CROSS-REACTIVITY AND AMINO-ACID HOMOLOGY OF IMMUNODOMINANT PEPTIDE-FRAGMENTS OF STRUCTURAL PROTEINS OF HUMAN RETROVIRUSES HTLV-I, HTLV-II, HIV-1, AND HIV-2

Cross-reactivity with heterotypic anti-retrovirus antibodies was studied by immunoenzyme analysis of twelve synthetic peptide antigens corresponding to nine immunodominant regions of structural proteins of human retroviruses HTLV-I, HIV-1, and HIV-2. A computer search for homologies between cross reacting peptides and retrovirus heterotypic proteins was made, as well as an analysis of the correspondence between the homologous regions revealed and the immunodominant fragments. It has been found that the 10-130 p19 gag HTLV-I, 376-392 gp21 env HTV-I, 381-400 gp21 env HTLV-I, 306-328 gp120 env HIV-1 and 581-603 gp36 env HIV-2 proteins are not only type-specifically reactive, but also cross-react with 3 to 54 percent of antisera containing antibodies against heterotypic retroviruses. On the other hand, the 120-130 p19 gag HTLV-I, 176-201 gp46 env HIV-1 and 602-624 gp46 env HIV-2 fail to show the cross-reactivity and can be used for type-specific and differential serodiagnostics of human retrovirus infection.