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Bolton JS, MacGill RS, Locke E, Regules JA, Bergmann-Leitner ES. Novel antibody competition binding assay identifies distinct serological profiles associated with protection. Front Immunol 2023; 14:1303446. [PMID: 38152401 PMCID: PMC10752609 DOI: 10.3389/fimmu.2023.1303446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 11/21/2023] [Indexed: 12/29/2023] Open
Abstract
Introduction Pre-erythrocytic malaria vaccines hold the promise of inducing sterile protection thereby preventing the morbidity and mortality associated with Plasmodium infection. The main surface antigen of P. falciparum sporozoites, i.e., the circumsporozoite protein (CSP), has been extensively explored as a target of such vaccines with significant success in recent years. Systematic adjuvant selection, refinements of the immunization regimen, and physical properties of the antigen may all contribute to the potential of increasing the efficacy of CSP-based vaccines. Protection appears to be dependent in large part on CSP antibodies. However due to a knowledge gap related to the exact correlates of immunity, there is a critical need to improve our ability to down select candidates preclinically before entering clinical trials including with controlled human malaria infections (CHMI). Methods We developed a novel multiplex competition assay based on well-characterized monoclonal antibodies (mAbs) that target crucial epitopes across the CSP molecule. This new tool assesses both, quality and epitope-specific concentrations of vaccine-induced antibodies by measuring their equivalency with a panel of well-characterized, CSP-epitope-specific mAbs. Results Applying this method to RTS,S-immune sera from a CHMI trial demonstrated a quantitative epitope-specificity profile of antibody responses that can differentiate between protected vs. nonprotected individuals. Aligning vaccine efficacy with quantitation of the epitope fine specificity results of this equivalency assay reveals the importance of epitope specificity. Discussion The newly developed serological equivalence assay will inform future vaccine design and possibly even adjuvant selection. This methodology can be adapted to other antigens and disease models, when a panel of relevant mAbs exists, and could offer a unique tool for comparing and down-selecting vaccine formulations.
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Affiliation(s)
- Jessica S. Bolton
- Biologics Research & Development, Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD, United States
| | - Randall S. MacGill
- Center for Vaccine Innovation and Access, PATH, Washington, DC, United States
| | - Emily Locke
- Center for Vaccine Innovation and Access, PATH, Washington, DC, United States
| | - Jason A. Regules
- Biologics Research & Development, Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD, United States
| | - Elke S. Bergmann-Leitner
- Biologics Research & Development, Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD, United States
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2
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Genito CJ, Brooks K, Smith A, Ryan E, Soto K, Li Y, Warter L, Dutta S. Protective antibody threshold of RTS,S/AS01 malaria vaccine correlates antigen and adjuvant dose in mouse model. NPJ Vaccines 2023; 8:114. [PMID: 37563255 PMCID: PMC10415390 DOI: 10.1038/s41541-023-00714-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023] Open
Abstract
Mouse models are useful for the early down-selection of malaria vaccine candidates. The Walter Reed Army Institute of Research has optimized a transgenic Plasmodium berghei sporozoite challenge model to compare the efficacy of Plasmodium falciparum circumsporozoite protein (CSP) vaccines. GSK's RTS,S vaccine formulated in the adjuvant AS01 can protect malaria-naïve individuals against malaria. We report that the RTS,S/AS01 vaccine induces high level sterile protection in our mouse model. Down titration of the antigen at a constant AS01 dose revealed a potent antigen dose-sparing effect and the superiority of RTS,S/AS01 over a soluble CSP antigen. RTS,S-mediated protective immunity was associated with a threshold of major repeat antibody titer. Combined titration of the antigen and adjuvant showed that reducing the adjuvant could improve antibody boosting post-3rd vaccination and reduce the threshold antibody concentration required for protection. Mouse models can provide a pathway for preclinical assessment of strategies to improve CSP vaccines against malaria.
