Functional half‐life of virgin and primed B lymphocytes

Abstract

The functional half-life, a measure of the persistence of lymphocytes in an antigen-free environment, has been estimated and found to be about 7 days for virgin 2,4,6-trinitrophenyl (TNP)-reactive mouse B cells, and 2–3 times longer for TNP-primed B cells. Using allotype-congenic mice, lymph node cells were transferred from virgin or primed CBA/Ig^b donors to normal CBA/Ig^a recipients, and the proportion of donor B cells estimated at intervals. This was done by making a further transfer to irradiated recipients and challenging with a TNP conjugate. The donor contribution declined with time in approximately exponential fashion to give the functional half-life. The experiment with primed cells necessitated mixing them with virgin cells, and thus allowed the possibility of interactions. However, control experiments showed that, at least in the final transfer, the primed cell response was not decreased by the presence of excess virgin cells - although primed cells suppressed virgin cells. In other experiments where the intermediate hosts were treated with vinblastine, it was shown that primed B cells have a slower turnover rate than virgin B cells. The relevance of these results to the problem of B cell tolerance is discussed.