Feedback inhibition of IgM memory cells by high antigen dose

The ability of high and low antigen doses (SRBC) to recruit IgM memory cells has been compared in several strains of mice. In intact animals priming with low doses was more efficient than priming with high doses. If, however, mice of different strains were X-irradiated two days after priming and repopulated, regardless of whether syngeneic or allogeneic splenocytes were used, they fell into two categories--those in which more memory cells were found after low antigen priming and those in which the reverse was true (Swiss mice). Two possible explanations are offered to explain these interstrain differences--antibody mediated suppression, and generation of suppressor T cells. Our data favor the latter, and we assume that suppressor T cells appear at different intervals after priming in different strains of mice, and that these cells are radioresistant.