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Affiliation(s)
- Christopher J Genito
- Structural Vaccinology Laboratory, Biologics Research and Development Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Katherine Brooks
- Structural Vaccinology Laboratory, Biologics Research and Development Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Alexis Smith
- Structural Vaccinology Laboratory, Biologics Research and Development Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Emma Ryan
- Structural Vaccinology Laboratory, Biologics Research and Development Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Kim Soto
- Structural Vaccinology Laboratory, Biologics Research and Development Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Yuanzhang Li
- Center for Enabling Capabilities, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | | | - Sheetij Dutta
- Structural Vaccinology Laboratory, Biologics Research and Development Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA.
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3
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Odongo K, Hironao KY, Yamashita Y, Ashida H. Development of sandwich ELISAs for detecting glucagon-like peptide-1 secretion from intestinal L-cells and their application in STC-1 cells and mice. J Clin Biochem Nutr 2023; 72:28-38. [PMID: 36777078 PMCID: PMC9899920 DOI: 10.3164/jcbn.22-78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 09/03/2022] [Indexed: 11/05/2022] Open
Abstract
Certain nutrients stimulate glucagon-like peptide-1 (GLP-1) secretion from the intestinal enteroendocrine L-cells, but due to rapid degradation by the DPP-4 enzyme, >90% is converted to inactive metabolite before reaching the target organs via circulation. Plants are a source of potent bioactive compounds that promote endogenous secretion of GLP-1 from L-cells. To search for the effective bioactive compound from a vast library of natural compounds, a reliable and low-cost assay is required considering the high cost of commercial assays. We developed a low-cost sandwich enzyme-linked immunosorbent assays (s-ELISAs) for detecting 'total', 'sensitive active', and 'wide-range active' GLP-1. The s-ELISAs exhibited high sensitivity with measurement ranges between 0.94~240, 0.98~62.5, and 4.8~4,480 pmol/L, respectively. High precision was observed; i.e., CVs within 5% and 20% for intra- and inter-assay variations, respectively, and excellent recovery of exogenous GLP-1 from assay buffer. The developed s-ELISAs had the same performance as the commercial kits and approximately 80% cheaper cost. For their application, cinnamtannin A2-induced GLP-1 secretion was confirmed in STC-1 cells consistent with our previous findings. The s-ELISAs were further validated by measuring plasma GLP-1 level in mice after oral administration of black soy bean seed coat extract containing cinnamtannin A2.
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Affiliation(s)
- Kevin Odongo
- Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Ken-yu Hironao
- Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Yoko Yamashita
- Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Hitoshi Ashida
- Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan,To whom correspondence should be addressed. E-mail:
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4
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Young WC, Carpp LN, Chaudhury S, Regules JA, Bergmann-Leitner ES, Ockenhouse C, Wille-Reece U, deCamp AC, Hughes E, Mahoney C, Pallikkuth S, Pahwa S, Dennison SM, Mudrak SV, Alam SM, Seaton KE, Spreng RL, Fallon J, Michell A, Ulloa-Montoya F, Coccia M, Jongert E, Alter G, Tomaras GD, Gottardo R. Comprehensive Data Integration Approach to Assess Immune Responses and Correlates of RTS,S/AS01-Mediated Protection From Malaria Infection in Controlled Human Malaria Infection Trials. Front Big Data 2021; 4:672460. [PMID: 34212134 PMCID: PMC8239149 DOI: 10.3389/fdata.2021.672460] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/27/2021] [Indexed: 12/13/2022] Open
Abstract
RTS,S/AS01 (GSK) is the world’s first malaria vaccine. However, despite initial efficacy of almost 70% over the first 6 months of follow-up, efficacy waned over time. A deeper understanding of the immune features that contribute to RTS,S/AS01-mediated protection could be beneficial for further vaccine development. In two recent controlled human malaria infection (CHMI) trials of the RTS,S/AS01 vaccine in malaria-naïve adults, MAL068 and MAL071, vaccine efficacy against patent parasitemia ranged from 44% to 87% across studies and arms (each study included a standard RTS,S/AS01 arm with three vaccine doses delivered in four-week-intervals, as well as an alternative arm with a modified version of this regimen). In each trial, RTS,S/AS01 