CD8 CTL responses in vaccines: emerging patterns of HLA restriction and epitope recognition

We evaluated MHC-class I-restricted CTL responses induced by HIV-1 clade B- based vaccines in nine HIV-1 seronegative vaccine recipients with regard to their patterns of HLA restriction and epitope recognition. We found that s even of nine volunteers developed detectable CTL reactivities against novel epitopes within the HIV-1 Env and Gag proteins. Although four of nine subj ects were HLA-A*0201, none of the cellular responses was restricted in the context of this allele. The type of responses observed in this sampling of vaccines appeared similar to those reported during primary infection and am ong long term non-progressors, with three out of nine subjects recognizing HLA-B27 or HLA-B17(57)-restricted epitopes. Although the majority of CTL re sponses were directed against novel epitopes, these effectors were still ab le to mediate cross-clade reactivities. (C) 2001 Elsevier Science B.V. All rights reserved.