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Thawornpan P, Nicholas J, Malee C, Kochayoo P, Wangriatisak K, Tianpothong P, Ntumngia FB, J. Barnes S, H. Adams J, Chootong P. Longitudinal analysis of antibody responses to Plasmodium vivax sporozoite antigens following natural infection. PLoS Negl Trop Dis 2024; 18:e0011907. [PMID: 38277340 PMCID: PMC10817200 DOI: 10.1371/journal.pntd.0011907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 01/08/2024] [Indexed: 01/28/2024] Open
Abstract
BACKGROUND P. vivax malaria is a major global health burden hindering social and economic development throughout many tropical and sub-tropical countries. Pre-erythrocytic (PE) vaccines emerge as an attractive approach for the control and elimination of malaria infection. Therefore, evaluating the magnitude, longevity and prevalence of naturally acquired IgG antibody responses against PE candidate antigens is useful for vaccine design. METHODOLOGY/PRINCIPAL FINDINGS The antigenicity of five recombinant PE antigens (PvCSP-VK210, PvSSP3, PvM2-MAEBL, PvCelTOS and PvSPECT1) was evaluated in plasma samples from individuals residing in low transmission areas in Thailand (Ranong and Chumphon Provinces). The samples were collected at the time of acute vivax malaria and 90, 270 and 360 days later. The prevalence, magnitude and longevity of total IgG and IgG subclasses were determined for each antigen using the longitudinal data. Our results showed that seropositivity of all tested PE antigens was detected during infection in at least some subjects; anti-PvCSP-VK210 and anti-PvCelTOS antibodies were the most frequent. Titers of these antibodies declined during the year of follow up, but notably seropositivity persisted. Among seropositive subjects at post-infection, high number of subjects possessed antibodies against PvCSP-VK210. Anti-PvSSP3 antibody responses had the longest half-life. IgG subclass profiling showed that the predominant subclasses were IgG1 and IgG3 (cytophilic antibodies), tending to remain detectable for at least 360 days after infection. CONCLUSIONS/SIGNIFICANCE The present study demonstrated the magnitude and longevity of serological responses to multiple PE antigens of P. vivax after natural infection. This knowledge could contribute to the design of an effective P. vivax vaccine.
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Affiliation(s)
- Pongsakorn Thawornpan
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Justin Nicholas
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Chayapat Malee
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Piyawan Kochayoo
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Kittikorn Wangriatisak
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Pachara Tianpothong
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Francis Babila Ntumngia
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Samantha J. Barnes
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - John H. Adams
- Center for Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Patchanee Chootong
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
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2
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Live attenuated vaccines, a favorable strategy to provide long-term immunity against protozoan diseases. Trends Parasitol 2021; 38:316-334. [PMID: 34896016 DOI: 10.1016/j.pt.2021.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 12/25/2022]
Abstract
The control of diseases caused by protozoan parasites is one of the United Nations' Sustainable Development Goals. In recent years much research effort has gone into developing a new generation of live attenuated vaccines (LAVs) against malaria, Chagas disease and leishmaniasis. However, there is a bottleneck related to their biosafety, production, and distribution that slows downs further development. The success of irradiated or genetically attenuated sporozoites against malaria, added to the first LAV against leishmaniasis to be evaluated in clinical trials, is indicative that the drawbacks of LAVs are gradually being overcome. However, whether persistence of LAVs is a prerequisite for sustained long-term immunity remains to be clarified, and the procedures necessary for clinical evaluation of vaccine candidates need to be standardized.
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3
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Alder A, Struck NS, Xu M, Johnson JW, Wang W, Pallant D, Cook MA, Rambow J, Lemcke S, Gilberger TW, Wright GD. A non-reactive natural product precursor of the duocarmycin family has potent and selective antimalarial activity. Cell Chem Biol 2021; 29:840-853.e6. [PMID: 34710358 DOI: 10.1016/j.chembiol.2021.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/15/2021] [Accepted: 10/02/2021] [Indexed: 11/27/2022]
Abstract
We identify a selective nanomolar inhibitor of blood-stage malarial proliferation from a screen of microbial natural product extracts. The responsible compound, PDE-I2, is a precursor of the anticancer duocarmycin family that preserves the class's sequence-specific DNA binding but lacks its signature DNA alkylating cyclopropyl warhead. While less active than duocarmycin, PDE-I2 retains comparable antimalarial potency to chloroquine. Importantly, PDE-I2 is >1,000-fold less toxic to human cell lines than duocarmycin, with mitigated impacts on eukaryotic chromosome stability. PDE-I2 treatment induces severe defects in parasite nuclear segregation leading to impaired daughter cell formation during schizogony. Time-of-addition studies implicate parasite DNA metabolism as the target of PDE-I2, with defects observed in DNA replication and chromosome integrity. We find the effect of duocarmycin and PDE-I2 on parasites is phenotypically indistinguishable, indicating that the DNA binding specificity of duocarmycins is sufficient and the genotoxic cyclopropyl warhead is dispensable for the parasite-specific selectivity of this compound class.
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Affiliation(s)
- Arne Alder
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany
| | - Nicole S Struck
- Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada; German Centre for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Min Xu
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Jarrod W Johnson
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Wenliang Wang
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Daniel Pallant
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Michael A Cook
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Janis Rambow
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany
| | - Sarah Lemcke
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany.
| | - Gerard D Wright
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada.
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4
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Mitran CJ, Yanow SK. The Case for Exploiting Cross-Species Epitopes in Malaria Vaccine Design. Front Immunol 2020; 11:335. [PMID: 32174924 PMCID: PMC7056716 DOI: 10.3389/fimmu.2020.00335] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/10/2020] [Indexed: 12/21/2022] Open
Abstract
The infection dynamics between different species of Plasmodium that infect the same human host can both suppress and exacerbate disease. This could arise from inter-parasite interactions, such as competition, from immune regulation, or both. The occurrence of protective, cross-species (heterologous) immunity is an unlikely event, especially considering that strain-transcending immunity within a species is only partial despite lifelong exposure to that species. Here we review the literature in humans and animal models to identify the contexts where heterologous immunity can arise, and which antigens may be involved. From the perspective of vaccine design, understanding the mechanisms by which exposure to an antigen from one species can elicit a protective response to another species offers an alternative strategy to conventional approaches that focus on immunodominant antigens within a single species. The underlying hypothesis is that certain epitopes are conserved across evolution, in sequence or in structure, and shared in antigens from different species. Vaccines that focus on conserved epitopes may overcome the challenges posed by polymorphic immunodominant antigens; but to uncover these epitopes requires approaches that consider the evolutionary history of protein families across species. The key question for vaccinologists will be whether vaccines that express these epitopes can elicit immune responses that are functional and contribute to protection against Plasmodium parasites.
