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Chatterjee D, Cockburn IA. The challenges of a circumsporozoite protein-based malaria vaccine. Expert Rev Vaccines 2021; 20:113-125. [PMID: 33554669 DOI: 10.1080/14760584.2021.1874924] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION A safe and effective vaccine will likely be necessary for the control or eradication of malaria which kills 400,000 annually. Our most advanced vaccine candidate to date is RTS,S which is based on the Plasmodium falciparum circumsporozoite protein (PfCSP) of the malaria parasite. However, protection by RTS,S is incomplete and short-lived. AREAS COVERED Here we summarize results from recent clinical trials of RTS,S and critically evaluate recent studies that aim to understand the correlates of protective immunity and why vaccine-induced protection is short-lived. In particular, recent systems serology studies have highlighted a key role for the necessity of inducing functional antibodies. In-depth analyses of immune responses to CSP in both mouse models and vaccinated humans have also highlighted difficulties in generating the maintaining high-quality antibody responses. Finally, in recent years biophysical and structural studies of antibody binding to PfCSP have led to a better understanding of how highly potent antibodies can block infection, which can inform vaccine design. EXPERT OPINION We highlight how both structure-guided vaccine design and a better understanding of the immune response to PfCSP can inform a second generation of PfCSP-based vaccines stimulating a broader range of protective targets within PfCSP.
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Affiliation(s)
- Deepyan Chatterjee
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, the Australian National University, Canberra, Australia
| | - Ian Andrew Cockburn
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, the Australian National University, Canberra, Australia
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2
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Smith EC, Limbach KJ, Rangel N, Oda K, Bolton JS, Du M, Gowda K, Wang J, Moch JK, Sonawane S, Velasco R, Belmonte A, Danner R, Lumsden JM, Patterson NB, Sedegah M, Hollingdale MR, Richie TL, Sacci JB, Villasante ED, Aguiar JC. Novel malaria antigen Plasmodium yoelii E140 induces antibody-mediated sterile protection in mice against malaria challenge. PLoS One 2020; 15:e0232234. [PMID: 32407410 PMCID: PMC7224506 DOI: 10.1371/journal.pone.0232234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/09/2020] [Indexed: 11/18/2022] Open
Abstract
Only a small fraction of the antigens expressed by malaria parasites have been evaluated as vaccine candidates. A successful malaria subunit vaccine will likely require multiple antigenic targets to achieve broad protection with high protective efficacy. Here we describe protective efficacy of a novel antigen, Plasmodium yoelii (Py) E140 (PyE140), evaluated against P. yoelii challenge of mice. Vaccines targeting PyE140 reproducibly induced up to 100% sterile protection in both inbred and outbred murine challenge models. Although PyE140 immunization induced high frequency and multifunctional CD8+ T cell responses, as well as CD4+ T cell responses, protection was mediated by PyE140 antibodies acting against blood stage parasites. Protection in mice was long-lasting with up to 100% sterile protection at twelve weeks post-immunization and durable high titer anti-PyE140 antibodies. The E140 antigen is expressed in all Plasmodium species, is highly conserved in both P. falciparum lab-adapted strains and endemic circulating parasites, and is thus a promising lead vaccine candidate for future evaluation against human malaria parasite species.
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Affiliation(s)
- Emily C. Smith
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Keith J. Limbach
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Nonenipha Rangel
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
| | - Kyosuke Oda
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
| | - Jessica S. Bolton
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Mengyan Du
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Kalpana Gowda
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Jianyang Wang
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
| | - J. Kathleen Moch
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Sharvari Sonawane
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Rachel Velasco
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Arnel Belmonte
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Rebecca Danner
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Joanne M. Lumsden
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Noelle B. Patterson
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Michael R. Hollingdale
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Thomas L. Richie
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - John B. Sacci
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Eileen D. Villasante
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Joao C. Aguiar
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
- * E-mail:
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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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4
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Bruder JT, Chen P, Ekberg G, Smith EC, Lazarski CA, Myers BA, Bolton J, Sedegah M, Villasante E, Richie TL, King CR, Aguiar JC, Doolan DL, Brough DE. Profiling the Targets of Protective CD8 + T Cell Responses to Infection. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2017; 7:20-31. [PMID: 28948187 PMCID: PMC5602877 DOI: 10.1016/j.omtm.2017.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 08/14/2017] [Indexed: 11/22/2022]
Abstract
T cells are critical effectors of host immunity that target intracellular pathogens, such as the causative agents of HIV, tuberculosis, and malaria. The development of vaccines that induce effective cell-mediated immunity against such pathogens has proved challenging; for tuberculosis and malaria, many of the antigens targeted by protective T cells are not known. Here, we report a novel approach for screening large numbers of antigens as potential targets of T cells. Malaria provides an excellent model to test this antigen discovery platform because T cells are critical mediators of protection following immunization with live sporozoite vaccines and the specific antigen targets are unknown. We generated an adenovirus array by cloning 312 highly expressed pre-erythrocytic Plasmodium yoelii antigens into adenovirus vectors using high-throughput methodologies. The array was screened to identify antigen-specific CD8+ T cells induced by a live sporozoite vaccine regimen known to provide high levels of sterile protection mediated by CD8+ T cells. We identified 69 antigens that were targeted by CD8+ T cells induced by this vaccine regimen. The antigen that recalled the highest frequency of CD8+ T cells, PY02605, induced protective responses in mice, demonstrating proof of principle for this approach in identifying antigens for vaccine development.
