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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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Kamau E, Chaudhury S, Bolton JS, Slike BM, Jian N, Eller MA, Eller LA, Ake J, Robb ML, Krebs SJ, Bergmann-Leitner ES. Susceptibility to HIV-1 Acquisition linked to Malaria Exposure: A Case-control Study. Clin Infect Dis 2022; 75:1834-1837. [PMID: 35594548 DOI: 10.1093/cid/ciac384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Indexed: 11/13/2022] Open
Abstract
HIV and malaria infection rates overlap across sub-Saharan Africa, but factors influencing their co-occurrence are unclear. In a case-control study, we investigated whether malaria exposure increases risk of HIV-1 acquisition. Prior to seroconverting, HIV-positive cases had significantly higher malaria-associated antibodies compared to HIV-negative controls, linking malaria exposure to HIV-1 acquisition.
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Affiliation(s)
- Edwin Kamau
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Sidhartha Chaudhury
- Center for Enabling Capabilities, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Jessica S Bolton
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.,Biologics Research and Development, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Bonnie M Slike
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Ningbo Jian
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Michael A Eller
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Leigh Anne Eller
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Julie Ake
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Merlin L Robb
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Shelly J Krebs
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Elke S Bergmann-Leitner
- Biologics Research and Development, Walter Reed Army Institute of Research, Silver Spring, MD, USA
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