immunogenicity was interrogated using a broad range of immunological assays, assessing cellular and humoral immune parameters as well as gene expression. Here, we used a predictive modeling framework to identify immune biomarkers measured at day-of-challenge that could predict sterile protection against malaria infection. Using cross-validation on MAL068 data (either the standard RTS,S/AS01 arm alone, or across both the standard RTS,S/AS01 arm and the alternative arm), top-performing univariate models identified variables related to Fc effector functions and titer of antibodies that bind to the central repeat region (NANP6) of CSP as the most predictive variables; all NANP6-related variables consistently associated with protection. In cross-study prediction analyses of MAL071 outcomes (the standard RTS,S/AS01 arm), top-performing univariate models again identified variables related to Fc effector functions of NANP6-targeting antibodies as highly predictive. We found little benefit–with this dataset–in terms of improved prediction accuracy in bivariate models vs. univariate models. These findings await validation in children living in malaria-endemic regions, and in vaccinees administered a fourth RTS,S/AS01 dose. Our findings support a “quality as well as quantity” hypothesis for RTS,S/AS01-elicited antibodies against NANP6, implying that malaria vaccine clinical trials should assess both titer and Fc effector functions of anti-NANP6 antibodies.
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Affiliation(s)
- William Chad Young
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Lindsay N Carpp
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Sidhartha Chaudhury
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Jason A Regules
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Elke S Bergmann-Leitner
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | | | | | - Allan C deCamp
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Ellis Hughes
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Celia Mahoney
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Suresh Pallikkuth
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Savita Pahwa
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - S Moses Dennison
- Center for Human Systems Immunology, Duke University, Durham, NC, United States.,Departments of Surgery, Immunology, and Molecular Genetics and Microbiology, Duke University, Durham, NC, United States.,Duke Human Vaccine Institute, Duke University, Durham, NC, United States
| | - Sarah V Mudrak
- Center for Human Systems Immunology, Duke University, Durham, NC, United States.,Departments of Surgery, Immunology, and Molecular Genetics and Microbiology, Duke University, Durham, NC, United States.,Duke Human Vaccine Institute, Duke University, Durham, NC, United States
| | - S Munir Alam
- Center for Human Systems Immunology, Duke University, Durham, NC, United States.,Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Pathology, Duke University, Durham, NC, United States
| | - Kelly E Seaton
- Center for Human Systems Immunology, Duke University, Durham, NC, United States.,Departments of Surgery, Immunology, and Molecular Genetics and Microbiology, Duke University, Durham, NC, United States.,Duke Human Vaccine Institute, Duke University, Durham, NC, United States
| | - Rachel L Spreng
- Center for Human Systems Immunology, Duke University, Durham, NC, United States.,Departments of Surgery, Immunology, and Molecular Genetics and Microbiology, Duke University, Durham, NC, United States.,Duke Human Vaccine Institute, Duke University, Durham, NC, United States
| | - Jon Fallon
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States
| | - Ashlin Michell
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States
| | | | | | | | - Galit Alter
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States
| | - Georgia D Tomaras
- Center for Human Systems Immunology, Duke University, Durham, NC, United States.,Departments of Surgery, Immunology, and Molecular Genetics and Microbiology, Duke University, Durham, NC, United States.,Duke Human Vaccine Institute, Duke University, Durham, NC, United States
| | - Raphael Gottardo
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
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5
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Kurtovic L, Atre T, Feng G, Wines BD, Chan JA, Boyle MJ, Drew DR, Hogarth PM, Fowkes FJI, Bergmann-Leitner ES, Beeson JG. Multi-functional antibodies are induced by the RTS,S malaria vaccine and associated with protection in a phase I/IIa trial. J Infect Dis 2020; 224:1128-1138. [PMID: 32236404 PMCID: PMC8514181 DOI: 10.1093/infdis/jiaa144] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/30/2020] [Indexed: 01/24/2023] Open
Abstract