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Affiliation(s)
| | - Stephanie K. Yanow
- School of Public Health, University of Alberta, Edmonton, AB, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
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5
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[Development of malaria vaccines-state of the art]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2019; 63:45-55. [PMID: 31828371 PMCID: PMC7223738 DOI: 10.1007/s00103-019-03070-1] [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] [Indexed: 11/28/2022]
Abstract
Weltweit leben 3,1 Mrd. Menschen in Gebieten, in denen Malaria endemisch ist (Tropen, Subtropen). Jährlich erkranken etwa 200 Mio. Menschen, ca. 500.000 sterben daran. Betroffen sind vor allem Kinder. Um die Malaria zu kontrollieren und schlussendlich jegliche Neuinfektion zu verhindern, ist die Entwicklung wirksamer Impfstoffe von großer Bedeutung. In diesem Beitrag werden zunächst Hintergrundinformationen zur Geschichte der Impfstoffentwicklung, zur Malariaerkrankung und zu den Möglichkeiten der Therapie und Ausbreitungskontrolle gegeben. Der Hauptteil widmet sich dem aktuellen Forschungsstand zu Impfstoffen gegen den Erreger Plasmodium falciparum, gefolgt von einer ausführlichen Diskussion. Malaria ist eine parasitäre Infektionskrankheit, die von Einzellern, sog. Plasmodien, verursacht wird. Es werden 5 humanpathogene Spezies unterschieden, von denen P. falciparum über 99 % der Erkrankungen in Afrika verursacht. Überträger (Vektor) ist die Anophelesmücke. Plasmodium bietet innerhalb seines Lebenszyklus verschiedene Ansatzpunkte für die Wirkung von Impfstoffen. Von den insgesamt ca. 70 Impfstoffkandidaten sind die präerythrozytären Impfstoffe, die in den Leberzyklus des Parasiten eingreifen, aktuell am weitesten entwickelt. Die von der Weltgesundheitsorganisation (WHO) angestrebte Wirksamkeit von mindestens 75 % wurde aber längst nicht erreicht. Mit RTS,S/AS01 wird derzeit erstmals ein mäßig wirksamer Impfstoff großflächig eingesetzt. Schon jetzt ist offensichtlich, dass die Malaria nur im Zusammenspiel mit anderen Maßnahmen eingedämmt werden kann. Expositionsprophylaxe mit imprägnierten Moskitonetzen, der Einsatz von Insektiziden mit Residualeffekt in Innenräumen (Indoor Residual Spraying), die Vernichtung von Moskitobrutplätzen und schnelle Diagnose und Therapie der Erkrankung sind hier wichtige Elemente ebenso wie eine funktionierende Gesundheitsversorgung, die in den von Armut geprägten Gebieten oft nicht gewährleistet ist.
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6
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Good MF, Stanisic DI. Whole parasite vaccines for the asexual blood stages ofPlasmodium. Immunol Rev 2019; 293:270-282. [DOI: 10.1111/imr.12819] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 08/27/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Michael F. Good
- Institute for Glycomics Griffith University Gold Coast Qld. Australia
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7
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Narula AK, Azad CS, Nainwal LM. New dimensions in the field of antimalarial research against malaria resurgence. Eur J Med Chem 2019; 181:111353. [DOI: 10.1016/j.ejmech.2019.05.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/16/2019] [Accepted: 05/15/2019] [Indexed: 12/20/2022]
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8
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Vom Steeg LG, Flores-Garcia Y, Zavala F, Klein SL. Irradiated sporozoite vaccination induces sex-specific immune responses and protection against malaria in mice. Vaccine 2019; 37:4468-4476. [PMID: 31262583 PMCID: PMC7862922 DOI: 10.1016/j.vaccine.2019.06.075] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/23/2019] [Accepted: 06/24/2019] [Indexed: 10/26/2022]
Abstract
In both preclinical animal studies and human clinical trials, adult females tend to develop greater adaptive immune responses than males following receipt of either viral or bacterial vaccines. While there is currently no approved malaria vaccine, several anti-sporozoite vaccines, including RTS,S/AS01 and attenuated sporozoite vaccines, are in development, but the impact of sex and age on their efficacy remains undefined. To examine sex differences in the efficacy of anti-sporozoite stage malaria vaccination, adult (10 weeks of age) or juvenile (11 days of age) male and female C3H mice were twice vaccinated with irradiated transgenic Plasmodium berghei sporozoites expressing the P. falciparum circumsporozoite (CSP) protein and 45 days post boost vaccination, mice were challenged with transgenic P. berghei via mosquito bite or intradermal challenge. Immunization with irradiated sporozoites resulted in greater protection against challenge in adult females, which was associated with greater anti-CSP antibody production and avidity, as well as greater hepatic, but not splenic, CD8+ T cell IFNƴ production in adult females than adult males. No sex differences in adaptive immune responses or protection were observed in mice vaccinated prior to puberty, suggesting a role for sex steroid hormones. Depletion of testosterone in males increased, whereas rescue of testosterone decreased, anti-CSP antibody production, the number of antigen-specific CD8+ T cells isolated from the liver, and protection following parasite challenge. Conversely, depletion of sex steroids in female mice did not alter vaccine-induced responses or protection following challenge. These data suggest that elevated testosterone concentrations in males reduce adaptive immunity and contribute to sex differences in malaria vaccine efficacy.
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Affiliation(s)
- Landon G Vom Steeg
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, MD, USA
| | - Yevel Flores-Garcia
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, MD, USA
| | - Fidel Zavala
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, MD, USA
| | - Sabra L Klein
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, MD, USA; Department of Biochemistry and Molecular Biology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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9
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Goh YS, McGuire D, Rénia L. Vaccination With Sporozoites: Models and Correlates of Protection. Front Immunol 2019; 10:1227. [PMID: 31231377 PMCID: PMC6560154 DOI: 10.3389/fimmu.2019.01227] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 05/14/2019] [Indexed: 12/14/2022] Open
Abstract
Despite continuous efforts, the century-old goal of eradicating malaria still remains. Multiple control interventions need to be in place simultaneously to achieve this goal. In addition to effective control measures, drug therapies and insecticides, vaccines are critical to reduce mortality and morbidity. Hence, there are numerous studies investigating various malaria vaccine candidates. Most of the malaria vaccine candidates are subunit vaccines. However, they have shown limited efficacy in Phase II and III studies. To date, only whole parasite formulations have been shown to induce sterile immunity in human. In this article, we review and discuss the recent developments in vaccination with sporozoites and the mechanisms of protection involved.
