Activation of antigen-enriched B cells. I. Purification and response to thymus-independent antigens

The development of a procedure for the selection of a large number of functional antigen-binding B cells is described. Forty to 70% of the cells in the enriched population bind antigen, and the antigen-binding can be inhibited by pretreatment with either the free hapten (TNP-Lys) or anti-immunoglobulin. The enriched cells express both sIgM and sIgD and respond to mitogenic stimuli by proliferating and developing into antibody-forming cells. In contrast to normal spleen cells, however, the enriched cells also proliferate in response to sub-mitogenic levels of TNP-Brucella abortus and TNP-LPS.