Background RTS,S is the leading malaria vaccine candidate but only confers partial efficacy against malaria in children. RTS,S is based on the major Plasmodium falciparum sporozoite surface antigen, circumsporozoite protein (CSP). The induction of anti-CSP antibodies is important for protection; however, it is unclear how these protective antibodies function. Methods We quantified the induction of functional anti-CSP antibody responses in healthy malaria-naive adults (N = 45) vaccinated with RTS,S/AS01. This included the ability to mediate effector functions via the fragment crystallizable (Fc) region, such as interacting with human complement proteins and Fcγ-receptors (FcγRs) that are expressed on immune cells, which promote various immunological functions. Results Our major findings were (1) RTS,S-induced antibodies mediated Fc-dependent effector functions, (2) functional antibodies were generally highest after the second vaccine dose, (3) functional antibodies targeted multiple regions of CSP, (4) participants with higher levels of functional antibodies had a reduced probability of developing parasitemia following homologous challenge (P < .05), and (5) nonprotected subjects had higher levels of anti-CSP IgM. Conclusions Our data suggest a role for Fc-dependent antibody effector functions in RTS,S-induced immunity. Enhancing the induction of these functional activities may be a strategy to improve the protective efficacy of RTS,S or other malaria vaccines. Clinical Trials Registration NCT00075049
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Affiliation(s)
- Liriye Kurtovic
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Tanmaya Atre
- Malaria Vaccine Branch, US Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, United States
| | | | - Bruce D Wines
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Clinical Pathology, The University of Melbourne, Melbourne, Australia
| | - Jo-Anne Chan
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Michelle J Boyle
- Burnet Institute, Melbourne, Australia.,QIMR Berghofer, Herston, Australia
| | | | - P Mark Hogarth
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Clinical Pathology, The University of Melbourne, Melbourne, Australia
| | - Freya J I Fowkes
- Burnet Institute, Melbourne, Australia.,Department of Epidemiology and Preventative Medicine and Department of Infectious Diseases, Monash University, Melbourne, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Elke S Bergmann-Leitner
- Malaria Vaccine Branch, US Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, United States
| | - James G Beeson
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Microbiology, Monash University, Clayton, Australia.,Department of Medicine, The University of Melbourne, Parkville, Australia
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6
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Amelia F, Iyori M, Emran TB, Yamamoto DS, Genshi K, Otsuka H, Onoue Y, Yusuf Y, Islam A, Yoshida S. Down-selecting circumsporozoite protein-based malaria vaccine: A comparison of malaria sporozoite challenge model. Parasite Immunol 2020; 41:e12624. [PMID: 30883819 DOI: 10.1111/pim.12624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/28/2019] [Accepted: 03/08/2019] [Indexed: 12/18/2022]
Abstract
Plasmodium falciparum circumsporozoite protein (PfCSP) is the main target antigen in development of pre-erythrocytic malaria vaccines. To evaluate PfCSP vaccines in animal models, challenge by intravenous sporozoite injection is preferentially used. However, in clinical trials, vaccinated human volunteers are exposed to the bites of malaria-infected mosquitoes. In this study, we down-selected Escherichia coli-produced full-length PfCSP (PfCSP-F) and its three truncated PfCSPs based on their abilities to elicit immune response and protection in mice against two challenge models. We showed that immunization with three doses of PfCSP-F elicited high anti-PfCSP antibody titres and 100% protection against the bites of infected mosquitoes. Meanwhile, three-dose truncated PfCSP induced 60%-70% protection after immunization with each truncated PfCSP. Heterologous prime-boost immunization regimen with adenovirus-PfCSP-F and R32LR greatly induced complete protection against intravenous sporozoite injection. Our results suggest that Abs to both anti-repeat and anti-nonrepeat regions induced by PfCSP-F are required to confer complete protection against challenge by the bites of infected mosquitoes, whereas anti-repeat Abs play an important role in protection against intravenous sporozoite injection. Our findings provide a potential clinical application that PfCSP-F vaccine induces potent Abs capable of neutralizing sporozoites in the dermis inoculated by infected mosquitoes and subsequently sporozoites in the blood circulation.