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Affiliation(s)
- Yun Shan Goh
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore
| | - Daniel McGuire
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Laurent Rénia
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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10
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Stanisic DI, Fink J, Mayer J, Coghill S, Gore L, Liu XQ, El-Deeb I, Rodriguez IB, Powell J, Willemsen NM, De SL, Ho MF, Hoffman SL, Gerrard J, Good MF. Vaccination with chemically attenuated Plasmodium falciparum asexual blood-stage parasites induces parasite-specific cellular immune responses in malaria-naïve volunteers: a pilot study. BMC Med 2018; 16:184. [PMID: 30293531 PMCID: PMC6174572 DOI: 10.1186/s12916-018-1173-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 09/11/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The continuing morbidity and mortality associated with infection with malaria parasites highlights the urgent need for a vaccine. The efficacy of sub-unit vaccines tested in clinical trials in malaria-endemic areas has thus far been disappointing, sparking renewed interest in the whole parasite vaccine approach. We previously showed that a chemically attenuated whole parasite asexual blood-stage vaccine induced CD4+ T cell-dependent protection against challenge with homologous and heterologous parasites in rodent models of malaria. METHODS In this current study, we evaluated the immunogenicity and safety of chemically attenuated asexual blood-stage Plasmodium falciparum (Pf) parasites in eight malaria-naïve human volunteers. Study participants received a single dose of 3 × 107 Pf pRBC that had been treated in vitro with the cyclopropylpyrolloindole analogue, tafuramycin-A. RESULTS We demonstrate that Pf asexual blood-stage parasites that are completely attenuated are immunogenic, safe and well tolerated in malaria-naïve volunteers. Following vaccination with a single dose, species and strain transcending Plasmodium-specific T cell responses were induced in recipients. This included induction of Plasmodium-specific lymphoproliferative responses, T cells secreting the parasiticidal cytokines, IFN-γ and TNF, and CD3+CD45RO+ memory T cells. Pf-specific IgG was not detected. CONCLUSIONS This is the first clinical study evaluating a whole parasite blood-stage malaria vaccine. Following administration of a single dose of completely attenuated Pf asexual blood-stage parasites, Plasmodium-specific T cell responses were induced while Pf-specific antibodies were not detected. These results support further evaluation of this chemically attenuated vaccine in humans. TRIAL REGISTRATION Trial registration: ACTRN12614000228684 . Registered 4 March 2014.
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Affiliation(s)
- Danielle I Stanisic
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia.
| | - James Fink
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Johanna Mayer
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Sarah Coghill
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Letitia Gore
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Xue Q Liu
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Ibrahim El-Deeb
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Ingrid B Rodriguez
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Jessica Powell
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Nicole M Willemsen
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Sai Lata De
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Mei-Fong Ho
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | | | - John Gerrard
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Michael F Good
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia.
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11
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Olsen TM, Stone BC, Chuenchob V, Murphy SC. Prime-and-Trap Malaria Vaccination To Generate Protective CD8 + Liver-Resident Memory T Cells. THE JOURNAL OF IMMUNOLOGY 2018; 201:1984-1993. [PMID: 30127085 DOI: 10.4049/jimmunol.1800740] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/02/2018] [Indexed: 11/19/2022]
Abstract
Tissue-resident memory CD8+ T (Trm) cells in the liver are critical for long-term protection against pre-erythrocytic Plasmodium infection. Such protection can usually be induced with three to five doses of i.v. administered radiation-attenuated sporozoites (RAS). To simplify and accelerate vaccination, we tested a DNA vaccine designed to induce potent T cell responses against the SYVPSAEQI epitope of Plasmodium yoelii circumsporozoite protein. In a heterologous "prime-and-trap" regimen, priming using gene gun-administered DNA and boosting with one dose of RAS attracted expanding Ag-specific CD8+ T cell populations to the liver, where they became Trm cells. Vaccinated in this manner, BALB/c mice were completely protected against challenge, an outcome not reliably achieved following one dose of RAS or following DNA-only vaccination. This study demonstrates that the combination of CD8+ T cell priming by DNA and boosting with liver-homing RAS enhances formation of a completely protective liver Trm cell response and suggests novel approaches for enhancing T cell-based pre-erythrocytic malaria vaccines.
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Affiliation(s)
- Tayla M Olsen
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98109.,Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, WA 98109
| | - Brad C Stone
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98109.,Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, WA 98109
| | - Vorada Chuenchob
- Center for Infectious Disease Research, University of Washington, Seattle, WA 98109; and
| | - Sean C Murphy
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98109; .,Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, WA 98109.,Department of Microbiology, University of Washington, Seattle, WA 98195
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12
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Kiakos K, Englinger B, Yanow SK, Wernitznig D, Jakupec MA, Berger W, Keppler BK, Hartley JA, Lee M, Patil PC. Design, synthesis, nuclear localization, and biological activity of a fluorescent duocarmycin analog, HxTfA. Bioorg Med Chem Lett 2018; 28:1342-1347. [PMID: 29548574 DOI: 10.1016/j.bmcl.2018.03.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/23/2018] [Accepted: 03/05/2018] [Indexed: 01/20/2023]
Abstract
HxTfA 4 is a fluorescent analog of a potent cytotoxic and antimalarial agent, TfA 3, which is currently being investigated for the development of an antimalarial vaccine, PlasProtect®. HxTfA contains a p-anisylbenzimidazole or Hx moiety, which is endowed with a blue emission upon excitation at 318 nm; thus enabling it to be used as a surrogate for probing the cellular fate of TfA using confocal microscopy, and addressing the question of nuclear localization. HxTfA exhibits similar selectivity to TfA for A-tract sequences of DNA, alkylating adenine-N3, albeit at 10-fold higher concentrations. It also possesses in vitro cytotoxicity against A549 human lung carcinoma cells and Plasmodium falciparum. Confocal microscopy studies showed for the first time that HxTfA, and by inference TfA, entered A549 cells and localized in the nucleus to exert its biological activity. At biologically relevant concentrations, HxTfA elicits DNA damage response as evidenced by a marked increase in the levels of γH2AX observed by confocal microscopy and immunoblotting studies, and ultimately induces apoptosis.
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Affiliation(s)
- Konstantinos Kiakos
- Cancer Research UK Drug-DNA Interactions Research Group, UCL Cancer Institute, London WC1E 6BT, United Kingdom; Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria; Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria.
| | - Bernhard Englinger
- Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | | | - Debora Wernitznig
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria; Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria
| | - Michael A Jakupec
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria; Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria
| | - Walter Berger
- Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria; Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Bernhard K Keppler
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria; Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Vienna, Austria
| | - John A Hartley
- Cancer Research UK Drug-DNA Interactions Research Group, UCL Cancer Institute, London WC1E 6BT, United Kingdom
| | - Moses Lee
- Department of Chemistry, Hope College, Holland, MI 49423, United States
| | - Pravin C Patil
- Department of Chemistry, Hope College, Holland, MI 49423, United States
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Ssemaganda A, Low LM, Verhoeft KR, Wambuzi M, Kawoozo B, Nabasumba SB, Mpendo J, Bagaya BS, Kiwanuka N, Stanisic DI, Berners-Price SJ, Good MF. Gold(i) phosphine compounds as parasite attenuating agents for malaria vaccine and drug development. Metallomics 2018; 10:444-454. [DOI: 10.1039/c7mt00311k] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The asexual blood-stagePlasmodiumparasite attenuating properties of gold(i) phosphine compounds are exploited in a novel strategy for malaria vaccine development.
