Recognition of variant HIV-1 epitopes from diverse viral subtypes by vaccine-induced CTL.
Recognition by CD8(+) T lymphocytes (CTL) of epitopes that are derived from conserved gene products, such as Gag and Pol, is well documented and conceptually supports the development of epitope-based vaccines for use against diverse HIV-1 subtypes. However, many CTL epitopes from highly conserved regions within the HIV-1 genome are highly variable, when assessed by comparison of amino acid sequences. The TCR is somewhat promiscuous with respect to peptide binding, and, as such, CTL can often recognize related epitopes. In these studies, we evaluated CTL recognition of five sets of variant HIV-1 epitopes restricted to HLA-A*0201 and HLA-A*1101 using HLA transgenic mice. We found that numerous different amino acid substitutions can be introduced into epitopes without abrogating their recognition by CTL. Based on our findings, we constructed an algorithm to predict those CTL epitopes capable of inducing responses in the HLA transgenic mice to the greatest numbers of variant epitopes. Similarity of CTL specificity for variant epitopes was demonstrated for humans using PBMC from HIV-1-infected individuals and CTL lines produced in vitro using PBMC from HIV-1-uninfected donors. We believe the ability to predict CTL epitope immunogenicity and recognition patterns of variant epitopes can be useful for designing vaccines against multiple subtypes and circulating recombinant forms of HIV-1.
McKinney
Denise M
DM
Epimmune, San Diego, CA 92121, USA.
Skvoretz
Rhonda
R
Livingston
Brian D
BD
Wilson
Cara C
CC
Anders
Michelle
M
Chesnut
Robert W
RW
Sette
Alessandro
A
Essex
Max
M
Novitsky
Vladimir
V
Newman
Mark J
MJ
D016915:AIDS Vaccines / Q000276:immunology*; D000465:Algorithms; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D000940:Antigenic Variation / Q000235:genetics / Q000276:immunology*; D000939:Epitopes / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D015686:Gene Products, env / Q000737:chemistry / Q000276:immunology; D015683:Gene Products, gag / Q000737:chemistry / Q000276:immunology; D015684:Gene Products, pol / Q000737:chemistry / Q000276:immunology; D005805:Genes, MHC Class I; D015488:HIV Antigens / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000145:classification / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000235:genetics / Q000276:immunology; D015791:HLA-A3 Antigen / Q000235:genetics / Q000276:immunology; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D016415:Sequence Alignment; D037182:T-Cell Antigen Receptor Specificity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D016915:AIDS Vaccines; D000939:Epitopes; D015686:Gene Products, env; D015683:Gene Products, gag; D015684:Gene Products, pol; D015488:HIV Antigens; D015789:HLA-A2 Antigen; D015791:HLA-A3 Antigen; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell