HIVGP120 ACTIVATES AUTOREACTIVE CD4-SPECIFIC T-CELL RESPONSES BY UNVEILING OF HIDDEN CD4 PEPTIDES DURING PROCESSING

T cells are made tolerant only to those self-peptides that are present ed in sufficient amounts by antigen-presenting cells. They ignore cryp tic self-determinants, such as either those not generated by processin g machinery or generated in insufficient amounts. It is anticipated th at mechanisms that either change antigen processing or increase the yi eld of previously ''invisible'' peptides may be capable of inducing T cell priming and, if they are self-maintained, may sustain autoimmune diseases. Herein, we demonstrate for the first time a mechanism by whi ch the gp120 human immunodeficiency virus-I, by downregulating plasma membrane CD4 and increasing its processing, unveils hidden CD4 epitope s, inducing an autoimmune-specific T cell response.