1
|
Abstract
Cholera is a severe diarrheal disease caused by the bacterium Vibrio cholerae and constitutes a significant public health threat in many areas of the world. V. cholerae infection elicits potent and long-lasting immunity, and efforts to develop cholera vaccines have been ongoing for more than a century. Currently available inactivated two-dose oral cholera vaccines are increasingly deployed to both prevent and actively curb cholera outbreaks, and they are key components of the global effort to eradicate cholera. However, these killed whole-cell vaccines have several limitations, and a variety of new oral and nonoral cholera vaccine platforms have recently been developed. Here, we review emerging concepts in cholera vaccine design and implementation that have been driven by insights from human and animal studies. As a prototypical vaccine-preventable disease, cholera continues to be an excellent target for the development and application of cutting-edge technologies and platforms that may transform vaccinology. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Brandon Sit
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA; .,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Bolutife Fakoya
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA; .,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew K Waldor
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA; .,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA.,Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Massachusetts, USA.,Howard Hughes Medical Institute, Bethesda, Maryland, USA
| |
Collapse
|
2
|
Fakoya B, Hullahalli K, Rubin DHF, Leitner DR, Chilengi R, Sack DA, Waldor MK. Nontoxigenic Vibrio cholerae Challenge Strains for Evaluating Vaccine Efficacy and Inferring Mechanisms of Protection. mBio 2022; 13:e0053922. [PMID: 35389261 PMCID: PMC9040834 DOI: 10.1128/mbio.00539-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 12/24/2022] Open
Abstract
Human challenge studies are instrumental for testing cholera vaccines, but these studies use outdated strains and require inpatient facilities. Here, we created next-generation isogenic Ogawa and Inaba O1 V. cholerae challenge strains (ZChol strains) derived from a contemporary Zambian clinical isolate representative of current dominant pandemic V. cholerae. Since the primary mechanism of immune protection against cholera is thought to be antibody responses that limit V. cholerae colonization and not the diarrheagenic actions of cholera toxin, these strains were rendered nontoxigenic. In infant mice, the ZChol strains did not cause diarrhea and proved to accurately gauge reduction in intestinal colonization mediated by effective vaccination. ZChol strains were also valuable as targets for measuring vibriocidal antibody responses. Using barcoded ZChol strains, we discovered that vaccination and passive immunity in the infant mouse model tightens the infection bottleneck without restricting pathogen expansion during intestinal infection. Collectively, our findings suggest that ZChol strains have the potential to enhance the safety, relevance, and scope of future cholera vaccine challenge studies and be valuable reagents for studies of immunity to cholera. IMPORTANCE Human challenge studies are a valuable method for testing the efficacy of cholera vaccines. However, challenge studies cannot be performed in countries of cholera endemicity due to safety concerns; also, contemporary pandemic Vibrio cholerae strains are not used in current challenge studies. To facilitate cholera research, we derived nontoxigenic challenge strains of both V. cholerae serotypes from a 2016 clinical isolate from Zambia and demonstrated how they can be used to gauge cholera immunity accurately and safely. These strains were also genetically barcoded, adding the potential for analyses of V. cholerae population dynamics to challenge studies. Preclinical analyses presented here suggest that these strains have the potential to enhance the safety, relevance, and scope of future cholera vaccine challenge studies and be valuable reagents for studies of immunity to cholera.
Collapse
Affiliation(s)
- Bolutife Fakoya
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Bethesda, Maryland, USA
| | - Karthik Hullahalli
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Bethesda, Maryland, USA
| | - Daniel H. F. Rubin
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Bethesda, Maryland, USA
| | - Deborah R. Leitner
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Bethesda, Maryland, USA
| | - Roma Chilengi
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - David A. Sack
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Matthew K. Waldor
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Bethesda, Maryland, USA
| |
Collapse
|
3
|
Sit B, Fakoya B, Waldor MK. Animal models for dissecting Vibrio cholerae intestinal pathogenesis and immunity. Curr Opin Microbiol 2022; 65:1-7. [PMID: 34695646 PMCID: PMC8792189 DOI: 10.1016/j.mib.2021.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/14/2021] [Accepted: 09/20/2021] [Indexed: 02/03/2023]
Abstract
The human diarrheal disease cholera is caused by the bacterium Vibrio cholerae. Efforts to develop animal models that closely mimic cholera to study the pathogenesis of this disease began >125 years ago. Here, we review currently used non-surgical, oral inoculation-based animal models for investigation of V. cholerae intestinal colonization and disease and highlight recent discoveries that have illuminated mechanisms of cholera pathogenesis and immunity, particularly in the area of how V. cholerae interacts with the gut microbiome to influence infection. The emergence of high-throughput tools for studies of pathogen-host interactions, along with continued advances in host genetic engineering and manipulation in animal models of V. cholerae will deepen understanding of cholera pathogenesis, uncovering knowledge important for control of this globally important bacterial pathogen.