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Affiliation(s)
- Fitri Amelia
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan.,Department of Chemistry, Universitas Negeri Padang, Padang, Indonesia
| | - Mitsuhiro Iyori
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Talha Bin Emran
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Daisuke S Yamamoto
- Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, Japan
| | - Kento Genshi
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Hiromu Otsuka
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Yutaro Onoue
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Yenni Yusuf
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Ashekul Islam
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Shigeto Yoshida
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
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7
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Dennison SM, Reichartz M, Seaton KE, Dutta S, Wille-Reece U, Hill AVS, Ewer KJ, Rountree W, Sarzotti-Kelsoe M, Ozaki DA, Alam SM, Tomaras GD. Qualified Biolayer Interferometry Avidity Measurements Distinguish the Heterogeneity of Antibody Interactions with Plasmodium falciparum Circumsporozoite Protein Antigens. THE JOURNAL OF IMMUNOLOGY 2018; 201:1315-1326. [PMID: 30006374 PMCID: PMC6077849 DOI: 10.4049/jimmunol.1800323] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/12/2018] [Indexed: 01/09/2023]
Abstract
Ab avidity is a measure of the overall strength of Ab–Ag interactions and hence is important for understanding the functional efficiency of Abs. In vaccine evaluations, Ab avidity measurements can provide insights into immune correlates of protection and generate hypotheses regarding mechanisms of protection to improve vaccine design to achieve higher levels of efficacy. The commonly used Ab avidity assays require the use of chaotropic reagents to measure avidity index. In this study, using real-time detection of Ab–Ag binding by biolayer interferometry (BLI) technique, we have developed a qualified assay for measuring avidity of vaccine-induced Abs specific for Plasmodium falciparum circumsporozoite protein (CSP) Ags. Human mAb derived from plasmablasts of recipients of RTS,S/AS01 (RTS,S), the most advanced malaria vaccine candidate, were used in the assay development to measure Ag-specific binding responses and rate constants of association and dissociation. The optimized BLI binding assay demonstrated 1) good precision (percentage of coefficient of variation <20), 2) high specificity, 3) a lower limit of detection and quantitation in the 0.3–3.3 nM range, and 4) a range of linearity up to 50–100 nM for the CSP Ags tested. Analysis of polyclonal sera of malaria vaccinees demonstrated the suitability of this method to distinguish among vaccinees and rank Ab responses by avidity. These results demonstrate that precise, specific, and sensitive BLI measurements of Ab avidity in polyclonal sera from malaria vaccinees can map Ab response heterogeneity and potentially help to determine the role of Ab avidity as an immune correlate of protection for vaccines.