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Affiliation(s)
- Joseph T. Bruder
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
- Corresponding author: Joseph T. Bruder, Summit Consulting, 567 Chestertown Street, Gaithersburg, MD 20878, USA.
| | - Ping Chen
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Greg Ekberg
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Emily C. Smith
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Suite 100, Bethesda, MD 20817, USA
| | | | - Bennett A. Myers
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Jessica Bolton
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Suite 100, Bethesda, MD 20817, USA
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Eileen Villasante
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Thomas L. Richie
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - C. Richter King
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Joao C. Aguiar
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
- Camris International, 3 Bethesda Metro Center, 16th Floor, Bethesda, MD 20814, USA
| | - Denise L. Doolan
- Australian Institute of Tropical Health and Medicine, James Cook University, McGregor Road, Cairns, QLD 4870, Australia
| | - Douglas E. Brough
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
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Long-Term Immunity to Trypanosoma cruzi in the Absence of Immunodominant trans-Sialidase-Specific CD8+ T Cells. Infect Immun 2016; 84:2627-38. [PMID: 27354447 DOI: 10.1128/iai.00241-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/24/2016] [Indexed: 11/20/2022] Open
Abstract
Trypanosoma cruzi infection drives the expansion of remarkably focused CD8(+) T cell responses targeting epitopes encoded by variant trans-sialidase (TS) genes. Infection of C57BL/6 mice with T. cruzi results in up to 40% of all CD8(+) T cells committed to recognition of the dominant TSKB20 and subdominant TSKB18 TS epitopes. However, despite this enormous response, these mice fail to clear T. cruzi infection and subsequently develop chronic disease. One possible reason for the failure to cure T. cruzi infection is that immunodomination by these TS-specific T cells may interfere with alternative CD8(+) T cell responses more capable of complete parasite elimination. To address this possibility, we created transgenic mice that are centrally tolerant to these immunodominant epitopes. Mice expressing TSKB20, TSKB18, or both epitopes controlled T. cruzi infection and developed effector CD8(+) T cells that maintained an activated phenotype. Memory CD8(+) T cells from drug-cured TSKB-transgenic mice rapidly responded to secondary T. cruzi infection. In the absence of the response to TSKB20 and TSKB18, immunodominance did not shift to other known subdominant epitopes despite the capacity of these mice to expand epitope-specific T cells specific for the model antigen ovalbumin expressed by engineered parasites. Thus, CD8(+) T cell responses tightly and robustly focused on a few epitopes within variant TS antigens appear to neither contribute to, nor detract from, the ability to control T. cruzi infection. These data also indicate that the relative position of an epitope within a CD8(+) immunodominance hierarchy does not predict its importance in pathogen control.
