Delineation of tolerance-sensitive and tolerance-insensitive B cells in normal and immune defective mice.

B cells responsive to TNP on various thymus-independent carriers acquire immunocompetence at different times during ontogeny and elicit varying levels of responsiveness in immune-defective CBA/N mice. Such B cells have now been found to display differential tolerance susceptibilities in a hapten-specific in vitro tolerance assay. B lymphocytes from normal neonatal or immune-defective adult CBA/N mice responsive to TNP-lipopolysaccharide were shown to be hypersusceptible to tolerogenesis whereas B cell responses to a second TI antigen, TNP-Brucella abortus, were not rendered tolerant until high concentrations of tolerogen had been presented. Therefore, tolerance hypsersusceptibility is characteristic of a fraction of neonatal and immune-defective adult CBA/N antigen-reactive B lymphocytes.