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De-Simone SG, Napoleão-Pêgo P, Gonçalves PS, Lechuga GC, Cardoso SV, Provance DW, Morel CM, da Silva FR. B-Cell Epitope Mapping of the Vibrio cholera Toxins A, B, and P and an ELISA Assay. Int J Mol Sci 2022; 24:531. [PMID: 36613974 PMCID: PMC9820764 DOI: 10.3390/ijms24010531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/31/2022] Open
Abstract
Oral immunization with the choleric toxin (CT) elicits a high level of protection against its enterotoxin activities and can control cholera in endemic settings. However, the complete B-cell epitope map of the CT that is responsible for protection remains to be clarified. A library of one-hundred, twenty-two 15-mer peptides covering the entire sequence of the three chains of the CT protein (CTP) was prepared by SPOT synthesis. The immunoreactivity of membrane-bound peptides with sera from mice vaccinated with an oral inactivated vaccine (Schankol™) allowed the mapping of continuous B-cell epitopes, topological studies, multi-antigen peptide (MAP) synthesis, and Enzyme-Linked Immunosorbent Assay (ELISA) development. Eighteen IgG epitopes were identified; eight in the CTA, three in the CTB, and seven in the protein P. Three V. cholera specific epitopes, Vc/TxA-3, Vc/TxB-11, and Vc/TxP-16, were synthesized as MAP4 and used to coat ELISA plates in order to screen immunized mouse sera. Sensitivities and specificities of 100% were obtained with the MAP4s of Vc/TxA-3 and Vc/TxB-11. The results revealed a set of peptides whose immunoreactivity reflects the immune response to vaccination. The array of peptide data can be applied to develop improved serological tests in order to detect cholera toxin exposure, as well as next generation vaccines to induce more specific antibodies against the cholera toxin.
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Affiliation(s)
- Salvatore G. De-Simone
- Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Diseases Populations (INCT-IDPN), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Program of Post-Graduation on Science and Biotechnology, Molecular and Cellular Biology Department, Biology Institute, Federal Fluminense University, Niterói 24020-036, RJ, Brazil
| | - Paloma Napoleão-Pêgo
- Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Diseases Populations (INCT-IDPN), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
| | - Priscilla S. Gonçalves
- Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Diseases Populations (INCT-IDPN), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Program of Post-Graduation on Science and Biotechnology, Molecular and Cellular Biology Department, Biology Institute, Federal Fluminense University, Niterói 24020-036, RJ, Brazil
| | - Guilherme C. Lechuga
- Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Diseases Populations (INCT-IDPN), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
| | - Sergian V. Cardoso
- Department of Health, Graduate Program in Translational Biomedicine (BIOTRANS), University of Grande Rio (UNIGRANRIO), Caxias 25071-202, RJ, Brazil
| | - David W. Provance
- Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Diseases Populations (INCT-IDPN), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
| | - Carlos M. Morel
- Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Diseases Populations (INCT-IDPN), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
| | - Flavio R. da Silva
- Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Diseases Populations (INCT-IDPN), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil
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White C, Bader C, Teter K. The manipulation of cell signaling and host cell biology by cholera toxin. Cell Signal 2022; 100:110489. [PMID: 36216164 PMCID: PMC10082135 DOI: 10.1016/j.cellsig.2022.110489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/01/2022] [Indexed: 11/03/2022]
Abstract
Vibrio cholerae colonizes the small intestine and releases cholera toxin into the extracellular space. The toxin binds to the apical surface of the epithelium, is internalized into the host endomembrane system, and escapes into the cytosol where it activates the stimulatory alpha subunit of the heterotrimeric G protein by ADP-ribosylation. This initiates a cAMP-dependent signaling pathway that stimulates chloride efflux into the gut, with diarrhea resulting from the accompanying osmotic movement of water into the intestinal lumen. G protein signaling is not the only host system manipulated by cholera toxin, however. Other cellular mechanisms and signaling pathways active in the intoxication process include endocytosis through lipid rafts, retrograde transport to the endoplasmic reticulum, the endoplasmic reticulum-associated degradation system for protein delivery to the cytosol, the unfolded protein response, and G protein de-activation through degradation or the function of ADP-ribosyl hydrolases. Although toxin-induced chloride efflux is thought to be an irreversible event, alterations to these processes could facilitate cellular recovery from intoxication. This review will highlight how cholera toxin exploits signaling pathways and other cell biology events to elicit a diarrheal response from the host.
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Affiliation(s)
- Christopher White
- Burnett School of Biomedical Sciences, 12722 Research Parkway, University of Central Florida, Orlando, FL 32826, USA.
| | - Carly Bader
- Burnett School of Biomedical Sciences, 12722 Research Parkway, University of Central Florida, Orlando, FL 32826, USA.
| | - Ken Teter
- Burnett School of Biomedical Sciences, 12722 Research Parkway, University of Central Florida, Orlando, FL 32826, USA.
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Effectors Targeting the Unfolded Protein Response during Intracellular Bacterial Infection. Microorganisms 2021; 9:microorganisms9040705. [PMID: 33805575 PMCID: PMC8065698 DOI: 10.3390/microorganisms9040705] [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: 02/20/2021] [Revised: 03/21/2021] [Accepted: 03/24/2021] [Indexed: 12/12/2022] Open
Abstract
The unfolded protein response (UPR) is a homeostatic response to endoplasmic reticulum (ER) stress within eukaryotic cells. The UPR initiates transcriptional and post-transcriptional programs to resolve ER stress; or, if ER stress is severe or prolonged, initiates apoptosis. ER stress is a common feature of bacterial infection although the role of the UPR in host defense is only beginning to be understood. While the UPR is important for host defense against pore-forming toxins produced by some bacteria, other bacterial effector proteins hijack the UPR through the activity of translocated effector proteins that facilitate intracellular survival and proliferation. UPR-mediated apoptosis can limit bacterial replication but also often contributes to tissue damage and disease. Here, we discuss the dual nature of the UPR during infection and the implications of UPR activation or inhibition for inflammation and immunity as illustrated by different bacterial pathogens.
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