The role of monocyte lymphocyte function-associated antigen 1 (LFA-1) in accessory cell function.

Monoclonal antibodies directed against the common beta subunit shared by lymphocyte function-associated antigen-1 (LFA-1), CR3 and p150,95 or the alpha subunit of LFA-1, inhibited the T lymphocyte proliferative response to tetanus toxoid, pokeweed mitogen-1 and OKT3 but had little or no effect on the response to the leukoagglutinating lectins pokeweed mitogen-2 and phytohemagglutinin. The LFA-1 molecule was shown to participate in the adhesive interaction between monocytes and T lymphocytes that was required for the initiation of an immune response. Both monocyte and T lymphocyte LFA-1 were found to contribute to this interaction. These results further define the part played by the LFA-1 molecule in the activation of T lymphocytes.