Rescue of the immunotherapeutic potential of a novel T cell epitope in the Epstein–Barr virus latent membrane protein 2

Abstract

Epstein-Barr virus (EBV)-associated tumors express a limited number of viral antigens but most of them express the latent membrane protein 2 (LMP2). This article describes a peptide derived from LMP2 (residues 396-404, designated LLL) as a potentially useful vaccine. This peptide could at first be defined as an unlikely T cell target as it could not stabilize MHC surface expression in transporter associated with antigen-processing (TAP)-deficient cells. Nevertheless, T lymphocytes reactive to LLL were detected in the peripheral blood of four EBV-seropositive healthy individuals. We have constructed a chimeric molecule in which LLL was fused to the amino-terminal end of the beta(2) microglobulin (beta(2)m). Autologous dendritic cells constitutively expressing the LLLbeta(2)m molecule were capable of expanding in vitro HLA-A2-restricted anti-LLL T lymphocytes from the peripheral blood of one of the donors. These T lymphocytes exhibited cytolytic activity against target cells expressing the chimeric molecules as well as against EBV-infected lymphoblastoid cells expressing natural LLL-MHC complexes.

Chimerically fused antigen rich of overlapped epitopes from latent membrane protein 2 (LMP2) of Epstein–Barr virus as a potential vaccine and diagnostic agent

“…Compared with a whole protein vaccine, an epitope-based vaccine has the following advantages: it induces a conserved protective epitope-specific immune response without eliciting an autoimmune reaction or immune suppression; multi-epitope vaccines containing T-and B-cell epitopes can induce broader humoral and cellular immune responses in the host 19 ; and the combination of different HLA-restricted CTL epitopes in one vaccine can be used to accelerate the effect of cellular immune responses against certain tumors due to the presence of HLA allelic variants that bind to distinct sets of peptides. 20 Recently, several Th-and HLA-restricted CTL epitopes in LMP2 have been identified, [21][22][23] and our group has reported B-cell epitopes of EBV-LMP2. 24 In this study, we systematically screened CTL, Th, and B-cell epitopes within LMP2 using bioinformatics.…”

Immune response of mice to a latency membrane protein 2 multiepitope antigen of Epstein-Barr virus applied as DNA vaccine and/or peptide vaccine

“…LMP2 is considered to be a potential target for an immunotherapy to EBV-associated malignancies because it can induce autologous cytotoxic T lymphocytes in vitro (Lalonde et al, 2007;Wang et al, 2009;Pan et al, 2006;Duraiswamy et al, 2004). Straathof et al (2005) synthesized an overlapping 15-mer peptide covering the whole LMP2 sequence, and 25 LMP2-specific CTL cell lines were obtained by screening these peptides by cytotoxicity assay.…”

Immunosuppressive Effect of Isopropanol: Down-Regulation of Cytokine Production Results from the Alteration of Discrete Transcriptional Pathways in Activated Lymphocytes

“…This parental version of pRRL-5pme also carries the Zeocin resistance gene driven by the promoter of the human phosphoglycerokinase gene. Lentiviral supernatants were generated in 293T cells by transient transfection (11). Three plasmids, pMDLg/RRE, pRSV-rev, and pMD.VSV-G, were cotransfected with pLViluc.…”

“…The cytotoxic activity was analyzed in standard 4-h 51 Cr release assays as reported elsewhere (11). The targets were labeled with Na 51 CrO 4 for 2 h at 37°C.…”