人巨细胞病毒临床株US3基因HLA-A*0201限制性CTL表位预测

Objective To analyze the genetic variations of cytomegalovirus US3 gene in clinical strains, and to predict the HLA-A*0201 restricted CTL epitopes of the protein in late jaundice infants. Methods Nest PCR was performed to amplify the entire HCMV-US3 gene region of clinical strains collected from 20 HCMV infected infants. The PCR products were sequenced and the SYFPEITHI and NetCTL were used to predict the potential T cell CTL epitopes of US3 protein. Results By comparison with Towne sequence, the length of US3 ORF in all 20 clinical isolates was similar to that of the reference isolates, 561 bp in size. Most amino acid sequence of US3 was highly conserved although several strains had variation. Those mutations focused on the N end of US3, but most of them were sense mutation. The HLA-A*0201 restricted CTL epitopes of US3 protein generated by combined application of SYFPEITHI and NetCTL: FTEKHFVSV, RMDYSSQTI, RMDYSSHTI, SIRDDNWGL and SMRDDNWGL. There were some differences in CTL epitopes of US3 encoded protein in various strains. Conclusions Five epitopes derived from US3 gene were confirmed as HLAA*0201 restricted CTL epitopes. The present study has offered experimental support for further investigation of pathogenic mechanism of HCMV.