High frequency of Mlsa-reactivity among Ab-restricted, H-Y-specific T cell clones.

A high frequency (80%) of Ab-restricted, H-Y-specific T cell clones, but not of Ab-restricted LDH-B-specific T cell clones, was found to be Mlsa-reactive. This reactivity could be inhibited by class II (A and E)-specific antibodies, and required an E-positive stimulator cell. The proliferation was also blocked by T cell receptor-specific and by CD4-specific antibodies. Possible interpretations of these findings are discussed.