Selective participation of immunoglobulin V region and major histocompatibility complex products in antigen binding by T cells

Antigen‐binding inhibition studies using microscopic autoradiography were performed on T or B cell‐enriched lymphocyte populations. Antibodies specific for the “framework” of immunoglobulin heavy or light chain variable domains (V_H or V_L), or anti‐H‐2 and anti‐Ia antisera were used. T cell subclasses were separated with anti‐Lyt antisera and complement. It was found that antigen‐binding T cells of different subclasses can be inhibited selectively with only one of the two anti‐V region antibodies. Antigen binding to Lyt‐1⁺ cells was inhibited by anti‐V_H, while Lyt‐2⁺,3⁺ cells were inhibited by anti‐V_L specifically. Anti‐Ia antisera inhibited unprimed Lyt‐1⁺ antigen‐binding cells, whereas anti‐H‐2K or anti‐H‐2D antisera inhibited unprimed Lyt‐2⁺,3⁺ antigen‐binding cells, and both classes of immune T antigen‐binding cells.