ANTIGEN-BINDING LYMPHOCYTES IN GUINEA-PIGS .1. B CELL EXPANSION TO MONOVALENT ANTIGEN L-TYROSINE-PARA-AZOPHENYL TRIMETHYLAMMONIUM (TYR(TMA)) IN ABSENCE OF ANTIBODY-PRODUCTION

Abstract

The monofunctional antigen tyr(TMA), and the polyfunctional antigen, TMA-human .gamma.-globulin (TMA-HGG), were used to investigate the antigen structural requirements necessary for clonal proliferation of B [bone marrow-derived] cells. This clonal expansion was characterized with respect to receptor immunoglobulin (Ig) class and affinity maturation. Antigen-binding analysis revealed that inoculation of tyr(TMA), although only of MW 344, triggers clonal expansion of B lymphocytes 9-fold in the absence of any apparent antibody production. There does not appear to be any maturation with respect to antibody class since > 90% of the tyr(TMA)-specific B cells bear the .mu. receptor in the nonimmune and immune state. The average avidity of the B cells for this antigen increases with time after immunization. Immunization with TMA-HGG results in an 18-fold increase in B lymphocytes with significant amounts of anti-TMA antibody production. With time after immunization, maturation of average avidity and class of Ig receptor (.mu. .fwdarw. .gamma. shift) occur. The functionally T [thymus-derived] cell-specific antigen tyr(TMA) can apparently trigger clonal B cell expansion and affinity maturation at the receptor level in the absence of detectable antibody production.