Identification of novel CTL epitopes of CMV-pp65 presented by a variety of HLA alleles

Abstract

Cytomegalovirus (CMV)-specific T-cell immunity plays an important role in protection from CMV disease in immunocompromised patients. Identification of cytotoxic T-lymphocyte (CTL) epitopes is essential for monitoring T-cell immunity and also for immunotherapy. In this and previous studies, CMV-pp65-specific CTL lines were successfully generated from all of 11 CMV-seropositive healthy donors, using pp65-transduced CD40

Selection of CMV-specific CD8+ and CD4+ T cells by mini-EBV-transformed B cell lines

“…HLA alleles that match with those of the T cell donor are written in boldface. we identified the HLA-A*11-restricted epitope ATVQGQNLK and the HLA-Cw*12-restricted epitope VAFTSHEHF, both recently described by Kondo et al [13], to be target epitopes of our T cell clones. For donor 45, the T cell clones displaying the novel HLA-B*14 restriction were analyzed with the peptide library (Fig.…”

“…In a pilot experiment, we used cells from donor 1, with an HLA type for which CD8 + T cell epitopes of pp65 and an EBV latent cycle protein were known (the A1-restricted pp65 epitope YSE, and the B8-restricted EBNA3A epitope QAK; see also Table 1). To quantify functional epitope- For an overview of known CMV pp65 CD8 + epitopes, see [13,29]; for known EBV epitopes, see [30]. b) Epitopes identified in this study.…”

“…CMV-infected fibroblasts as APC [6] have generally been replaced either by unseparated PBMC [5] or by defined professional APC populations such as dendritic cells (DC) [9][10][11][12] or activated B cells [13,14]. The CMV antigenic stimulus has been provided by infection of APC with recombinant viral vectors introducing relevant CMV antigens [9,10,13,14], loading with epitope peptides [12] or CMV protein lysates [5,11].…”

Retroviral vector backbone immunogenicity: identification of cytotoxic T-cell epitopes in retroviral vector-packaging sequences

“…21,22 With all of eight CMV-seronegative donors, however, we failed to generate pp65-specific CTL lines. Thus, to enhance the efficiency of induction of pp65-specific CTLs, we cultured CD8 T cells in the presence of interleukin-12, which is known to be an immunostimulatory cytokine.…”

“…22 The HLA-B*4403-restricted CTL clone 8C7 recognized transfectants expressing aa 1-169 or longer, but not 1-138, indicating that the epitope fully or partially lies between aa 139 and aa 169. With the aid of a computer algorithm, 23 peptides presented by HLA-B*4403 within the localized region were predicted ( Table 2).…”