DISCRIMINATION BETWEEN HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-I AND TYPE-II (HTLV-I AND HTLV-II) INFECTIONS BY USING SYNTHETIC PEPTIDES REPRESENTING AN IMMUNODOMINANT REGION OF THE CORE PROTEIN (P19) OF HTLV-I AND HTLV-II

We describe enzyme immunoassays that use synthetic oligopeptides to di scriminate serologically between human T-cell lymphotropic virus type I and II (HTLV-I and HTLV-II) infections. The peptides represented 20- amino acid segments between residues III and 130 (MA1) and residues 11 6 and 135 (MA2) of the p19gag proteins of HTLV-I and HTLV-II, respecti vely. The assays were sensitive since 69 of 74 HTLV-positive sera were reactive to at least one of the two matrix (MA) peptides (sensitivity , 93.2%). By using the ratio of the optical density of MA1 to the opti cal density of MA2, which represents for every serum sample the ratio between the absorbance value obtained in the MA1 assay and the absorba nce value obtained in the MA2 assay, 59 of the 69 reactive serum sampl es were clearly and easily typed as positive for either antibody to HT LV-I or antibody to HTLV-II. Eight of the 10 remaining reactive serum samples were analyzed further by an inhibition procedure, and their ty pe specificities were then clearly identifiable. Therefore, the result s indicate that all MA-reactive sera were serologically distinguished by our peptide assays.