Phenotypic and functional properties of B lymphocytes from aged mice.

Phenotypic and functional properties of B lymphocytes from individual young and old mice of different inbred strains were studied. B lymphocyte subpopulations defined by the ratios of the densities of cell surface IgM and IgD were found to be altered with age. However, such alterations in B cell subsets were found only in 30-40% of the old mice. B cell mitogenic responses to anti-mu and anti-Lyb2 antibodies were decreased in a majority of DBA/2 mice. Proliferative responses to LPS and anti-mu were reduced only in a minority of CBA/Ca mice but there was a very good correlation in the responsiveness of the old mice to LPS and anti-mu. The anomalous properties of the individual old mice of these inbred strains may be due to a heterogeneity in the effects of aging or due to environmental influences.