Association between CTL epitope variations of Nef protein and viral loads in HIV-1 B’ infectors
Author(s): HU Yuanyuan, CHEN Yanli, ZHANG Dai, ZOU Sen, HOU Jiali, REN Li, HAO Yanling, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory of Infectious Disease Control and Prevention
Pages: 1070-1073
Year: 2016 Issue: 11
Journal: China Tropical Medicine
Keyword: HIV-1; Nef protein; CTL epitopes; viral load;
Abstract: Objective We explored the potential relationship between cytotoxic T lymphocyte(CTL) epitope variations ofNef protein and viral loads in HIV-1 B’ infectors. Methods Viral RNAs were isolated from 137 plasm samples of HIV-1 B’infectors and c DNAs were synthesized by reverse transcription. Nef genes were amplified by RT- and nested-PCR, and PCRproducts were sequenced directly,and then translated into protein sequence. Nef protein sequences were compared with theexperiment-validated CTL epitopes in HIV immunology database. The CTL epitope variation of Nef protein and its influence onthe viral load of the infected person were analyzed. Results Compared with the CTL epitopes in the HIV immunologydatabase, there were a few of variation in most CTL epitopes of the Nef protein in 137 HIV-1 B’ infected individuals. Therewere only 5 epitopes with a mutation frequency of more than 10%. The variation of flank region was more frequently observedthan the anchor site, there was a positive correlation between the viral load and the frequency of variation in total epitopes,anchor site and flank region. However, we didn’t observed a positive correlation between the viral load and the frequency ofvariation in non-anchor site. Conclusion There are relatively conservative in most CTL epitopes of Nef protein,the variationof flank region was more frequently than the anchor site in CTL epitope, the frequency of first amino acid mutation to upstreamand downstream of flank region is higher,the variation of amino acid sequence in flank region may be the main way of escapemutation of Nef protein.The relationship of the variation in CTL epitopes and the damage of viral fitness needs further study。
Pages: 1070-1073
Year: 2016 Issue: 11
Journal: China Tropical Medicine
Keyword: HIV-1; Nef protein; CTL epitopes; viral load;
Abstract: Objective We explored the potential relationship between cytotoxic T lymphocyte(CTL) epitope variations ofNef protein and viral loads in HIV-1 B’ infectors. Methods Viral RNAs were isolated from 137 plasm samples of HIV-1 B’infectors and c DNAs were synthesized by reverse transcription. Nef genes were amplified by RT- and nested-PCR, and PCRproducts were sequenced directly,and then translated into protein sequence. Nef protein sequences were compared with theexperiment-validated CTL epitopes in HIV immunology database. The CTL epitope variation of Nef protein and its influence onthe viral load of the infected person were analyzed. Results Compared with the CTL epitopes in the HIV immunologydatabase, there were a few of variation in most CTL epitopes of the Nef protein in 137 HIV-1 B’ infected individuals. Therewere only 5 epitopes with a mutation frequency of more than 10%. The variation of flank region was more frequently observedthan the anchor site, there was a positive correlation between the viral load and the frequency of variation in total epitopes,anchor site and flank region. However, we didn’t observed a positive correlation between the viral load and the frequency ofvariation in non-anchor site. Conclusion There are relatively conservative in most CTL epitopes of Nef protein,the variationof flank region was more frequently than the anchor site in CTL epitope, the frequency of first amino acid mutation to upstreamand downstream of flank region is higher,the variation of amino acid sequence in flank region may be the main way of escapemutation of Nef protein.The relationship of the variation in CTL epitopes and the damage of viral fitness needs further study。
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