Anti-viral antibodies in HIV (HTLV-III) infection possess auto-antibody activity against a CH1 domain determinant in human IgG: possible immunological consequences

Abstract Two regions of the envelope glycoprotein gp120 of the human immunodeficiency virus were shown to have a significant degree of homology to human immunoglobulin-γ heavy-chain constant domains. We have now synthesized three short linear peptides, the first representing a sequence within the CH1 domain, the second an analogue of it, and the third representative of a region within the viral gp120. Polyclonal antibodies against these peptides were raised in rabbits and used to demonstrate that they all reacted well with human native IgG. Vice-versa, we observed the reaction of these antisera to the virus in an ELISA system. The proportion of sera reacting with the human γ-chain peptide was significantly higher in HIV-positive individuals than in HIV-negative individuals, suggesting production of anti-viral antibodies in AIDS patients with auto-antibody activity against a CH1 domain determinant in human IgG.