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6
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Stone BC, Kas A, Billman ZP, Fuller DH, Fuller JT, Shendure J, Murphy SC. Complex Minigene Library Vaccination for Discovery of Pre-Erythrocytic Plasmodium T Cell Antigens. PLoS One 2016; 11:e0153449. [PMID: 27070430 PMCID: PMC4829254 DOI: 10.1371/journal.pone.0153449] [Citation(s) in RCA: 6] [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: 12/15/2015] [Accepted: 03/30/2016] [Indexed: 01/15/2023] Open
Abstract
Development of a subunit vaccine targeting liver-stage Plasmodium parasites requires the identification of antigens capable of inducing protective T cell responses. However, traditional methods of antigen identification are incapable of evaluating T cell responses against large numbers of proteins expressed by these parasites. This bottleneck has limited development of subunit vaccines against Plasmodium and other complex intracellular pathogens. To address this bottleneck, we are developing a synthetic minigene technology for multi-antigen DNA vaccines. In an initial test of this approach, pools of long (150 bp) antigen-encoding oligonucleotides were synthesized and recombined into vectors by ligation-independent cloning to produce two DNA minigene library vaccines. Each vaccine encoded peptides derived from 36 (vaccine 1) and 53 (vaccine 2) secreted or transmembrane pre-erythrocytic P. yoelii proteins. BALB/cj mice were vaccinated three times with a single vaccine by biolistic particle delivery (gene gun) and screened for interferon-γ-producing T cell responses by ELISPOT. Library vaccination induced responses against four novel antigens. Naïve mice exposed to radiation-attenuated sporozoites mounted a response against only one of the four novel targets (PyMDH, malate dehydrogenase). The response to PyMDH could not be recalled by additional homologous sporozoite immunizations but could be partially recalled by heterologous cross-species sporozoite exposure. Vaccination against the dominant PyMDH epitope by DNA priming and recombinant Listeria boosting did not protect against sporozoite challenge. Improvements in library design and delivery, combined with methods promoting an increase in screening sensitivity, may enable complex minigene screening to serve as a high-throughput system for discovery of novel T cell antigens.
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Affiliation(s)
- Brad C. Stone
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- * E-mail: (BCS); (SCM)
| | - Arnold Kas
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Zachary P. Billman
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Deborah H. Fuller
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - James T. Fuller
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Sean C. Murphy
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Human Challenge Center, Center for Infectious Disease Research, Seattle, Washington, United States of America
- * E-mail: (BCS); (SCM)
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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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Aguiar JC, Bolton J, Wanga J, Sacci JB, Iriko H, Mazeika JK, Han ET, Limbach K, Patterson NB, Sedegah M, Cruz AM, Tsuboi T, Hoffman SL, Carucci D, Hollingdale MR, Villasante ED, Richie TL. Discovery of Novel Plasmodium falciparum Pre-Erythrocytic Antigens for Vaccine Development. PLoS One 2015; 10:e0136109. [PMID: 26292257 PMCID: PMC4546230 DOI: 10.1371/journal.pone.0136109] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/29/2015] [Indexed: 02/07/2023] Open
Abstract
Background Nearly 100% protection against malaria infection can be achieved in humans by immunization with P. falciparum radiation-attenuated sporozoites (RAS). Although it is thought that protection is mediated by T cell and antibody responses, only a few of the many pre-erythrocytic (sporozoite and liver stage) antigens that are targeted by these responses have been identified. Methodology Twenty seven P. falciparum pre-erythrocytic antigens were selected using bioinformatics analysis and expression databases and were expressed in a wheat germ cell-free protein expression system. Recombinant proteins were recognized by plasma from RAS-immunized subjects, and 21 induced detectable antibody responses in mice and rabbit and sera from these immunized animals were used to characterize these antigens. All 21 proteins localized to the sporozoite: five localized to the surface, seven localized to the micronemes, cytoplasm, endoplasmic reticulum or nucleus, two localized to the surface and cytoplasm, and seven remain undetermined. PBMC from RAS-immunized volunteers elicited positive ex vivo or cultured ELISpot responses against peptides from 20 of the 21 antigens. Conclusions These T cell and antibody responses support our approach of using reagents from RAS-immunized subjects to screen potential vaccine antigens, and have led to the identification of a panel of novel P. falciparum antigens. These results provide evidence to further evaluate these antigens as vaccine candidates. Trial Registration ClinicalTrials.gov NCT00870987 ClinicalTrials.gov NCT00392015
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Affiliation(s)
- Joao C. Aguiar
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
- Camris International, Bethesda, MD 20814, United States of America
- * E-mail:
| | - Jessica Bolton
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, United States of America
| | - Joyce Wanga
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
- Technical Resources International, Inc., Bethesda, MD 20817, United States of America
| | - John B. Sacci
- Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Hideyuki Iriko
