Prediction And Comparative Study Of HLA-A~*0201-restricted CTL Epitopes Of Influenza A H1N1 Virus

Objective:To predict and compare the similarities and differences of HLA-A*0201-restricted cytotoxic T lymphocyte (CTL) epitopes between the influenza A virus (H1N1), avian influenza virus (H5N1) and human influenza virus (H3N2), in order to provide useful data for the investigation and application of influenza vaccines.Methods:The protein sequences of the influenza A virus (H1N1), avian influenza virus (H5N1) and human influenza virus (H3N2) were retrived from GenBank. And the sequence homology was analyzed using DNAMAN. SYFPEITHI was used to predict the CTL epitopes of these proteins, and the similarities and differences of these epitopes were analyzed.Results:After aligning the protein sequences of the H1N1, H5N1 and H3N2 viruses using DNAMAN, we found that almost of the protein sequences had a similarity over 90% except the following three proteins:HA, NA and NS. From this result we deduced that there was problely antigen cross-reaction between three viruses. The potential HLA-A*0201-restricted CTL epitopes were predicted using SYFPEITHI and the top 8 CTL epitopes from all the prediction epitopes were slected for further analysis. These epitopes were listed in tables. It was notable that, except the HA and NA, there were many identical and similar epitopes between the three viruses. Furthermore, among the epitopes we have predicted, there are fourteen epitopes that have been indexed by the Immune Epitope Database (IEDB). This result confirmed that there was antigen cross-reaction between the three above viruses. The epidemic distribution map announced by CDC conveyed that influenza A H1N1 virus was firstly origined and then transmitted from the north America, while at the same time we found that the avain influenza was hardly happened, suggesting that there was some relationships between them.Conclusion There exists an obvious cross-reaction among the three kinds of virus antigen,ΔThis work was supported by the grant from the Major State Basic Research Development Program of China (973 Program) (2010CB833603) and the Fundamental Research Funds for the Central Universities (21609403). which explained, at least in part, why the population infected by influenza A H1N1 virus had mild symptoms. Furthermore, these results suggested that human influenza vaccine inoculation would be helpful for the relief of the symptoms of H1N1 virus infection.