 12/26/2022] Open
Abstract
Immunity to malaria is often considered slow to develop but this only applies to defense mechanisms that function to eliminate parasites (resistance). In contrast, immunity to severe disease can be acquired quickly and without the need for improved pathogen control (tolerance). Using Plasmodium chabaudi, we show that a single malaria episode is sufficient to induce host adaptations that can minimise inflammation, prevent tissue damage and avert endothelium activation, a hallmark of severe disease. Importantly, monocytes are functionally reprogrammed to prevent their differentiation into inflammatory macrophages and instead promote mechanisms of stress tolerance to protect their niche. This alternative fate is not underpinned by epigenetic reprogramming of bone marrow progenitors but appears to be imprinted within the remodelled spleen. Crucially, all of these adaptations operate independently of pathogen load and limit the damage caused by malaria parasites in subsequent infections. Acquired immunity to malaria therefore prioritises host fitness over pathogen clearance.
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Affiliation(s)
- Wiebke Nahrendorf
- Institute of Immunology and Infection Research, University of EdinburghEdinburghUnited Kingdom
| | - Alasdair Ivens
- Institute of Immunology and Infection Research, University of EdinburghEdinburghUnited Kingdom
- Centre for Immunity, Infection and Evolution, University of EdinburghEdinburghUnited Kingdom
| | - Philip J Spence
- Institute of Immunology and Infection Research, University of EdinburghEdinburghUnited Kingdom
- Centre for Immunity, Infection and Evolution, University of EdinburghEdinburghUnited Kingdom
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7
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Nevagi RJ, Good MF, Stanisic DI. Plasmodium infection and drug cure for malaria vaccine development. Expert Rev Vaccines 2021; 20:163-183. [PMID: 33428505 DOI: 10.1080/14760584.2021.1874923] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Introduction: Despite decades of research into the development of a vaccine to combat the malaria parasite, a highly efficacious malaria vaccine is not yet available. Different whole parasite-based vaccine approaches, including deliberate Plasmodium infection and drug cure (IDC), have been evaluated in pre-clinical and early phase clinical trials. The advantage of whole parasite vaccines is that they induce immune responses against multiple parasite antigens, thus lowering the impact of antigenic diversity. Deliberate Plasmodium IDC, as a vaccine approach, involves administering infectious, live parasites in combination with an anti-malarial drug, which controls the infection and enables induction of protective immune responses.
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Affiliation(s)
- Reshma J Nevagi
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia
| | - Michael F Good
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia
| | - Danielle I Stanisic
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia
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8
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Abuga KM, Jones-Warner W, Hafalla JCR. Immune responses to malaria pre-erythrocytic stages: Implications for vaccine development. Parasite Immunol 2020; 43:e12795. [PMID: 32981095 PMCID: PMC7612353 DOI: 10.1111/pim.12795] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 08/26/2020] [Accepted: 09/14/2020] [Indexed: 12/16/2022]
Abstract
Radiation-attenuated sporozoites induce sterilizing immunity and remain the 'gold standard' for malaria vaccine development. Despite practical challenges in translating these whole sporozoite vaccines to large-scale intervention programmes, they have provided an excellent platform to dissect the immune responses to malaria pre-erythrocytic (PE) stages, comprising both sporozoites and exoerythrocytic forms. Investigations in rodent models have provided insights that led to the clinical translation of various vaccine candidates-including RTS,S/AS01, the most advanced candidate currently in a trial implementation programme in three African countries. With advances in immunology, transcriptomics and proteomics, and application of lessons from past failures, an effective, long-lasting and wide-scale malaria PE vaccine remains feasible. This review underscores the progress in PE vaccine development, focusing on our understanding of host-parasite immunological crosstalk in the tissue environments of the skin and the liver. We highlight possible gaps in the current knowledge of PE immunity that can impact future malaria vaccine development efforts.
