Cholera Toxin-Specific Memory B Cell Responses Are Induced in Patients with Dehydrating Diarrhea Caused by Vibrio cholerae O1

• Published in: The Journal of infectious diseases 2008-10, Vol.198 (7), p.1055-1061
• Main Authors: Jayasekera, Channa R., Harris, Jason B., Bhuiyan, Saruar, Chowdhury, Fahima, Khan, Ashraful I., Faruque, Abu S. G., LaRocque, Regina C., Ryan, Edward T., Ahmed, Rafi, Qadri, Firdausi, Calderwood, Stephen B.
• Format: Article
• Language: English
• Subjects: Antibodies; Antibodies, Bacterial - blood; Antigens; B lymphocytes; B-Lymphocytes - immunology; Bacteria; Bacterial diseases; Bacteriology; Biological and medical sciences; Cholera; Cholera - immunology; Cholera Toxin - immunology; Cultured cells; Diarrhea - immunology; Enzyme linked immunospot assay; Fundamental and applied biological sciences. Psychology; Human bacterial diseases; Humans; Immunoglobulin A - blood; Immunoglobulin G - blood; Immunologic Memory; Immunology; Infections; Infectious diseases; Medical sciences; Memory; Microbiology; Miscellaneous; Tropical bacterial diseases; Vibrio cholerae; Vibrio cholerae O1
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1086/591500

Background. Infection with Vibrio cholerae induces durable immunity against subsequent disease, a process hypothesized to reflect anamnestic immune responses at the intestinal mucosa. The presence of antigen-specific memory B cells may therefore be a more direct measure of protection than serum antibody responses. Methods. We measured immunoglobulin (Ig) G memory B cells specific to cholera toxin B subunit (CTB) in 14 patients up to 90 days after V. cholerae O1 infection, by polyclonal stimulation of peripheral blood mononudear cells followed by standard enzyme-linked immunospot assay. Results. All patients generated CTB-specific IgG memory B cell responses by day 30 (mean, 0.10% of total circulating IgG memory B cells; range, 0.037%–0.28%), which persisted to day 90 (mean, 0.07%; range, 0.003%–0.27%). In contrast, circulating CTB-specific IgG antibody-secreting cells and serum vibriocidal and anti-CTB antibody responses peaked on day 7 and declined to undetectable or significantly lower levels by day 90. Conclusions. CTB-specific IgG memory B cell responses are detectable in the circulation at least 3 months after V. cholerae O1 infection and remain measurable even after serum antibody titers have declined to undetectable or considerably lower levels. This suggests that antigen-specific memory B cells may be an important long-term marker of the immune response to cholera.