Collapse
Affiliation(s)
- Brandon Sit
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, Massachusetts, USA,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Bolutife Fakoya
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, Massachusetts, USA,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew K. Waldor
- Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, Massachusetts, USA,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA,Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Massachusetts, USA,Howard Hughes Medical Institute, Bethesda, Maryland, USA,corresponding author: , Phone: 6175254646, Address: MCP-759, 181 Longwood Avenue, Boston, Massachusetts, USA 02115
| |
Collapse
|
4
|
Dissecting serotype-specific contributions to live oral cholera vaccine efficacy. Proc Natl Acad Sci U S A 2021; 118:2018032118. [PMID: 33558237 DOI: 10.1073/pnas.2018032118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The O1 serogroup of Vibrio cholerae causes pandemic cholera and is divided into the Ogawa and Inaba serotypes. The O-antigen is V. cholerae's immunodominant antigen, and the two serotypes, which differ by the presence or absence of a terminally methylated O-antigen, likely influence development of immunity to cholera and oral cholera vaccines (OCVs). However, there is no consensus regarding the relative immunological potency of each serotype, in part because previous studies relied on genetically heterogeneous strains. Here, we engineered matched serotype variants of a live OCV candidate, HaitiV, and used a germfree mouse model to evaluate the immunogenicity and protective efficacy of each vaccine serotype. By combining vibriocidal antibody quantification with single- and mixed-strain infection assays, we found that all three HaitiV variants-InabaV, OgawaV, and HikoV (bivalent Inaba/Ogawa)-were immunogenic and protective. None of the vaccine serotypes were superior across both of these vaccine metrics, suggesting that the impact of O1-serotype variation in OCV design, although detectable, is subtle. However, all three live vaccines significantly outperformed formalin-killed HikoV, supporting the idea that live OCV usage will bolster current cholera control practices. The potency of OCVs was found to be challenge strain-dependent, emphasizing the importance of appropriate strain selection for cholera challenge studies. Our findings and experimental approaches will be valuable for guiding the development of live OCVs and oral vaccines for additional pathogens.
Collapse
|
5
|
Cho JY, Liu R, Macbeth JC, Hsiao A. The Interface of Vibrio cholerae and the Gut Microbiome. Gut Microbes 2021; 13:1937015. [PMID: 34180341 PMCID: PMC8244777 DOI: 10.1080/19490976.2021.1937015] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 02/04/2023] Open
Abstract
The bacterium Vibrio cholerae is the etiologic agent of the severe human diarrheal disease cholera. The gut microbiome, or the native community of microorganisms found in the human gastrointestinal tract, is increasingly being recognized as a factor in driving susceptibility to infection, in vivo fitness, and host interactions of this pathogen. Here, we review a subset of the emerging studies in how gut microbiome structure and microbial function are able to drive V. cholerae virulence gene regulation, metabolism, and modulate host immune responses to cholera infection and vaccination. Improved mechanistic understanding of commensal-pathogen interactions offers new perspectives in the design of prophylactic and therapeutic approaches for cholera control.
Collapse
Affiliation(s)
- Jennifer Y. Cho
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
- Department of Biochemistry, University of California, Riverside, California, USA
| | - Rui Liu
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
- Graduate Program in Genetics, Genomics, and Bioinformatics, University of California, Riverside, California, USA
| | - John C. Macbeth
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Ansel Hsiao
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
| |
Collapse
|