Nonrandom distribution of vibriolytic foci in the spleen of mice lacking "background" antibody.

Abstract

Discrete foci of specific bacteriolytic activity are detectable with frozen sections from the spleen of mice immunized with V. cholerae. Development of foci can be suppressed substantially by incorporation of antiglobulin serum or soluble vibrio antigen into the assay agar. Passive injection of specific antibody into nonimmunized mice does not lead to foci formation. Furthermore, there are no background foci detectable in normal, nonimmunized mice. The number of foci increases with time after immunization and this increase correlates with the number of single antibody plaque-forming cells. The foci of antibody-forming cells are distributed in the spleen nonrandomly in 2 to 6 distinctive areas. The number of foci in each area increases with time after immunization. This suggests that antigen reactive precursor cells may be activated only in a few limited areas of the spleen.