DETECTION OF ANTIBODIES TO HIV-1 GP41-DERIVED AND HLA CLASS-II ANTIGEN-DERIVED PEPTIDES IN SLE PATIENTS

A role for viruses in the pathogenesis of human autoimmune diseases has long been suspected but has not yet been proven. Highly conserved homologous regions has been reported in the carboxy terminus of human immunodeficiency virus (HIV)-1 gp41 (amino acids 838-844) and the amino-terminal of the beta chain of all human HLA class II antigens (amino acids 19-25). This molecular mimicry between HIV-1 and HLA class II antigens may lead to the generation of autoantibodies and may contribute to the development of autoimmune phenomena in HIV infected patients. We detected antibodies for these homologous peptides from HLA class II and HIV-1 gp41 in systemic lupus erythematosus (SLE) patients without HIV-I infection. Thirty-seven percent of the SLE patients had IgM antibodies reacting with both HLA class II- and HIV-1 gp41-derived peptides. These results suggest the possibility that a retrovirus may be one of the causative agents of SLE.