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Affiliation(s)
- Kelvin Mokaya Abuga
- Department of Infection Biology, Faculty of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Department of Epidemiology and Demography, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - William Jones-Warner
- Department of Infection Biology, Faculty of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Julius Clemence R Hafalla
- Department of Infection Biology, Faculty of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK
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9
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Kamiya T, Greischar MA, Schneider DS, Mideo N. Uncovering drivers of dose-dependence and individual variation in malaria infection outcomes. PLoS Comput Biol 2020; 16:e1008211. [PMID: 33031367 PMCID: PMC7544130 DOI: 10.1371/journal.pcbi.1008211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 07/31/2020] [Indexed: 01/01/2023] Open
Abstract
To understand why some hosts get sicker than others from the same type of infection, it is essential to explain how key processes, such as host responses to infection and parasite growth, are influenced by various biotic and abiotic factors. In many disease systems, the initial infection dose impacts host morbidity and mortality. To explore drivers of dose-dependence and individual variation in infection outcomes, we devised a mathematical model of malaria infection that allowed host and parasite traits to be linear functions (reaction norms) of the initial dose. We fitted the model, using a hierarchical Bayesian approach, to experimental time-series data of acute Plasmodium chabaudi infection across doses spanning seven orders of magnitude. We found evidence for both dose-dependent facilitation and debilitation of host responses. Most importantly, increasing dose reduced the strength of activation of indiscriminate host clearance of red blood cells while increasing the half-life of that response, leading to the maximal response at an intermediate dose. We also explored the causes of diverse infection outcomes across replicate mice receiving the same dose. Besides random noise in the injected dose, we found variation in peak parasite load was due to unobserved individual variation in host responses to clear infected cells. Individual variation in anaemia was likely driven by random variation in parasite burst size, which is linked to the rate of host cells lost to malaria infection. General host vigour in the absence of infection was also correlated with host health during malaria infection. Our work demonstrates that the reaction norm approach provides a useful quantitative framework for examining the impact of a continuous external factor on within-host infection processes.
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Affiliation(s)
- Tsukushi Kamiya
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Megan A. Greischar
- Department of Ecology Evolutionary Biology, Cornell University, United States of America
| | - David S. Schneider
- Program in Immunology, Stanford University, Stanford, California, United States of America
- Department of Microbiology and Immunology, Stanford University, Stanford, California, United States of America
| | - Nicole Mideo
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
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10
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Controlled Infection Immunization Using Delayed Death Drug Treatment Elicits Protective Immune Responses to Blood-Stage Malaria Parasites. Infect Immun 2018; 87:IAI.00587-18. [PMID: 30323025 PMCID: PMC6300636 DOI: 10.1128/iai.00587-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 09/23/2018] [Indexed: 01/27/2023] Open
Abstract
Naturally acquired immunity to malaria is robust and protective against all strains of the same species of Plasmodium. This develops as a result of repeated natural infection, taking several years to develop. Naturally acquired immunity to malaria is robust and protective against all strains of the same species of Plasmodium. This develops as a result of repeated natural infection, taking several years to develop. Evidence suggests that apoptosis of immune lymphocytes due to uncontrolled parasite growth contributes to the slow acquisition of immunity. To hasten and augment the development of natural immunity, we studied controlled infection immunization (CII) using low-dose exposure to different parasite species (Plasmodium chabaudi, P. yoelii, or P. falciparum) in two rodent systems (BALB/c and C57BL/6 mice) and in human volunteers, with drug therapy commencing at the time of initiation of infection. CIIs with infected erythrocytes and in conjunction with doxycycline or azithromycin, which are delayed death drugs targeting the parasite’s apicoplast, allowed extended exposure to parasites at low levels. In turn, this induced strong protection against homologous challenge in all immunized mice. We show that P. chabaudi/P. yoelii infection initiated at the commencement of doxycycline therapy leads to cellular or antibody-mediated protective immune responses in mice, with a broad Th1 cytokine response providing the best correlate of protection against homologous and heterologous species of Plasmodium. P. falciparum CII with doxycycline was additionally tested in a pilot clinical study (n = 4) and was found to be well tolerated and immunogenic, with immunological studies primarily detecting increased cell-associated immune responses. Furthermore, we report that a single dose of the longer-acting drug, azithromycin, given to mice (n = 5) as a single subcutaneous treatment at the initiation of infection controlled P. yoelii infection and protected all mice against subsequent challenge.
