[Effects of anti-MB and anti-DR monoclonal antibodies on in vitro immune responses]

The present study has addressed the effects of anti-DR and anti-MB monoclonal antibodies on various in vitro immune responses. The anti-DR monoclonal antibody HU-4 was found to inhibit T cell proliferative responses to PPD, autologous non-T cells, autologous EB-virus-transformed B cells, and alloantigens. Furthermore, HU-4 strongly inhibited generation of killer T cells specific for autologous EB-virus-transformed B cells and alloantigens. In contrast, the anti-MB monoclonal antibody HU-18 did not affect any of these in vitro responses to a significant degree, and its effect was largely comparable to that of a class I specific monoclonal antibody. Thus, these results indicate that DR rather than MB antigens play a major role in the in vitro systems studied in this investigation. Possible implications of these observations were discussed by comparing our results with those known in mice.