- Department of International Health, Kobe University Graduate School of Health Science, Kobe 654-0142, Japan
| | - Julie K. Mazeika
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
- EMD Millipore Corporation, North Andover, MA 01845, United States of America
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Republic of Korea
| | - Keith Limbach
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, United States of America
| | - Noelle B. Patterson
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, United States of America
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
| | - Ann-Marie Cruz
- PATH Malaria Vaccine Initiative, Washington, DC 20001, United States of America
| | - Takafumi Tsuboi
- Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Stephen L. Hoffman
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
| | - Daniel Carucci
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
| | - Michael R. Hollingdale
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, United States of America
| | - Eileen D. Villasante
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
| | - Thomas L. Richie
- Malaria Department, Naval Medical Research Center, Silver Spring, MD 20910, United States of America
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Bayarsaikhan G, Akbari M, Yui K, Amino R. Antigen-driven focal inflammatory death of malaria liver stages. Front Microbiol 2015; 6:47. [PMID: 25699034 PMCID: PMC4316770 DOI: 10.3389/fmicb.2015.00047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/14/2015] [Indexed: 01/24/2023] Open
Abstract
Multiple immunizations using live irradiated sporozoites, the infectious plasmodial stage delivered into the host skin during a mosquito bite, can elicit sterile immunity to malaria. CD8+ T cells seem to play an essential role in this protective immunity, since their depletion consistently abolishes sterilizing protection in several experimental models. So far, only a few parasite antigens are known to induce CD8+ T cell-dependent protection, but none of them can reach the levels of protection afforded by live attenuated parasites. Systematic attempts to identify novel antigens associated with this efficient cellular protection were so far unsuccessful. In addition, the precise mechanisms involved in the recognition and elimination of parasitized hepatocytes in vivo by CD8+ T cells still remain obscure. Recently, it has been shown that specific effector CD8+ T cells, after recognition of parasitized hepatocytes, recruit specific and non-specific activated CD8+ T cells to the site of infection, resulting in the formation of cellular clusters around and in the further elimination of intracellular parasites. The significance of this finding is discussed in the perspective of a general mechanism of antigen-dependent focalized inflammation and its consequences for the elimination of malaria liver stages.
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Affiliation(s)
- Ganchimeg Bayarsaikhan
- Unité de Biologie et Génétique du Paludisme, Département Parasites et Insectes Vecteurs, Institut Pasteur , Paris, France ; Division of Immunology, Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University , Nagasaki, Japan
| | - Masoud Akbari
- Division of Immunology, Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University , Nagasaki, Japan
| | - Katsuyuki Yui
- Division of Immunology, Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University , Nagasaki, Japan
| | - Rogerio Amino
- Unité de Biologie et Génétique du Paludisme, Département Parasites et Insectes Vecteurs, Institut Pasteur , Paris, France
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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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Chen L, Keitany GJ, Peng X, Gibson C, Mohar I, Vignali M, Crispe IN, Huang F, Wang R. Identification of pre-erythrocytic malaria antigens that target hepatocytes for killing in vivo and contribute to protection elicited by whole-parasite vaccination. PLoS One 2014; 9:e102225. [PMID: 25025375 PMCID: PMC4099202 DOI: 10.1371/journal.pone.0102225] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 06/17/2014] [Indexed: 11/19/2022] Open
Abstract
Pre-erythrocytic malaria vaccines, including those based on whole-parasite approaches, have shown protective efficacy in animal and human studies. However few pre-erythocytic antigens other than the immunodominant circumsporozoite protein (CSP) have been studied in depth with the goal of developing potent subunit malaria vaccines that are suited for use in endemic areas. Here we describe a novel technique to identify pre-erythrocytic malaria antigens that contribute to protection elicited by whole-parasite vaccination in the mouse model. Our approach combines immunization with genetically attenuated parasites and challenge with DNA plasmids encoding for potential protective pre-erythrocytic malaria antigens as luciferase fusions by hydrodynamic tail vein injection. After optimizing the technique, we first showed that immunization with Pyfabb/f−, a P. yoelii genetically attenuated parasite, induces killing of CSP-presenting hepatocytes. Depletion of CD8+ but not CD4+ T cells diminished the killing of CSP-expressing hepatocytes, indicating that killing is CD8+ T cell-dependent. Finally we showed that the use of heterologous prime/boost immunization strategies that use genetically attenuated parasites and DNA vaccines enabled the characterization of a novel pre-erythrocytic antigen, Tmp21, as a contributor to Pyfabb/f− induced protection. This technique will be valuable for identification of potentially protective liver stage antigens and has the potential to contribute to the understanding of immunity elicited by whole parasite vaccination, as well as the development of effective subunit malaria vaccines.