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11
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Cockburn IA, Seder RA. Malaria prevention: from immunological concepts to effective vaccines and protective antibodies. Nat Immunol 2018; 19:1199-1211. [PMID: 30333613 DOI: 10.1038/s41590-018-0228-6] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/31/2018] [Indexed: 02/08/2023]
Abstract
Development of a malaria vaccine remains a critical priority to decrease clinical disease and mortality and facilitate eradication. Accordingly, RTS,S, a protein-subunit vaccine, has completed phase III clinical trials and confers ~30% protection against clinical infection over 4 years. Whole-attenuated-sporozoite and viral-subunit vaccines induce between 20% and 100% protection against controlled human malaria infection, but there is limited published evidence to date for durable, high-level efficacy (>50%) against natural exposure. Importantly, fundamental scientific advances related to the potency, durability, breadth and location of immune responses will be required for improving vaccine efficacy with these and other vaccine approaches. In this Review, we focus on the current understanding of immunological mechanisms of protection from animal models and human vaccine studies, and on how these data should inform the development of next-generation vaccines. Furthermore, we introduce the concept of using passive immunization with monoclonal antibodies as a new approach to prevent and eliminate malaria.
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Affiliation(s)
- Ian A Cockburn
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA.
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12
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Majji S, Wijayalath W, Shashikumar S, Brumeanu TD, Casares S. Humanized DRAGA mice immunized with Plasmodium falciparum sporozoites and chloroquine elicit protective pre-erythrocytic immunity. Malar J 2018. [PMID: 29540197 PMCID: PMC5853061 DOI: 10.1186/s12936-018-2264-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background Human-immune-system humanized mouse models can bridge the gap between humans and conventional mice for testing human vaccines. The HLA-expressing humanized DRAGA (HLA-A2.HLA-DR4.Rag1KO.IL2RγcKO.NOD) mice reconstitute a functional human-immune-system and sustain the complete life cycle of Plasmodium falciparum. Herein, the DRAGA mice were investigated for immune responses following immunization with live P. falciparum sporozoites under chloroquine chemoprophylaxis (CPS-CQ), an immunization approach that showed in human trials to confer pre-erythrocytic immunity. Results The CPS-CQ immunized DRAGA mice (i) elicited human CD4 and CD8 T cell responses to antigens expressed by P. falciparum sporozoites (Pfspz) and by the infected-red blood cells (iRBC). The Pfspz-specific human T cell responses were found to be systemic (spleen and liver), whereas the iRBCs-specific human T cell responses were more localized to the liver, (ii) elicited stronger antibody responses to the Pfspz than to the iRBCs, and (iii) they were protected against challenge with infectious Pfspz but not against challenge with iRBCs. Conclusions The DRAGA mice represent a new pre-clinical model to investigate the immunogenicity and protective efficacy of P. falciparum malaria vaccine candidates. Electronic supplementary material The online version of this article (10.1186/s12936-018-2264-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sai Majji
- US Military Malaria Vaccine Program, Naval Medical Research Center/Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Wathsala Wijayalath
- US Military Malaria Vaccine Program, Naval Medical Research Center/Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Soumya Shashikumar
- US Military Malaria Vaccine Program, Naval Medical Research Center/Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Teodor D Brumeanu
- Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, MD, USA
| | - Sofia Casares
- US Military Malaria Vaccine Program, Naval Medical Research Center/Walter Reed Army Institute of Research, Silver Spring, MD, USA. .,Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, MD, USA.
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13
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Protection from experimental cerebral malaria with a single intravenous or subcutaneous whole-parasite immunization. Sci Rep 2018; 8:3085. [PMID: 29449638 PMCID: PMC5814423 DOI: 10.1038/s41598-018-21551-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 02/05/2018] [Indexed: 12/20/2022] Open
Abstract
Cerebral malaria is a life-threatening complication of Plasmodia infection and a major cause of child mortality in Sub-Saharan Africa. We report that protection from experimental cerebral malaria in the rodent model is obtained by a single intravenous or subcutaneous whole-parasite immunization. Whole-parasite immunization with radiation-attenuated sporozoites was equally protective as immunization with non-attenuated sporozoites under chemoprophylaxis. Both immunization regimens delayed the development of blood-stage parasites, but differences in cellular and humoral immune mechanisms were observed. Single-dose whole-parasite vaccination might serve as a relatively simple and feasible immunization approach to prevent life-threatening cerebral malaria.
