In vitro tolerance induction of neonatal murine B cells as a probe for the study of B-cell diversification.

Abstract

The susceptibility to in vitro tolerance induction was implicated as a characteristic of B [bone marrow-derived] cells early in their development, since DNP[dinitrophenol]-reactive B cells are tolerizable only during the 1st days after birth, and 25% of adult bone marrow cells are tolerizable. In the present study a modification of the in vitro splenic focus technique was utilized to determine if PC[phosphorylcholine]-specific B cells, by virtue of their late expression (approximately 1 wk post-parturition), also display susceptibility to tolerance induction. At 7-10 days after birth, when over 90% of the DNP-specific splenic B cells are resistant to tolerance induction, the majority of PC-specific B cells are tolerizable. These results re-emphasize tolerance susceptibility as a characteristic of developing clones, confirm the late acquisition of PC-specific B cells, and show that the acquisition of the specificity repertoire is probably a highly ordered, specifically predetermined process which is independent of antigen-driven events.