Computational prediction and identification of Epstein-Barr virus latent membrane protein 2A antigen-specific CD8+ T-cell epitopes.

Epstein-Barr virus (EBV) associated nasopharyngeal carcinoma (NPC) is a high incidence tumor in Southeast Asia. Among EBV encoded proteins, latent membrane protein 2A (LMP2A) is an important antigen for T cell therapy of EBV. In this study, we predicted six HLA-A2 restricted CTL candidate epitopes of LMP2A by SYFPEITHI, NetMHC and MHCPred methods combined with the polynomial method. Subsequently, biological functions of these peptides were tested by experiments in vitro. In ELISPOT assay, the positive response of the LMP2A specific CTL stimulated by three (LMP2A(264-272), LMP2A(426-434) and LMP2A(356-364)) of six peptides respectively showed that the numbers of spots forming cells (SFC) ranged from 55.7 to 80.6 SFC/50,000 CD8(+) T cells and the responding index (RI) ranged from 5.4 to 7. These three epitope-specific CTLs could effectively kill specific HLA-A2-expressing target cells. As a result, LMP2A(264-272) (QLSPLLGAV), LMP2A(426-434) (CLGGLLTMV) and LMP2A(356-364) (FLYALALLL) were identified as LMP2A-specific CD8(+) T-cell epitopes. It would be useful to clarify immune response toward EBV and to develop a vaccine against EBV-correlative NPC.