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14
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Exploiting the apicoplast: apicoplast-targeting drugs and malaria vaccine development. Microbes Infect 2017; 20:477-483. [PMID: 29287981 DOI: 10.1016/j.micinf.2017.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/12/2017] [Indexed: 02/04/2023]
Abstract
The apicoplast, a relic plastid found in most Apicomplexan parasites, is a notable drug target. Certain antibiotics elicit a delayed death phenotype by targeting this organelle. Here, we review apicoplast-targeting drugs and their targets, particularly those that cause delayed death, and highlight its potential uses in malaria vaccine development.
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15
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Healer J, Cowman AF, Kaslow DC, Birkett AJ. Vaccines to Accelerate Malaria Elimination and Eventual Eradication. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a025627. [PMID: 28490535 DOI: 10.1101/cshperspect.a025627] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Remarkable progress has been made in coordinated malaria control efforts with substantial reductions in malaria-associated deaths and morbidity achieved through mass administration of drugs and vector control measures including distribution of long-lasting insecticide-impregnated bednets and indoor residual spraying. However, emerging resistance poses a significant threat to the sustainability of these interventions. In this light, the malaria research community has been charged with the development of a highly efficacious vaccine to complement existing malaria elimination measures. As the past 40 years of investment in this goal attests, this is no small feat. The malaria parasite is a highly complex organism, exquisitely adapted for survival under hostile conditions within human and mosquito hosts. Here we review current vaccine strategies to accelerate elimination and the potential for novel and innovative approaches to vaccine design through a better understanding of the host-parasite interaction.
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Affiliation(s)
- Julie Healer
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
| | - Alan F Cowman
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
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16
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Abstract
Malaria vaccine development has been dominated by the subunit approach; however, many subunit vaccine candidates have had limited efficacy in settings of malaria endemicity. As our search for an efficacious malaria vaccine continues, the development of a whole-organism vaccine is now receiving much scrutiny. One strategy currently being explored in the development of a whole-organism vaccine involves chemical attenuation of the malaria parasite. In vivo and in vitro chemical attenuation of both liver-stage and blood-stage Plasmodium parasites has been investigated. Here, we discuss both approaches of chemical attenuation in the development of a whole-organism vaccine against malaria.
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17
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Pichyangkul S, Spring MD, Yongvanitchit K, Kum-Arb U, Limsalakpetch A, Im-Erbsin R, Ubalee R, Vanachayangkul P, Remarque EJ, Angov E, Smith PL, Saunders DL. Chemoprophylaxis with sporozoite immunization in P. knowlesi rhesus monkeys confers protection and elicits sporozoite-specific memory T cells in the liver. PLoS One 2017; 12:e0171826. [PMID: 28182750 PMCID: PMC5300246 DOI: 10.1371/journal.pone.0171826] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 01/26/2017] [Indexed: 12/11/2022] Open
Abstract
Whole malaria sporozoite vaccine regimens are promising new strategies, and some candidates have demonstrated high rates of durable clinical protection associated with memory T cell responses. Little is known about the anatomical distribution of memory T cells following whole sporozoite vaccines, and immunization of nonhuman primates can be used as a relevant model for humans. We conducted a chemoprophylaxis with sporozoite (CPS) immunization in P. knowlesi rhesus monkeys and challenged via mosquito bites. Half of CPS immunized animals developed complete protection, with a marked delay in parasitemia demonstrated in the other half. Antibody responses to whole sporozoites, CSP, and AMA1, but not CelTOS were detected. Peripheral blood T cell responses to whole sporozoites, but not CSP and AMA1 peptides were observed. Unlike peripheral blood, there was a high frequency of sporozoite-specific memory T cells observed in the liver and bone marrow. Interestingly, sporozoite-specific CD4+ and CD8+ memory T cells in the liver highly expressed chemokine receptors CCR5 and CXCR6, both of which are known for liver sinusoid homing. The majority of liver sporozoite-specific memory T cells expressed CD69, a phenotypic marker of tissue-resident memory (TRM) cells, which are well positioned to rapidly control liver-stage infection. Vaccine strategies that aim to elicit large number of liver TRM cells may efficiently increase the efficacy and durability of response against pre-erythrocytic parasites.
