Prediction of CTL epitopesof Tat exon 1 region in HIV-1 CRF07_BC strains in China

Abstract

：Objective To predict theCTL epitopes of Tat exon 1 region in HIV-1 CRF07_BC strains, which were prevailing inChina. Methods Total of 236 plasma samples were from the 3rd National HIV MolecularEpidemic Survey (NMES3). All the subjects were infected with HIV-1 CRF07_BC viruses. Thetat exon 1 region was amplified by reverse transcription reaction and nested polymerasechain reaction (nested-PCR), then the PCR products were sequenced. The distribution of CTLepitopes of this region were predicted by on-line software BIMAS HLA Peptide BindingPredictions and statistics software. Results To-tal of 236 CRF07_BC strains were from 16provinces, mainly in intravenous drug asers(58.9%)and then sex(25.0%). It was showed thatthere were 12 CTL epitopes of 236 Tat exon 1 region of CRF07_BC strains mainly located inproline-rich region, cysteine-rich region and core-region. Those epitopes were banded by 5HLA presenting molecules in genotype(A * 2501 ,A * 2902, B * 15,B * 5301 and Cw * 1203)and 6 HLA presenting molecules in serotype (B53, B58 ,B57 ,A3 ,A68 and Cw12). Thefrequency of single amino acid substitution was more than 50% in 7 CTL epitopes.Conclusion The CTL epitopes in Tat exon 1 of CRF07 _BC strains were located in differentfunctional regions, and there were some amino acid variations in them.