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Affiliation(s)
| | | | | | - Mathias Wambuzi
- UVRI-IAVI HIV Vaccine Program
- Uganda Virus Research Institute
- Entebbe
- Uganda
| | - Barbarah Kawoozo
- UVRI-IAVI HIV Vaccine Program
- Uganda Virus Research Institute
- Entebbe
- Uganda
| | | | - Juliet Mpendo
- UVRI-IAVI HIV Vaccine Program
- Uganda Virus Research Institute
- Entebbe
- Uganda
| | - Bernard S. Bagaya
- UVRI-IAVI HIV Vaccine Program
- Uganda Virus Research Institute
- Entebbe
- Uganda
- Department of Immunology and Molecular Biology
| | - Noah Kiwanuka
- UVRI-IAVI HIV Vaccine Program
- Uganda Virus Research Institute
- Entebbe
- Uganda
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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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Iyori M, Blagborough AM, Sala KA, Nishiura H, Takagi K, Yoshida S. Protective efficacy of an IL-12-expressing baculoviral malaria vaccine. Parasite Immunol 2017; 39. [DOI: 10.1111/pim.12498] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/19/2017] [Indexed: 12/13/2022]
Affiliation(s)
- M. Iyori
- Laboratory of Vaccinology and Applied Immunology; Kanazawa University School of Pharmacy; Kanazawa Japan
| | | | - K. A. Sala
- Department of Life Sciences; Imperial College London; London UK
| | - H. Nishiura
- Laboratory of Vaccinology and Applied Immunology; Kanazawa University School of Pharmacy; Kanazawa Japan
| | - K. Takagi
- Laboratory of Vaccinology and Applied Immunology; Kanazawa University School of Pharmacy; Kanazawa Japan
| | - S. Yoshida
- Laboratory of Vaccinology and Applied Immunology; Kanazawa University School of Pharmacy; Kanazawa Japan
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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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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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18
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Giddam AK, Reiman JM, Zaman M, Skwarczynski M, Toth I, Good MF. A semi-synthetic whole parasite vaccine designed to protect against blood stage malaria. Acta Biomater 2016; 44:295-303. [PMID: 27544810 DOI: 10.1016/j.actbio.2016.08.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 08/12/2016] [Accepted: 08/16/2016] [Indexed: 12/14/2022]
Abstract
UNLABELLED Although attenuated malaria parasitized red blood cells (pRBCs) are promising vaccine candidates, their application in humans may be restricted for ethical and regulatory reasons. Therefore, we developed an organic microparticle-based delivery platform as a whole parasite malaria-antigen carrier to mimic pRBCs. Killed blood stage parasites were encapsulated within liposomes that are targeted to antigen presenting cells (APCs). Mannosylated lipid core peptides (MLCPs) were used as targeting ligands for the liposome-encapsulated parasite antigens. MLCP-liposomes, but not unmannosylated liposomes, were taken-up efficiently by APCs which then significantly upregulated expression of MHC-ll and costimulatory molecules, CD80 and CD86. Two such vaccines using rodent model systems were constructed - one with Plasmodium chabaudi and the other with P. yoelii. MLCP-liposome vaccines were able to control the parasite burden and extended the survival of mice. Thus, we have demonstrated an alternative delivery system to attenuated pRBCs with similar vaccine efficacy and added clinical advantages. Such liposomes are promising candidates for a human malaria vaccine. STATEMENT OF SIGNIFICANCE Attenuated whole parasite-based vaccines, by incorporating all parasite antigens, are very promising candidates, but issues relating to production, storage and safety concerns are significantly slowing their development. We therefore developed a semi-synthetic whole parasite malaria vaccine that is easily manufactured and stored. Two such prototype vaccines (a P. chabaudi and a P. yoelii vaccine) have been constructed. They are non-infectious, highly immunogenic and give good protection profiles. This semi-synthetic delivery platform is an exciting strategy to accelerate the development of a licensed malaria vaccine. Moreover, this strategy can be potentially applied to a wide range of pathogens.
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19
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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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20
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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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21
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Frevert U, Krzych U. Plasmodium cellular effector mechanisms and the hepatic microenvironment. Front Microbiol 2015; 6:482. [PMID: 26074888 PMCID: PMC4445044 DOI: 10.3389/fmicb.2015.00482] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/01/2015] [Indexed: 12/23/2022] Open
Abstract
Plasmodium falciparum malaria remains one of the most serious health problems globally. Immunization with attenuated parasites elicits multiple cellular effector mechanisms capable of eliminating Plasmodium liver stages. However, malaria liver stage (LS) immunity is complex and the mechanisms effector T cells use to locate the few infected hepatocytes in the large liver in order to kill the intracellular LS parasites remain a mystery to date. Here, we review our current knowledge on the behavior of CD8 effector T cells in the hepatic microvasculature, in malaria and other hepatic infections. Taking into account the unique immunological and lymphogenic properties of the liver, we discuss whether classical granule-mediated cytotoxicity might eliminate infected hepatocytes via direct cell contact or whether cytokines might operate without cell–cell contact and kill Plasmodium LSs at a distance. A thorough understanding of the cellular effector mechanisms that lead to parasite death hence sterile protection is a prerequisite for the development of a successful malaria vaccine to protect the 40% of the world’s population currently at risk of Plasmodium infection.