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Affiliation(s)
- S Moses Dennison
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710;
| | | | - Kelly E Seaton
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710
| | - Sheetij Dutta
- Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | | | | | - Katie J Ewer
- The Jenner Institute, Oxford OX3 7DQ, United Kingdom
| | - Wes Rountree
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710
| | - Marcella Sarzotti-Kelsoe
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710.,Department of Surgery, Duke University, Durham, NC 27710.,Department of Immunology, Duke University, Durham, NC 27710
| | - Daniel A Ozaki
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710.,Department of Surgery, Duke University, Durham, NC 27710
| | - S Munir Alam
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710.,Department of Pathology, Duke University, Durham, NC 27710; and
| | - Georgia D Tomaras
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710; .,Department of Surgery, Duke University, Durham, NC 27710.,Department of Immunology, Duke University, Durham, NC 27710.,Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710
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8
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Human antibodies activate complement against Plasmodium falciparum sporozoites, and are associated with protection against malaria in children. BMC Med 2018; 16:61. [PMID: 29706136 PMCID: PMC5925837 DOI: 10.1186/s12916-018-1054-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 04/10/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Antibodies targeting Plasmodium falciparum sporozoites play a key role in human immunity to malaria. However, antibody mechanisms that neutralize sporozoites are poorly understood. This has been a major constraint in developing highly efficacious vaccines, as we lack strong correlates of protective immunity. METHODS We quantified the ability of human antibodies from malaria-exposed populations to interact with human complement, examined the functional effects of complement activity against P. falciparum sporozoites in vitro, and identified targets of functional antibodies. In children and adults from malaria-endemic regions, we determined the acquisition of complement-fixing antibodies to sporozoites and their relationship with antibody isotypes and subclasses. We also investigated associations with protective immunity in a longitudinal cohort of children (n = 206) residing in a malaria-endemic region. RESULTS We found that antibodies to the major sporozoite surface antigen, circumsporozoite protein (CSP), were predominately IgG1, IgG3, and IgM, and could interact with complement through recruitment of C1q and activation of the classical pathway. The central repeat region of CSP, included in leading vaccines, was a key target of complement-fixing antibodies. We show that antibodies activate human complement on P. falciparum sporozoites, which consequently inhibited hepatocyte cell traversal that is essential for establishing liver-stage infection, and led to sporozoite death in vitro. The natural acquisition of complement-fixing antibodies in malaria-exposed populations was age-dependent, and was acquired more slowly to sporozoite antigens than to merozoite antigens. In a longitudinal cohort of children, high levels of complement-fixing antibodies were significantly associated with protection against clinical malaria. CONCLUSIONS These novel findings point to complement activation by antibodies as an important mechanism of anti-sporozoite human immunity, thereby enabling new strategies for developing highly efficacious malaria vaccines. We also present evidence that complement-fixing antibodies may be a valuable correlate of protective immunity in humans.
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9
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Cabral-Miranda G, Heath MD, Gomes AC, Mohsen MO, Montoya-Diaz E, Salman AM, Atcheson E, Skinner MA, Kramer MF, Reyes-Sandoval A, Bachmann MF. Microcrystalline Tyrosine (MCT ®): A Depot Adjuvant in Licensed Allergy Immunotherapy Offers New Opportunities in Malaria. Vaccines (Basel) 2017; 5:vaccines5040032. [PMID: 28953265 PMCID: PMC5748599 DOI: 10.3390/vaccines5040032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 08/25/2017] [Accepted: 09/20/2017] [Indexed: 02/07/2023] Open
Abstract
Microcrystalline Tyrosine (MCT®) is a widely used proprietary depot excipient in specific immunotherapy for allergy. In the current study we assessed the potential of MCT to serve as an adjuvant in the development of a vaccine against malaria. To this end, we formulated the circumsporozoite protein (CSP) of P. vivax in MCT and compared the induced immune responses to CSP formulated in PBS or Alum. Both MCT and Alum strongly increased immunogenicity of CSP compared to PBS in both C57BL/6 and BALB/c mice. Challenge studies in mice using a chimeric P. bergei expressing CSP of P. vivax demonstrated clinically improved symptoms of malaria with CSP formulated in both MCT and Alum; protection was, however, more pronounced if CSP was formulated in MCT. Hence, MCT may be an attractive biodegradable adjuvant useful for the development of novel prophylactic vaccines.
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Affiliation(s)
- Gustavo Cabral-Miranda
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
| | - Matthew D Heath
- Allergy Therapeutics (UK) Ltd. Dominion Way, Worthing BN14 8SA, UK.
| | - Ariane C Gomes
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
| | - Mona O Mohsen
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
| | - Eduardo Montoya-Diaz
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
| | - Ahmed M Salman
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
| | - Erwan Atcheson
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
| | - Murray A Skinner
- Allergy Therapeutics (UK) Ltd. Dominion Way, Worthing BN14 8SA, UK.
| | | | - Arturo Reyes-Sandoval
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
| | - Martin F Bachmann
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford OX3 7BN, UK.
- Immunology, RIA, Inselspital, University of Bern, 3010 Bern ,Switzerland.
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