Anti-immunoglobulin stimulation of murine lymphocytes. I. Age dependency of the proliferative response.

The in vitro proliferative response of normal mouse spleen cells to anti-immunoglobulin (Anti-Ig) reagents was found to be an age-associated phenomenon. The response usually appears in mice when they reach 5 to 7 months of age and is rarely seen in younger animals. Anti-Ig induced proliferation was observed by using two different antisera--one polyvalent, prepared against mouse antibody-antigen complexes and one prepared against mouse IgM myeloma. Both antisera were shown to be specific for B cells by cytotoxicity and immunofluorescent staining. Glassbead separation of spleen cells showed that the anti-Ig-induced proliferation was a B cell response.