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Affiliation(s)
- Ute Frevert
- Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine , New York, NY, USA
| | - Urszula Krzych
- Division of Malaria Vaccine Development, Department of Cellular Immunology, Walter Reed Army Institute of Research , Silver Spring, MD, USA
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22
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Nahrendorf W, Spence PJ, Tumwine I, Lévy P, Jarra W, Sauerwein RW, Langhorne J. Blood-stage immunity to Plasmodium chabaudi malaria following chemoprophylaxis and sporozoite immunization. eLife 2015; 4. [PMID: 25714922 PMCID: PMC4371380 DOI: 10.7554/elife.05165] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/23/2015] [Indexed: 12/22/2022] Open
Abstract
Protection against malaria in humans can be achieved by repeated exposure to infected mosquito bites during prophylactic chloroquine treatment (chemoprophylaxis and sporozoites (CPS)). We established a new mouse model of CPS immunization to investigate the stage and strain-specificity of malaria immunity. Immunization with Plasmodium chabaudi by mosquito bite under chloroquine cover does not generate pre-erythrocytic immunity, which is acquired only after immunization with high sporozoite doses. Instead, CPS immunization by bite elicits long-lived protection against blood-stage parasites. Blood-stage immunity is effective against a virulent, genetically distinct strain of P. chabaudi. Importantly, if exposure to blood-stage parasitemia is extended, blood-stage parasites induce cross-stage immunity targeting pre-erythrocytic stages. We therefore show that CPS immunization can induce robust, long-lived heterologous blood-stage immunity, in addition to protection against pre-erythrocytic parasites following high dose sporozoite immunization. Cross-stage immunity elicited by blood-stage parasites may further enhance efficacy of this immunization regimen. DOI:http://dx.doi.org/10.7554/eLife.05165.001 Malaria is a life-threatening infectious disease in humans that is caused by a single-celled parasite called Plasmodium. The parasite is carried between people by mosquitos; when an infected mosquito bites a human, the parasite is injected into the bloodstream with the mosquito's saliva. Plasmodium first infects liver cells but then re-enters the bloodstream, where it infects red blood cells leading to symptoms of disease. If another mosquito bites the infected individual at this so-called ‘blood-stage’, the parasite can be passed to this mosquito and the cycle of transmission continues. Currently there are no vaccines available that can effectively protect against malaria. Although an experimental vaccine containing a weakened form of the parasite can protect against the liver-stage parasites, it fails to prevent the parasite from multiplying in the red blood cells. Therefore, the individuals remain susceptible to severe malaria. Recently, researchers have developed a new strategy for immunization that provides exposure to both liver-stage and blood-stage parasites. Human volunteers taking an anti-malarial drug were deliberately exposed to mosquitos carrying the parasite on three separate occasions. Although the volunteers were infected with the parasite, the anti-malarial drug killed the parasites inside the red blood cells. After the end of the drug treatment, the volunteers were exposed to mosquitos carrying the parasite and they were still protected from infection. These results are promising, but it is not clear if the volunteers have acquired immunity to liver-stage or blood-stage parasites, or even both. To answer this important question, Nahrendorf et al. developed a similar immunization strategy in mice. Just like the human volunteers, the mice were treated with an anti-malarial drug and exposed to mosquitos carrying Plasmodium on three separate occasions. Although the immunizations did not protect the mice against early infection in the liver, they did provide long-term protection against parasites multiplying in the red-blood cells. The immunity generated by this immunization strategy also protected the mice against another strain of Plasmodium, different to the one used in the immunizations. The experiments also show that prolonged exposure to the blood-stage parasites can even lead to immunity against the liver-stage parasites. Nahrendorf et al.'s findings show that this immunization strategy can protect individuals against both the liver-stage and blood-stage parasites. The next challenges are to find out how the immunity generated by one stage of infection can protect against the other stages, and to discover which molecules on the parasite the immune system targets. DOI:http://dx.doi.org/10.7554/eLife.05165.002
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Affiliation(s)
- Wiebke Nahrendorf
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Philip J Spence
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Irene Tumwine
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Prisca Lévy
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - William Jarra
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Jean Langhorne
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
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Proietti C, Doolan DL. The case for a rational genome-based vaccine against malaria. Front Microbiol 2015; 5:741. [PMID: 25657640 PMCID: PMC4302942 DOI: 10.3389/fmicb.2014.00741] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/06/2014] [Indexed: 12/22/2022] Open
Abstract
Historically, vaccines have been designed to mimic the immunity induced by natural exposure to the target pathogen, but this approach has not been effective for any parasitic pathogen of humans or complex pathogens that cause chronic disease in humans, such as Plasmodium. Despite intense efforts by many laboratories around the world on different aspects of Plasmodium spp. molecular and cell biology, epidemiology and immunology, progress towards the goal of an effective malaria vaccine has been disappointing. The premise of rational vaccine design is to induce the desired immune response against the key pathogen antigens or epitopes targeted by protective immune responses. We advocate that development of an optimally efficacious malaria vaccine will need to improve on nature, and that this can be accomplished by rational vaccine design facilitated by mining genomic, proteomic and transcriptomic datasets in the context of relevant biological function. In our opinion, modern genome-based rational vaccine design offers enormous potential above and beyond that of whole-organism vaccines approaches established over 200 years ago where immunity is likely suboptimal due to the many genetic and immunological host-parasite adaptations evolved to allow the Plasmodium parasite to coexist in the human host, and which are associated with logistic and regulatory hurdles for production and delivery.
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Affiliation(s)
- Carla Proietti
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute Brisbane, QLD, Australia
| | - Denise L Doolan
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute Brisbane, QLD, Australia
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Patil PC, Lee M. An efficient synthesis of furano analogs of duocarmycin C1 and C2: seco-iso-cyclopropylfurano[e]indoline-trimethoxyindole and seco-cyclopropylfurano[f]quinoline-trimethoxyindole. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.04.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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The whole parasite, pre-erythrocytic stage approach to malaria vaccine development: a review. Curr Opin Infect Dis 2014; 26:420-8. [PMID: 23982233 DOI: 10.1097/qco.0000000000000002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The whole sporozoite (SPZ) vaccine platform provides the only established approach for inducing high-level sustained protective immunity in humans against malaria. We introduce this platform, highlight literature published since 2011, and discuss the challenges of further development. RECENT FINDINGS There are three major approaches to development of a whole parasite vaccine to prevent malaria infection using the SPZ platform: radiation-attenuated sporozoites (irrSPZ), chemoprophylaxis with infectious sporozoites (CPS), and genetically attenuated parasites (GAPs). In all three, SPZ are administered to the vaccinee. All three protect animals against infection when administered by injection with a needle and syringe, and irrSPZ and CPS protect against Plasmodium falciparum malaria in humans when P. falciparum SPZ (PfSPZ) are administered by mosquito bite. Metabolically active, nonreplicating (radiation attenuated) aseptic, purified, cryopreserved PfSPZ (PfSPZ Vaccine), and infectious, aseptic, purified, cryopreserved PfSPZ administered with chemoprophylaxis (PfSPZ-CVac approach) administered by needle and syringe have entered clinical trials. Preliminary data indicate that the PfSPZ Vaccine is safe, well tolerated and highly protective when administered intravenously. SUMMARY With proof-of-concept now established for high-grade protection induced by parenteral administration of a whole sporozoite vaccine, pathways for further development are currently being defined. Demonstration of high-level, durable, cross-strain P. falciparum protection would set the stage for licensure of a vaccine that could lead to dramatic reductions in malaria morbidity and mortality, and eventually elimination of this ancient scourge.
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Stanisic DI, Barry AE, Good MF. Escaping the immune system: How the malaria parasite makes vaccine development a challenge. Trends Parasitol 2013; 29:612-22. [DOI: 10.1016/j.pt.2013.10.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 10/01/2013] [Accepted: 10/01/2013] [Indexed: 10/26/2022]
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Abstract
Malaria, which is caused by Plasmodium spp., starts with an asymptomatic phase, during which sporozoites, the parasite form that is injected into the skin by a mosquito, develop into merozoites, the form that infects erythrocytes. This pre-erythrocytic phase is still the most enigmatic in the parasite life cycle, but has long been recognized as an attractive vaccination target. In this Review, we present what has been learned in recent years about the natural history of the pre-erythrocytic stages, mainly using intravital imaging in rodents. We also consider how this new knowledge is in turn changing our understanding of the immune response mounted by the host against the pre-erythrocytic forms.
