Cholera toxin-specific memory B cell responses are induced in patients with dehydrating diarrhea caused by Vibrio cholerae O1.
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.
Jayasekera
Channa R
CR
International Centre for Diarrhoeal Disease Research, Bangladesh.
Harris
Jason B
JB
Bhuiyan
Saruar
S
Chowdhury
Fahima
F
Khan
Ashraful I
AI
Faruque
Abu S G
AS
Larocque
Regina C
RC
Ryan
Edward T
ET
Ahmed
Rafi
R
Qadri
Firdausi
F
Calderwood
Stephen B
SB
D000907:Antibodies, Bacterial / Q000097:blood; D001402:B-Lymphocytes / Q000276:immunology*; D002771:Cholera / Q000276:immunology*; D002772:Cholera Toxin / Q000276:immunology*; D003967:Diarrhea / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D041241:Vibrio cholerae O1
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D002772:Cholera Toxin