HUMAN CLASS-I SUPERTYPES AND CTL REPERTOIRES EXTEND TO CHIMPANZEES

Using an in vitro peptide stimulation strategy, two chimpanzees that w ere acutely infected by the hepatitis B virus (HBV) produced periphera l blood CTL responses to several HBV-encoded epitopes that are known t o be recognized by class I-restricted CTL in acutely infected humans. One animal responded to three HBV peptides that, in humans, are restri cted by HLA-A2; the other animal responded to three peptides that are restricted by HLA-B35 and HLA-BSI, members of the HLA-B7 supertype in man. The peptides recognized by each chimp corresponded with the abili ty of its class I molecules to bind peptides containing the HLA-A2 and HLA-B7 supermotifs. Similar, apparently class I-restricted CTL respon ses to some of these peptides were also detected in occasional HBV-uni nfected chimps. These results demonstrate that the CTL repertoire over laps in humans and chimps and that the HLA-A2 and HLA-B7 supertypes ex tend to the chimpanzee. Based on these results, the immunogenicity and efficacy of vaccines designed to induce CTL responses to human HLA-re stricted viral epitopes may be testable in chimpanzees.