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Affiliation(s)
- Lin Chen
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Gladys J. Keitany
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Xiaohong Peng
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Claire Gibson
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Isaac Mohar
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Marissa Vignali
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Ian N. Crispe
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Fusheng Huang
- Department of Pathogenic Biology, Third Military Medical University, Chongqing, China
- * E-mail: (FH); (RW)
| | - Ruobing Wang
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail: (FH); (RW)
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12
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Hafalla JCR, Bauza K, Friesen J, Gonzalez-Aseguinolaza G, Hill AVS, Matuschewski K. Identification of targets of CD8⁺ T cell responses to malaria liver stages by genome-wide epitope profiling. PLoS Pathog 2013; 9:e1003303. [PMID: 23675294 PMCID: PMC3649980 DOI: 10.1371/journal.ppat.1003303] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 02/27/2013] [Indexed: 12/25/2022] Open
Abstract
CD8⁺ T cells mediate immunity against Plasmodium liver stages. However, the paucity of parasite-specific epitopes of CD8⁺ T cells has limited our current understanding of the mechanisms influencing the generation, maintenance and efficiency of these responses. To identify antigenic epitopes in a stringent murine malaria immunisation model, we performed a systematic profiling of H(2b)-restricted peptides predicted from genome-wide analysis. We describe the identification of Plasmodium berghei (Pb) sporozoite-specific gene 20 (S20)- and thrombospondin-related adhesive protein (TRAP)-derived peptides, termed PbS20₃₁₈ and PbTRAP₁₃₀ respectively, as targets of CD8⁺ T cells from C57BL/6 mice vaccinated by whole parasite strategies known to protect against sporozoite challenge. While both PbS20₃₁₈ and PbTRAP₁₃₀ elicit effector and effector memory phenotypes in both the spleens and livers of immunised mice, only PbTRAP₁₃₀-specific CD8⁺ T cells exhibit in vivo cytotoxicity. Moreover, PbTRAP₁₃₀-specific, but not PbS20₃₁₈-specific, CD8⁺ T cells significantly contribute to inhibition of parasite development. Prime/boost vaccination with PbTRAP demonstrates CD8⁺ T cell-dependent efficacy against sporozoite challenge. We conclude that PbTRAP is an immunodominant antigen during liver-stage infection. Together, our results underscore the presence of CD8⁺ T cells with divergent potencies against distinct Plasmodium liver-stage epitopes. Our identification of antigen-specific CD8⁺ T cells will allow interrogation of the development of immune responses against malaria liver stages.
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Affiliation(s)
- Julius Clemence R. Hafalla
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail: (JCRH); (KM)
| | - Karolis Bauza
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, United Kingdom
| | - Johannes Friesen
- Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Gloria Gonzalez-Aseguinolaza
- Department of Gene Therapy and Hepatology, Center for Investigation in Applied Medicine (CIMA), University of Navarra, Pamplona, Spain
| | - Adrian V. S. Hill
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, United Kingdom
| | - Kai Matuschewski
- Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
- Institute of Biology, Humboldt University, Berlin, Germany
- * E-mail: (JCRH); (KM)
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13
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Duffy PE, Sahu T, Akue A, Milman N, Anderson C. Pre-erythrocytic malaria vaccines: identifying the targets. Expert Rev Vaccines 2013; 11:1261-80. [PMID: 23176657 DOI: 10.1586/erv.12.92] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pre-erythrocytic malaria vaccines target Plasmodium during its sporozoite and liver stages, and can prevent progression to blood-stage disease, which causes a million deaths each year. Whole organism sporozoite vaccines induce sterile immunity in animals and humans and guide subunit vaccine development. A recombinant protein-in-adjuvant pre-erythrocytic vaccine called RTS,S reduces clinical malaria without preventing infection in field studies and additional antigens may be required to achieve sterile immunity. Although few vaccine antigens have progressed to human testing, new insights into parasite biology, expression profiles and immunobiology have offered new targets for intervention. Future advances require human trials of additional antigens, as well as platforms to induce the durable antibody and cellular responses including CD8(+) T cells that contribute to sterile protection.
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Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology & Vaccinology, Division of Intramural Research, NIAID, NIH, Rockville, MD, USA.
