Immune responses in vitro. V. Suppression of M, G, and A plaque-forming cell responses in cultures of primed mouse spleen cells by class-specific antibody to mouse immunoglobulins.

Suppression of Ig class-specific PFC responses by class-specific antibody to mouse immunoglobulin was studied in cultures of spleen cells from immunized mice. In contrast to cultures from normal mice where anti-micro suppressed responses in all Ig classes, anti-micro had progressively less suppressive effect on gamma(1) and gamma(2) responses in cultures from immunized mice with time after immunization. This was most pronounced at 10 days after immunization when anti-micro suppressed gammaM and gammaA responses, but had no or slight effect on gamma(1) or gamma(2) responses which were still suppressed with anti-gamma(1) and anti-gamma(2). These changes in precursor cell susceptibility to anti-micro were antigen specific.