Chimeric synthetic peptides containing two immunodominant epitopes from the envelope gp46 and the transmembrane gp21 glycoproteins of HTLV-I virus

Two chimeric synthetic peptides incorporating immunodominant sequences from HTLV-I virus were synthesized. Monomeric peptides P7 and PS represent sequ ences from transmembrane protein (gp21) and envelope protein (gp46) of the virus. The peptide P7 is a gp21 (374-400) sequence and the peptide PS is a gp46 (190-207) sequence. Those peptides were arranged in a way that permits one to obtain different combinations of chimeric peptides (P7-GG-P8 and P8 -GG-P7), separated by two glycine residues as spacer arms. The antigenic ac tivity of these peptides were evaluated by UltramicroEnzyme-linked immunoso rbent assay (UMELISA) by using panels of anti-HTLV-1-positive sera (n = 22) , anti-HTLV-I/II-positive sera (n = 2), HTLV-positive (untypeable) serum sa mples (n = 2), and anti-HTLV-II-positive sera (n = 11), while specificity w as evaluated with anti-HIV-positive samples (n = 19) and samples from healt hy blood donors (n = 30). The efficacy of the chimeric peptides in solid-ph ase immunoassays was compared with the monomeric peptides and monomeric pep tides together. The chimeric peptide P7-GG-P8 proved to be the most reactiv e with anti-HTLV-1-positive sera. These results may be related to a higher peptide adsorption capacity to the solid surface and for epitope accessibil ity to the antibodies. This chimeric peptide would be very useful for HTLV- 1 diagnostics. (C) 2001 Academic Press.