EVIDENCE OF WIDESPREAD BINDING OF HLA CLASS-I MOLECULES TO PEPTIDES

We have tested the binding of HLA class I proteins to peptides using a solid-phase binding assay. We tested 102 peptides, mostly derived from the HIV gag and HIVpol sequences. Most peptides did not bind to any class I protein tested. The pattern ofbinding among the three class I proteins tested, HLAA2, -B27, and -B8, was appropriately 85% concordant. Further, all five ofthe known HIV-1 gag T cell epitopes detected by human CTL bound at least one class I protein. Binding ofclass I to the peptides could be detected either by directly iodinated class I proteins, or indirectly using monoclonal antibodies specific for class I. The binding to the plates could be blocked with MA2.1, which binds in the al region of A2, but not by W6/32, which binds elsewhere. The data presented here show that binding of class I to peptides is specific, but that many peptides bind to more than a single class I protein. © 1990, Rockefeller University Press., All rights reserved.