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28
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Frevert U, Nacer A, Cabrera M, Movila A, Leberl M. Imaging Plasmodium immunobiology in the liver, brain, and lung. Parasitol Int 2013; 63:171-86. [PMID: 24076429 DOI: 10.1016/j.parint.2013.09.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 08/28/2013] [Accepted: 09/18/2013] [Indexed: 01/10/2023]
Abstract
Plasmodium falciparum malaria is responsible for the deaths of over half a million African children annually. Until a decade ago, dynamic analysis of the malaria parasite was limited to in vitro systems with the typical limitations associated with 2D monocultures or entirely artificial surfaces. Due to extremely low parasite densities, the liver was considered a black box in terms of Plasmodium sporozoite invasion, liver stage development, and merozoite release into the blood. Further, nothing was known about the behavior of blood stage parasites in organs such as the brain where clinical signs manifest and the ensuing immune response of the host that may ultimately result in a fatal outcome. The advent of fluorescent parasites, advances in imaging technology, and availability of an ever-increasing number of cellular and molecular probes have helped illuminate many steps along the pathogenetic cascade of this deadly tropical parasite.
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Affiliation(s)
- Ute Frevert
- Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine, 341 E 25 Street, New York, NY 10010, USA.
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In vivo CD8+ T cell dynamics in the liver of Plasmodium yoelii immunized and infected mice. PLoS One 2013; 8:e70842. [PMID: 23967119 PMCID: PMC3743839 DOI: 10.1371/journal.pone.0070842] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/21/2013] [Indexed: 12/28/2022] Open
Abstract
Plasmodium falciparum malaria remains one of the most serious health problems globally and a protective malaria vaccine is desperately needed. Vaccination with attenuated parasites elicits multiple cellular effector mechanisms that lead to Plasmodium liver stage elimination. While granule-mediated cytotoxicity requires contact between CD8+ effector T cells and infected hepatocytes, cytokine secretion should allow parasite killing over longer distances. To better understand the mechanism of parasite elimination in vivo, we monitored the dynamics of CD8+ T cells in the livers of naïve, immunized and sporozoite-infected mice by intravital microscopy. We found that immunization of BALB/c mice with attenuated P. yoelii 17XNL sporozoites significantly increases the velocity of CD8+ T cells patrolling the hepatic microvasculature from 2.69±0.34 μm/min in naïve mice to 5.74±0.66 μm/min, 9.26±0.92 μm/min, and 7.11±0.73 μm/min in mice immunized with irradiated, early genetically attenuated (Pyuis4-deficient), and late genetically attenuated (Pyfabb/f-deficient) parasites, respectively. Sporozoite infection of immunized mice revealed a 97% and 63% reduction in liver stage density and volume, respectively, compared to naïve controls. To examine cellular mechanisms of immunity in situ, naïve mice were passively immunized with hepatic or splenic CD8+ T cells. Unexpectedly, adoptive transfer rendered the motile CD8+ T cells from immunized mice immotile in the liver of P. yoelii infected mice. Similarly, when mice were simultaneously inoculated with viable sporozoites and CD8+ T cells, velocities 18 h later were also significantly reduced to 0.68±0.10 μm/min, 1.53±0.22 μm/min, and 1.06±0.26 μm/min for CD8+ T cells from mice immunized with irradiated wild type sporozoites, Pyfabb/f-deficient parasites, and P. yoelii CS280–288 peptide, respectively. Because immobilized CD8+ T cells are unable to make contact with infected hepatocytes, soluble mediators could potentially play a key role in parasite elimination under these experimental conditions.
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Controlling the radical 5-exo-trig cyclization, and selective synthesis of seco-iso-cyclopropylfurano[e]indoline (seco-iso-CFI) and seco-cyclopropylthiophene[e]indoline (seco-CTI) DNA alkylating subunit of the duocarmycins. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.06.116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Good MF, Reiman JM, Rodriguez IB, Ito K, Yanow SK, El-Deeb IM, Batzloff MR, Stanisic DI, Engwerda C, Spithill T, Hoffman SL, Lee M, McPhun V. Cross-species malaria immunity induced by chemically attenuated parasites. J Clin Invest 2013; 123:66634. [PMID: 23863622 PMCID: PMC4011145 DOI: 10.1172/jci66634] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 04/26/2013] [Indexed: 01/29/2023] Open
Abstract
Vaccine development for the blood stages of malaria has focused on the induction of antibodies to parasite surface antigens, most of which are highly polymorphic. An alternate strategy has evolved from observations that low-density infections can induce antibody-independent immunity to different strains. To test this strategy, we treated parasitized red blood cells from the rodent parasite Plasmodium chabaudi with seco-cyclopropyl pyrrolo indole analogs. These drugs irreversibly alkylate parasite DNA, blocking their ability to replicate. After administration in mice, DNA from the vaccine could be detected in the blood for over 110 days and a single vaccination induced profound immunity to different malaria parasite species. Immunity was mediated by CD4+ T cells and was dependent on the red blood cell membrane remaining intact. The human parasite, Plasmodium falciparum, could also be attenuated by treatment with seco-cyclopropyl pyrrolo indole analogs. These data demonstrate that vaccination with chemically attenuated parasites induces protective immunity and provide a compelling rationale for testing a blood-stage parasite-based vaccine targeting human Plasmodium species.
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Nganou-Makamdop K, Sauerwein RW. Liver or blood-stage arrest during malaria sporozoite immunization: the later the better? Trends Parasitol 2013; 29:304-10. [PMID: 23608185 DOI: 10.1016/j.pt.2013.03.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 03/01/2013] [Accepted: 03/18/2013] [Indexed: 10/26/2022]
Abstract
So far, the best immunization strategies to achieve high levels of protection against malaria are based on whole parasites. Complete sterile protection can be obtained in rodent models after immunization with sporozoites and chemoprophylaxis, or with sporozoites attenuated either genetically or by radiation. These approaches target specific stages, with arrests occurring at different time-points of the parasite life cycle. Here, we review these different approaches in relation to their capacity to induce protection in both Plasmodium berghei and Plasmodium yoelii models. The combined data suggest that maximal liver-stage exposure without further development into blood stages may induce the most efficient protection in mice.
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Affiliation(s)
- Krystelle Nganou-Makamdop
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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Obeid M, Franetich JF, Lorthiois A, Gego A, Grüner AC, Tefit M, Boucheix C, Snounou G, Mazier D. Skin-draining lymph node priming is sufficient to induce sterile immunity against pre-erythrocytic malaria. EMBO Mol Med 2012; 5:250-63. [PMID: 23255300 PMCID: PMC3569641 DOI: 10.1002/emmm.201201677] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 10/26/2012] [Accepted: 11/09/2012] [Indexed: 12/23/2022] Open
Abstract
The Plasmodium-infected hepatocyte has been considered necessary to prime the immune responses leading to sterile protection after vaccination with attenuated sporozoites. However, it has recently been demonstrated that priming also occurs in the skin. We wished to establish if sterile protection could be obtained in the absence of priming by infected hepatocytes. To this end, we developed a subcutaneous (s.c.) immunization protocol where few, possibly none, of the immunizing irradiated Plasmodium yoelii sporozoites infect hepatocytes, and also used CD81-deficient mice non-permissive to productive hepatocyte infections. We then compared and contrasted the patterns of priming with those obtained by intradermal immunization, where priming occurs in the liver. Using sterile immunity as a primary read-out, we exploited an inhibitor of T-cell migration, transgenic mice with conditional depletion of dendritic cells and adoptive transfers of draining lymph node-derived T cells, to provide evidence that responses leading to sterile immunity can be primed in the skin-draining lymph nodes with little, if any, contribution from the infected hepatocyte.
