Immune memory to a nonmitogenic, thymic independent antigen in mice: variation among inbred strains and possible...

Immune memory to DNP-Ficoll, a nonmitogenic, thymic-independent (TI-2) antigen, was demonstrated in several inbred strains of mice. Direct and indirect splenic plaque-forming cell responses were measured in mice given a secondary challenge with DNP-Ficoll and in appropriate control mice. Strong IgM memory, but no IgG memory, was observed in SJL/J, AKR/J, and C58/J mice. C57L/J mice gave both a strong IgM memory response and a relatively strong IgG memory response to DNP-Ficoll. C57BL/6N, C57BR/cdJ, and A/HeJ mice were unable to mount significant IgM or IgG memory responses to this antigen under an identical immunization schedule. These results are indicative of marked genetic variation in mice in the capacity for B memory cell expression. They also identify a provocative but unexplained association between positive IgM memory responses to DNP-Ficoll in SJL/J, AKR/J, and C58/J mice and a propensity to develop lymphoreticular neoplasia. This association is observed when there is no clear evidence for IgG memory.