Physiology of murine B lymphocytes. I. Life-spans of anti-mu and haptenated Ficoll (thymus-independent antigen)-reactive B cells.

We have evaluated the life-span of B lymphocytes by measuring the functional reactivity of normal B cells upon transfer into xid mice, which do not respond to anti-mu, fluoresceinated-Ficoll (FL-Ficoll) and 2,4,6-trinitrophenyl aminoethylcarbamylmethyl Ficoll (TNP-Ficoll). After 4 days of transfer only 30-40% of anti-mu-reactive cells decayed leaving behind 60-70% of B cells which appeared to decay slowly. Even 10 days after transfer approximately 40% of anti-mu-reactive B cells can be recovered from the recipients. This result demonstrates the existence of heterogeneity in the life-spans of anti-mu-reactive B lymphocytes and that a major population (60-70%) of B cells persists beyond 4 days. Interestingly, the short-lived B cell subpopulation was not detected when the decay of the antigen-specific B cells was studied. Thus, TNP-Ficoll and FL-Ficoll-reactive B cells were found to be long lived and such B cells did not decline at all, even 5 months after transfer into xid mice.