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The species specificity of immunity generated by live whole organism immunisation with erythrocytic and pre-erythrocytic stages of rodent malaria parasites and implications for vaccine development. Int J Parasitol 2012; 42:859-70. [DOI: 10.1016/j.ijpara.2012.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/29/2012] [Accepted: 07/03/2012] [Indexed: 11/20/2022]
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Butler NS, Vaughan AM, Harty JT, Kappe SH. Whole parasite vaccination approaches for prevention of malaria infection. Trends Immunol 2012; 33:247-54. [DOI: 10.1016/j.it.2012.02.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 12/27/2011] [Accepted: 02/02/2012] [Indexed: 12/14/2022]
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Annoura T, Ploemen IHJ, van Schaijk BCL, Sajid M, Vos MW, van Gemert GJ, Chevalley-Maurel S, Franke-Fayard BMD, Hermsen CC, Gego A, Franetich JF, Mazier D, Hoffman SL, Janse CJ, Sauerwein RW, Khan SM. Assessing the adequacy of attenuation of genetically modified malaria parasite vaccine candidates. Vaccine 2012; 30:2662-70. [PMID: 22342550 DOI: 10.1016/j.vaccine.2012.02.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 02/02/2012] [Accepted: 02/03/2012] [Indexed: 11/30/2022]
Abstract
The critical first step in the clinical development of a malaria vaccine, based on live-attenuated Plasmodium falciparum sporozoites, is the guarantee of complete arrest in the liver. We report on an approach for assessing adequacy of attenuation of genetically attenuated sporozoites in vivo using the Plasmodium berghei model of malaria and P. falciparum sporozoites cultured in primary human hepatocytes. We show that two genetically attenuated sporozoite vaccine candidates, Δp52+p36 and Δfabb/f, are not adequately attenuated. Sporozoites infection of mice with both P. berghei candidates can result in blood infections. We also provide evidence that P. falciparum sporozoites of the leading vaccine candidate that is similarly attenuated through the deletion of the genes encoding the proteins P52 and P36, can develop into replicating liver stages. Therefore, we propose a minimal set of screening criteria to assess adequacy of sporozoite attenuation necessary before advancing into further clinical development and studies in humans.
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Affiliation(s)
- Takeshi Annoura
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
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Butler NS, Schmidt NW, Vaughan AM, Aly AS, Kappe SHI, Harty JT. Superior antimalarial immunity after vaccination with late liver stage-arresting genetically attenuated parasites. Cell Host Microbe 2011; 9:451-62. [PMID: 21669394 DOI: 10.1016/j.chom.2011.05.008] [Citation(s) in RCA: 182] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 04/20/2011] [Accepted: 05/31/2011] [Indexed: 10/18/2022]
Abstract
While subunit vaccines have shown partial efficacy in clinical trials, radiation-attenuated sporozoites (RAS) remain the "gold standard" for sterilizing protection against Plasmodium infection in human vaccinees. The variability in immunogenicity and replication introduced by the extensive, random DNA damage necessary to generate RAS could be overcome by genetically attenuated parasites (GAP) designed via gene deletion to arrest at defined points during liver-stage development. Here, we demonstrate the principle that late liver stage-arresting GAP induce larger and broader CD8 T cell responses that provide superior protection in inbred and outbred mice compared to RAS or early-arresting GAP immunizations. Late liver stage-arresting GAP also engender high levels of cross-stage and cross-species protection and complete protection when administered by translationally relevant intradermal or subcutaneous routes. Collectively, our results underscore the potential utility of late liver stage-arresting GAP as broadly protective next-generation live-attenuated malaria vaccines and support their potential as a powerful model for identifying antigens to generate cross-stage protection.
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Affiliation(s)
- Noah S Butler
- Department of Microbiology, University of Iowa, 3-512 Bowen Science Building, Iowa City, IA 52242, USA
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Gerald NJ, Majam V, Mahajan B, Kozakai Y, Kumar S. Protection from experimental cerebral malaria with a single dose of radiation-attenuated, blood-stage Plasmodium berghei parasites. PLoS One 2011; 6:e24398. [PMID: 21935405 PMCID: PMC3174172 DOI: 10.1371/journal.pone.0024398] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 08/08/2011] [Indexed: 12/31/2022] Open
Abstract
Background Whole malaria parasites are highly effective in inducing immunity against malaria. Due to the limited success of subunit based vaccines in clinical studies, there has been a renewed interest in whole parasite-based malaria vaccines. Apart from attenuated sporozoites, there have also been efforts to use live asexual stage parasites as vaccine immunogens. Methodology and Results We used radiation exposure to attenuate the highly virulent asexual blood stages of the murine malaria parasite P. berghei to a non-replicable, avirulent form. We tested the ability of the attenuated blood stage parasites to induce immunity to parasitemia and the symptoms of severe malaria disease. Depending on the mouse genetic background, a single high dose immunization without adjuvant protected mice from parasitemia and severe disease (CD1 mice) or from experimental cerebral malaria (ECM) (C57BL/6 mice). A low dose immunization did not protect against parasitemia or severe disease in either model after one or two immunizations. The protection from ECM was associated with a parasite specific antibody response and also with a lower level of splenic parasite-specific IFN-γ production, which is a mediator of ECM pathology in C57BL/6 mice. Surprisingly, there was no difference in the sequestration of CD8+ T cells and CD45+ CD11b+ macrophages in the brains of immunized, ECM-protected mice. Conclusions This report further demonstrates the effectiveness of a whole parasite blood-stage vaccine in inducing immunity to malaria and explicitly demonstrates its effectiveness against ECM, the most pathogenic consequence of malaria infection. This experimental model will be important to explore the formulation of whole parasite blood-stage vaccines against malaria and to investigate the immune mechanisms that mediate protection against parasitemia and cerebral malaria.