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Affiliation(s)
- Sathit Pichyangkul
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
- * E-mail:
| | - Michele D. Spring
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Kosol Yongvanitchit
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Utaiwan Kum-Arb
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | - Rawiwan Im-Erbsin
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Ratawan Ubalee
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | | | - Evelina Angov
- Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Philip L. Smith
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - David L. Saunders
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
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18
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Lu X, Liu T, Zhu F, Chen L, Xu W. A whole-killed, blood-stage lysate vaccine protects against the malaria liver stage. Parasite Immunol 2016; 39. [PMID: 27635936 DOI: 10.1111/pim.12386] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/12/2016] [Indexed: 11/30/2022]
Abstract
Although the attenuated sporozoite is the most efficient vaccine to prevent infection with the malaria parasite, the limitation of a source of sterile sporozoites greatly hampers its application. In this study, we found that the whole-killed, blood-stage lysate vaccine could confer protection against the blood stage as well as the liver stage. Although the protective immunity induced by the whole-organism vaccine against the blood stage is dependent on parasite-specific CD4+ T-cell responses and antibodies, in mice immunized with the whole-killed, blood-stage lysate vaccine, CD8+ , but not CD4+ effector T-cell responses greatly contributed to protection against the liver stage. Thus, our data suggested that the whole-killed, blood-stage lysate vaccine could be an alternative promising strategy to prevent malaria infection and to reduce the morbidity and mortality of patients with malaria.
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Affiliation(s)
- X Lu
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China.,Department of Microbiology, Third Military Medical University, Chongqing, China
| | - T Liu
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China
| | - F Zhu
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China
| | - L Chen
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China
| | - W Xu
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China
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19
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Hobbs CV, Anderson C, Neal J, Sahu T, Conteh S, Voza T, Langhorne J, Borkowsky W, Duffy PE. Trimethoprim-Sulfamethoxazole Prophylaxis During Live Malaria Sporozoite Immunization Induces Long-Lived, Homologous, and Heterologous Protective Immunity Against Sporozoite Challenge. J Infect Dis 2016; 215:122-130. [PMID: 28077589 DOI: 10.1093/infdis/jiw482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/30/2016] [Indexed: 11/12/2022] Open
Abstract
Trimethoprim-sulfamethoxazole (TMP-SMX) is widely used in malaria-endemic areas in human immunodeficiency virus (HIV)-infected children and HIV-uninfected, HIV-exposed children as opportunistic infection prophylaxis. Despite the known effects that TMP-SMX has in reducing clinical malaria, its impact on development of malaria-specific immunity in these children remains poorly understood. Using rodent malaria models, we previously showed that TMP-SMX, at prophylactic doses, can arrest liver stage development of malaria parasites and speculated that TMP-SMX prophylaxis during repeated malaria exposures would induce protective long-lived sterile immunity targeting pre-erythrocytic stage parasites in mice. Using the same models, we now demonstrate that repeated exposures to malaria parasites during TMP-SMX administration induces stage-specific and long-lived pre-erythrocytic protective anti-malarial immunity, mediated primarily by CD8+ T-cells. Given the HIV infection and malaria coepidemic in sub-Saharan Africa, clinical studies aimed at determining the optimum duration of TMP-SMX prophylaxis in HIV-infected or HIV-exposed children must account for the potential anti-infection immunity effect of TMP-SMX prophylaxis.
