EPITOPE SPECIFICITY, ANTIBODY-DEPENDENT CELLULAR CYTOTOXICITY, AND NEUTRALIZING ACTIVITY OF ANTIBODIES TO HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 IN AUTOIMMUNE MRL LPR MICE/

The specificity and functional activity of antibodies to human immunod eficiency virus (HIV) in the sera of MRL/lpr mice were analyzed by pep tide-ELISA, antibody-dependent cellular cytotoxicity, and virus neutra lization. The specificity of the antibodies in the sera of autoimmune MRL/lpr mice was similar to that of HIV-infected persons; the mouse se ra specifically recognized the V3 loop of gp120 and immunodominant reg ions of gp41 and p24. Moreover, such binding was inhibited both by hum an HIV-positive sera and by soluble peptides in competition experiment s. MRL/lpr sera displayed anti-HIV antibody-dependent cellular cytotox icity using human peripheral blood lymphocytes as effector cells and H IV-infected H9 cells. Furthermore, the fact that MRL/lpr sera neutrali zed in vitro infectious HIV (both strains IIIB and MN) suggests these antibodies recognize viral epitopes on the membrane of infected T cell s.