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Affiliation(s)
- Noel J. Gerald
- Division of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland, United States of America
| | - Victoria Majam
- Division of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland, United States of America
| | - Babita Mahajan
- Division of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland, United States of America
| | - Yukiko Kozakai
- Division of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland, United States of America
| | - Sanjai Kumar
- Division of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland, United States of America
- * E-mail:
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Borrmann S, Matuschewski K. Protective immunity against malaria by 'natural immunization': a question of dose, parasite diversity, or both? Curr Opin Immunol 2011; 23:500-8. [PMID: 21719266 DOI: 10.1016/j.coi.2011.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 05/29/2011] [Indexed: 10/18/2022]
Abstract
Plasmodium undergoes an obligate liver phase before the onset of malaria, which is caused exclusively by cyclic propagation of the parasite inside erythrocytes. The diagnostically inaccessible and clinically silent pre-erythrocytic expansion phase is a promising target for inducing sterilizing immunity against reinfections. Recent studies in rodent and human malaria models called attention to the induction of potent protective immunity by administration of anti-malarial drugs during sporozoite exposure. Here, we review the concept of drug-mediated pathogen arrest as a natural immunization strategy. This previously unrecognized immunological benefit might also open new opportunities for population-wide presumptive drug administration as an adjunct malaria control tool.
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Affiliation(s)
- Steffen Borrmann
- Clinical Parasitology Unit, Heidelberg University School of Medicine, 69120 Heidelberg, Germany.
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Harnessing immune responses against Plasmodium for rational vaccine design. Trends Parasitol 2011; 27:274-83. [PMID: 21531627 DOI: 10.1016/j.pt.2011.01.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 01/11/2011] [Accepted: 01/12/2011] [Indexed: 01/06/2023]
Abstract
In recent years, groundbreaking advances have been made in understanding the biology of and immune mechanisms against the Plasmodium spp. parasite, the causative agent of malaria. Novel features of the Plasmodium life cycle have been unravelled and immune mechanisms, which take place during both infection and immunization, have been dissected. We have undoubtedly enhanced our knowledge, but the question now is how to use this information to manipulate immune responses against Plasmodium and to develop an efficacious malaria vaccine. In this review, we discuss the latest developments in the field and speculate on how immune responses against Plasmodium could be harnessed for rational vaccine design and application.
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Good MF. Our impasse in developing a malaria vaccine. Cell Mol Life Sci 2011; 68:1105-13. [PMID: 21327616 PMCID: PMC11115129 DOI: 10.1007/s00018-011-0634-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/28/2010] [Accepted: 01/27/2011] [Indexed: 10/18/2022]
Abstract
Malaria presents a challenge to world health that to date has been beyond the abilities of researchers to conquer. This critique presents some of the strategies employed by the parasite to overcome immunity and the immunological challenges that we face to develop vaccines. A conclusion is that a vaccine must identify novel antigens or epitopes that are not normally immunogenic and which are therefore not under immune pressure and most likely to be conserved between different strains. Such antigens are most likely to be targets of cellular immunity. The case for a whole parasite blood stage vaccine is presented based on these premises.
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Affiliation(s)
- Michael F Good
- Institute for Glycomics, Gold Coast Campus, Griffith University, Gold Coast, QLD, 4222, Australia.
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CULLETON RL, INOUE M, REECE SE, CHEESMAN S, CARTER R. Strain-specific immunity induced by immunization with pre-erythrocytic stages of Plasmodium chabaudi. Parasite Immunol 2010; 33:73-8. [DOI: 10.1111/j.1365-3024.2010.01251.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Coban C, Horii T, Akira S, Ishii KJ. TLR9 and endogenous adjuvants of the whole blood-stage malaria vaccine. Expert Rev Vaccines 2010; 9:775-84. [PMID: 20624050 DOI: 10.1586/erv.10.60] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Vaccination has been a successful tool in the protection against many infectious diseases, and recent advances in biotechnology have created new techniques and strategies to produce safe and efficacious vaccines for human use. However, developing a protective vaccine against malaria has been a challenge. In this article, we focus on an old approach with some new modifications, the so-called whole-parasite vaccination strategy against blood-stage Plasmodium falciparum, the deadliest human malarial agent. In addition, we discuss recent developments in our understanding of how the endogenous adjuvant activity in the parasites, which functions via Toll-like receptor 9, acts as a double-edged sword between protective vaccination and pathological responses against malaria infection.
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Affiliation(s)
- Cevayir Coban
- Immunology Frontier Research Center, World Premier Institute for Immunology, Osaka University, Suita, Osaka 565-0871, Japan.
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Guilbride DL, Gawlinski P, Guilbride PDL. Why functional pre-erythrocytic and bloodstage malaria vaccines fail: a meta-analysis of fully protective immunizations and novel immunological model. PLoS One 2010; 5:e10685. [PMID: 20502667 PMCID: PMC2873430 DOI: 10.1371/journal.pone.0010685] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 04/16/2010] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Clinically protective malaria vaccines consistently fail to protect adults and children in endemic settings, and at best only partially protect infants. METHODOLOGY/PRINCIPAL FINDINGS We identify and evaluate 1916 immunization studies between 1965-February 2010, and exclude partially or nonprotective results to find 177 completely protective immunization experiments. Detailed reexamination reveals an unexpectedly mundane basis for selective vaccine failure: live malaria parasites in the skin inhibit vaccine function. We next show published molecular and cellular data support a testable, novel model where parasite-host interactions in the skin induce malaria-specific regulatory T cells, and subvert early antigen-specific immunity to parasite-specific immunotolerance. This ensures infection and tolerance to reinfection. Exposure to Plasmodium-infected mosquito bites therefore systematically triggers immunosuppression of endemic vaccine-elicited responses. The extensive vaccine trial data solidly substantiate this model experimentally. CONCLUSIONS/SIGNIFICANCE We conclude skinstage-initiated immunosuppression, unassociated with bloodstage parasites, systematically blocks vaccine function in the field. Our model exposes novel molecular and procedural strategies to significantly and quickly increase protective efficacy in both pipeline and currently ineffective malaria vaccines, and forces fundamental reassessment of central precepts determining vaccine development. This has major implications for accelerated local eliminations of malaria, and significantly increases potential for eradication.
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Kun JF, de Carvalho EG. Novel therapeutic targets in Plasmodium falciparum: aquaglyceroporins. Expert Opin Ther Targets 2009; 13:385-94. [PMID: 19335062 DOI: 10.1517/14728220902817839] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Malaria is caused by the intracellular parasite Plasmodium falciparum. The constant need for novel malaria therapies is due to the development of resistance against existing drugs. OBJECTIVE To summarise attempts to investigate parasitic aquaporins as drug targets in malaria. METHODS Starting with a summary of the history of malaria we present aquaporin structure and function relationships. Potential interactions of inhibitors with plasmodial AQP (PfAQP) are discussed. PfAQP blockage is examined in the light of recent work on knock-out parasites. Since PfAQP is able to transport other small solutes the parasites are sensitive to other compounds which are harmless to the human host. RESULTS/CONCLUSIONS Total blockage of PfAQP may not lead to the death of the parasite but application of PfAQP as a vehicle for toxic substances may be a further pathway for research.
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Affiliation(s)
- Jürgen F Kun
- Department of Parasitology, Institute for Tropical Medicine, Tübingen, Germany.
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