ANTIGEN-SPECIFIC B-CELLS IN TISSUES AFTER ORAL TYPHOID VACCINATION

Six human subjects who were to receive elective bowel surgery for a va riety of diseases were vaccinated with the oral typhoid vaccine, Ty21a . Intestinal tissue (ileum in two, large intestine in four) removed 7- 26 days after the first dose of vaccine was examined for the presence and distribution of antigen-specific B cells. This was compared with i ntestinal tissue derived from two unvaccinated controls. A number of B cell differentiation antigens were also assessed on these cells by im munofluorescence using dual-labelling. Antigen-specific cells were fou nd randomly distributed in the lamina propria of all the vaccinated su bjects in low frequency (6+/-0.5 to 37+/-31 [mean+/-s.e.m.] antigen sp ecific cells/10 mm(2) of tissue). The lymphocyte differentiation antig ens CD45RA, CD45RO, L-selectin, CD-11a CD-38, CD-44 and VLA-4 were all found on antigen-specific cells, but no particular pattern was recogn izable in this small series of six subjects with different disease pro cesses affecting the intestine.