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A T-cell response to a liver-stage Plasmodium antigen is not boosted by repeated sporozoite immunizations. Proc Natl Acad Sci U S A 2013; 110:6055-60. [PMID: 23530242 DOI: 10.1073/pnas.1303834110] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Development of an antimalarial subunit vaccine inducing protective cytotoxic T lymphocyte (CTL)-mediated immunity could pave the way for malaria eradication. Experimental immunization with sporozoites induces this type of protective response, but the extremely large number of proteins expressed by Plasmodium parasites has so far prohibited the identification of sufficient discrete T-cell antigens to develop subunit vaccines that produce sterile immunity. Here, using mice singly immunized with Plasmodium yoelii sporozoites and high-throughput screening, we identified a unique CTL response against the parasite ribosomal L3 protein. Unlike CTL responses to the circumsporozoite protein (CSP), the population of L3-specific CTLs was not expanded by multiple sporozoite immunizations. CSP is abundant in the sporozoite itself, whereas L3 expression does not increase until the liver stage. The response induced by a single immunization with sporozoites reduces the parasite load in the liver so greatly during subsequent immunizations that L3-specific responses are only generated during the primary exposure. Functional L3-specific CTLs can, however, be expanded by heterologous prime-boost regimens. Thus, although repeat sporozoite immunization expands responses to preformed antigens like CSP that are present in the sporozoite itself, this immunization strategy may not expand CTLs targeting parasite proteins that are synthesized later. Heterologous strategies may be needed to increase CTL responses across the entire spectrum of Plasmodium liver-stage proteins.
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Nganou-Makamdop K, van Roosmalen ML, Audouy SAL, van Gemert GJ, Leenhouts K, Hermsen CC, Sauerwein RW. Bacterium-like particles as multi-epitope delivery platform for Plasmodium berghei circumsporozoite protein induce complete protection against malaria in mice. Malar J 2012; 11:50. [PMID: 22348325 PMCID: PMC3337279 DOI: 10.1186/1475-2875-11-50] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 02/20/2012] [Indexed: 12/17/2022] Open
Abstract
Background Virus-like particles have been regularly used as an antigen delivery system for a number of Plasmodium peptides or proteins. The present study reports the immunogenicity and protective efficacy of bacterium-like particles (BLPs) generated from Lactococcus lactis and loaded with Plasmodium berghei circumsporozoite protein (PbCSP) peptides. Methods A panel of BLP-PbCSP formulations differing in composition and quantity of B-cell, CD4+ and CD8+ T-cell epitopes of PbCSP were tested in BALB/c mice. Results BLP-PbCSP1 induced specific humoral responses but no IFN-γ ELISPOT response, protecting 30-40% of the immunized mice. BLP-PbCSP2, with reduced length of the non-immunogenic part of the T-cell-epitopes construct, increased induction of IFN-γ responses as well as protection up to 60-70%. Compared to controls, lower parasitaemia was observed in unprotected mice immunized with BLP-PbCSP1 or 2, suggestive for partial immunity. Finally, further increase of the number of B-cell epitopes and codon optimization (BLP-PbCSP4) induced the highest anti-CSP antibody levels and number of IFN-γ spots, resulting in sterile immunity in 100% of the immunized mice. Conclusion Presentation of Plasmodium-derived antigens using BLPs as a delivery system induced complete protection in a murine malaria model. Eventually, BLPs have the potential to be used as a novel versatile delivery platform in malaria vaccine development.
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Affiliation(s)
- Krystelle Nganou-Makamdop
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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A New Method to Determine Antigen-Specific CD8+ T Cell Activity in Vivo by Hydrodynamic Injection. Biomolecules 2012; 2:23-33. [PMID: 24970125 PMCID: PMC4030865 DOI: 10.3390/biom2010023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 12/30/2011] [Accepted: 01/01/2012] [Indexed: 01/23/2023] Open
Abstract
Hydrodynamic tail vein (HTV) delivery is a simple and rapid tail vein injection method of a high volume of naked plasmid DNA resulting in high levels of foreign gene expression in organs, especially the liver. Compared to other organs, HTV delivery results in more than a 1000-fold higher transgene expression in liver. After being bitten by malaria-infected mosquitoes, malaria parasites transiently infect the host liver and form the liver stages. The liver stages are known to be the key target for CD8+ T cells that mediate protective anti-malaria immunity in an animal model. Therefore, in this study, we utilized the HTV delivery technique as a tool to determine the in vivo cytotoxic effect of malaria antigen-specific CD8+ T cells. Two weeks after mice were immunized with recombinant adenoviruses expressing malarial antigens, the immunized mice as well as naïve mice were challenged by HTV delivery of naked plasmid DNA co-encoding respective antigen together with luciferase using dual promoters. Three days after the HTV challenge, non-invasive whole-body bioluminescent imaging was performed. The images demonstrate in vivo activity of CD8+ T cells against malaria antigen-expressing cells in liver.
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