ADVANTAGE OF DIMERIC PEPTIDE ANTIGENS IN SERODIAGNOSIS OF HIV-1 INFECTION

The reactivity of antibodies with dimeric and monomeric peptide antige ns was compared by ELISA. A panel of highly purified synthetic peptide s of HIV-1 representing defined regions, 598-609 and 524-533 (fusion d omain) of gp41 and 306-320 of gp120, were used as antigens in the ELIS A. These peptides were selected and synthesized taking into account th e level of sequence conservation of various strains and hydrophilicity . The analysis included sera from 52 HIV-1 infected individuals and 53 HIV-1 negative controls. Both peptides from gp41 were found to be par ticularly immunoreactive with sera from HIV-1 infected individuals. Th e frequency of reactivity to the selected peptide from gp120 (V-3 loop ) in infected individuals was 82%. An interesting observation was that the dimeric peptide antigens had a detection rate more than 4-fold hi gher than the monomeric antigens. We found that lower levels of antibo dies could be detected with dimeric antigens. The peptides reacted wit h few sera other than HIV-1 positive sera. These results implicate the potential dimeric peptide antigens to be utilized in the serodiagnosi s of HIV-1 infection.