Cholera Toxin-Specific Memory B Cell Responses Are Included in Patients with Dehydrating Diarrhea Caused by Vibrio cholerae O1.
Jayasekera, Chana R. 1,a; Harris, Jason B. 3,4,a; Bhuiyan, Saruar 1; Chowdhury, Fahima 2; Khan, Ashraful I. 2; Faruque, Abu S. G. 2; LaRocque, Regina C. 3,5; Ryan, Edward T. 3,5,7; Ahmed, Rafi 8; Qadri, Firdausi 1; Calderwood, Stephen B. 3,5,6
[Article]
Journal of Infectious Diseases.
198(7):1055-1061, October 1, 2008.
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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 mononuclear 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.
(C) Copyright Oxford University Press 2008.
