Antigen-specific T-helper cells stimulate H-2-compatible and H-2-incompatible B-cell blasts polyclonally.

Abstract

Lipopolysaccharide (LPS)-activated B [bone marrow-derived] cell blasts from C57BL/6J nu/nu spleen cells develop into Ig[immunoglobulin]M-secreting clones after stimulation by antigen-specific T [thymus-derived] helper cells of C57BL/6J origin. Although induction of help is antigen-dependent, help itself acts polyclonally. One of 1-3 B cell blasts is restimulated in a homologous fashion by LPS or in a heterologous fashion by sheep erythrocyte (SRC)- or horse erythrocyte (HRC)-activated T helper cells. The repertoire of activated B cell blasts reflects the polyclonal nature of activation; .apprx. 1 in 1000-3000 restimulated B cell blasts is specific for SRC, 1 in 300-1000 is specific for HRC and 1 in 100-300 specific for trinitrophenylated SRC (TNP30-SRC). B cell blasts that are H-2 compatible or H-2 incompatible with the antigen-activated T cell help are stimulated polyclonally in similar high frequencies. Neither antigen nor H-2 compatibility are required to stimulate a B cell blast into the next cell cycle.