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Affiliation(s)
- Charlotte V Hobbs
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland.,Division of Infectious Diseases, Department of Pediatrics.,Department of Microbiology, Batson Children's Hospital, University of Mississippi Medical Center, Jackson.,Division of Infectious Disease and Immunology, Department of Pediatrics, New York University School of Medicine
| | - Charles Anderson
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Tejram Sahu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Solomon Conteh
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Tatiana Voza
- Biological Sciences Department, New York City College of Technology, City University of New York
| | - Jean Langhorne
- Mill Hill Laboratory, Francis Crick Institute, London, United Kingdom
| | - William Borkowsky
- Division of Infectious Disease and Immunology, Department of Pediatrics, New York University School of Medicine
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
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20
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Chemically Attenuated Blood-Stage Plasmodium yoelii Parasites Induce Long-Lived and Strain-Transcending Protection. Infect Immun 2016; 84:2274-2288. [PMID: 27245410 PMCID: PMC4962623 DOI: 10.1128/iai.00157-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 05/20/2016] [Indexed: 11/30/2022] Open
Abstract
The development of a vaccine is essential for the elimination of malaria. However, despite many years of effort, a successful vaccine has not been achieved. Most subunit vaccine candidates tested in clinical trials have provided limited efficacy, and thus attenuated whole-parasite vaccines are now receiving close scrutiny. Here, we test chemically attenuated Plasmodium yoelii 17X and demonstrate significant protection following homologous and heterologous blood-stage challenge. Protection against blood-stage infection persisted for at least 9 months. Activation of both CD4+ and CD8+ T cells was shown after vaccination; however, in vivo studies demonstrated a pivotal role for both CD4+ T cells and B cells since the absence of either cell type led to loss of vaccine-induced protection. In spite of significant activation of circulating CD8+ T cells, liver-stage immunity was not evident. Neither did vaccine-induced CD8+ T cells contribute to blood-stage protection; rather, these cells contributed to pathogenesis, since all vaccinated mice depleted of both CD4+ and CD8+ T cells survived a challenge infection. This study provides critical insight into whole-parasite vaccine-induced immunity and strong support for testing whole-parasite vaccines in humans.
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21
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Jagannathan P, Bowen K, Nankya F, McIntyre TI, Auma A, Wamala S, Sikyomu E, Naluwu K, Nalubega M, Boyle MJ, Farrington LA, Bigira V, Kapisi J, Aweeka F, Greenhouse B, Kamya M, Dorsey G, Feeney ME. Effective Antimalarial Chemoprevention in Childhood Enhances the Quality of CD4+ T Cells and Limits Their Production of Immunoregulatory Interleukin 10. J Infect Dis 2016; 214:329-38. [PMID: 27067196 DOI: 10.1093/infdis/jiw147] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 04/04/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Experimental inoculation of viable Plasmodium falciparum sporozoites administered with chemoprevention targeting blood-stage parasites results in protective immunity. It is unclear whether chemoprevention similarly enhances immunity following natural exposure to malaria. METHODS We assessed P. falciparum-specific T-cell responses among Ugandan children who were randomly assigned to receive monthly dihydroartemisinin-piperaquine (DP; n = 87) or no chemoprevention (n = 90) from 6 to 24 months of age, with pharmacologic assessments for adherence, and then clinically followed for an additional year. RESULTS During the intervention, monthly DP reduced malaria episodes by 55% overall (P < .001) and by 97% among children who were highly adherent to DP (P < .001). In the year after the cessation of chemoprevention, children who were highly adherent to DP had a 55% reduction in malaria incidence as compared to children given no chemoprevention (P = .004). Children randomly assigned to receive DP had higher frequencies of blood-stage specific CD4(+) T cells coproducing interleukin-2 and tumor necrosis factor α (P = .003), which were associated with protection from subsequent clinical malaria and parasitemia, and fewer blood-stage specific CD4(+) T cells coproducing interleukin-10 and interferon γ (P = .001), which were associated with increased risk of malaria. CONCLUSIONS In this setting, effective antimalarial chemoprevention fostered the development of CD4(+) T cells that coproduced interleukin 2 and tumor necrosis factor α and were associated with prospective protection, while limiting CD4(+) T-cell production of the immunoregulatory cytokine IL-10.
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Affiliation(s)
| | | | | | | | - Ann Auma
- Infectious Diseases Research Collaboration
| | | | | | | | | | - Michelle J Boyle
- Department of Medicine, San Francisco General Hospital Center for Biomedical Research, The Burnet Institute, Melbourne, Australia
| | | | | | | | | | | | - Moses Kamya
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital
| | - Margaret E Feeney
- Department of Medicine, San Francisco General Hospital Department of Pediatrics, University of California-San Francisco
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22
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Bijker EM, Borrmann S, Kappe SH, Mordmüller B, Sack BK, Khan SM. Novel approaches to whole sporozoite vaccination against malaria. Vaccine 2015; 33:7462-8. [PMID: 26469716 PMCID: PMC6858867 DOI: 10.1016/j.vaccine.2015.09.095] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 08/22/2015] [Accepted: 09/22/2015] [Indexed: 12/15/2022]
Abstract
The parasitic disease malaria threatens more than 3 billion people worldwide, resulting in more than 200 million clinical cases and almost 600,000 deaths annually. Vaccines remain crucial for prevention and ultimately eradication of infectious diseases and, for malaria, whole sporozoite based immunization has been shown to be the most effective in experimental settings. In addition to immunization with radiation-attenuated sporozoites, chemoprophylaxis and sporozoites (CPS) is a highly efficient strategy to induce sterile protection in humans. Genetically attenuated parasites (GAP) have demonstrated significant protection in rodent studies, and are now being advanced into clinical testing. This review describes the existing pre-clinical and clinical data on CPS and GAP, discusses recent developments and examines how to transform these immunization approaches into vaccine candidates for clinical development.
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Affiliation(s)
- Else M Bijker
- Radboud University Medical Center, Department of Medical Microbiology, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, University of Tübingen, Tübingen, Germany; Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Stefan H Kappe
- Seattle Biomedical Research Institute, Seattle, WA, USA; Department of Global Health, University of Washington, Seattle, WA, USA
| | - Benjamin Mordmüller
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, University of Tübingen, Tübingen, Germany; Centre de Recherches Médicales de Lambaréné, Alberts Schweitzer Hospital, BP 118 Lambaréné, Gabon
| | | | - Shahid M Khan
- Leiden University Medical Center, Department of Parasitology, PO Box 9600, 2300 RC Leiden, The Netherlands
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23
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Nahrendorf W, Scholzen A, Sauerwein RW, Langhorne J. Cross-stage immunity for malaria vaccine development. Vaccine 2015; 33:7513-7. [PMID: 26469724 PMCID: PMC4687527 DOI: 10.1016/j.vaccine.2015.09.098] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 09/11/2015] [Accepted: 09/28/2015] [Indexed: 11/17/2022]
Abstract
A vaccine against malaria is urgently needed for control and eventual eradication. Different approaches are pursued to induce either sterile immunity directed against pre-erythrocytic parasites or to mimic naturally acquired immunity by controlling blood-stage parasite densities and disease severity. Pre-erythrocytic and blood-stage malaria vaccines are often seen as opposing tactics, but it is likely that they have to be combined into a multi-stage malaria vaccine to be optimally safe and effective. Since many antigenic targets are shared between liver- and blood-stage parasites, malaria vaccines have the potential to elicit cross-stage protection with immune mechanisms against both stages complementing and enhancing each other. Here we discuss evidence from pre-erythrocytic and blood-stage subunit and whole parasite vaccination approaches that show that protection against malaria is not necessarily stage-specific. Parasites arresting at late liver-stages especially, can induce powerful blood-stage immunity, and similarly exposure to blood-stage parasites can afford pre-erythrocytic immunity. The incorporation of a blood-stage component into a multi-stage malaria vaccine would hence not only combat breakthrough infections in the blood should the pre-erythrocytic component fail to induce sterile protection, but would also actively enhance the pre-erythrocytic potency of this vaccine. We therefore advocate that future studies should concentrate on the identification of cross-stage protective malaria antigens, which can empower multi-stage malaria vaccine development.
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Affiliation(s)
- Wiebke Nahrendorf
- Mill Hill Laboratory, The Francis Crick Institute, London, United Kingdom; Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Anja Scholzen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Jean Langhorne
- Mill Hill Laboratory, The Francis Crick Institute, London, United Kingdom.
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