STUBER, G and DILLNER, J and MODROW, S and WOLF, H and SZEKELY, L and KLEIN, G and KLEIN, E (1995) HLA-A0201 AND HLA-B7 BINDING PEPTIDES IN THE EBV-ENCODED EBNA-1, EBNA-2 AND BZLF-1 PROTEINS DETECTED IN THE MHC CLASS-I STABILIZATION ASSAY - LOW PROPORTION OF BINDING MOTIFS FOR SEVERAL HLA CLASS-I ALLELES IN EBNA-1. INTERNATIONAL IMMUNOLOGY, 7 (4). pp. 653-663. ISSN 0953-8178,
Full text not available from this repository.Abstract
B lymphocytes immortalized with EBV in vitro, lymphoblastoid cell lines (LCL), express eight EBV-encoded proteins, E8V nuclear antigens -1 to -6 (EBNA-1 to -6), and latent membrane proteins 1 and 2 (LMP 1 and 2). After appropriate stimulations of blood lymphocytes from seropositive individuals, MHC-restricted cytotoxic T cells (CTL), which lyse LCL cells, can be generated in vitro. Such CTLs can recognize EBNA-2 to -6, and LMP 1 and 2, but not EBNA-1-derived peptides presented on the cell surfaces. We posed the question whether this exceptional feature of EBNA-1 is due to lack of MHC class I binding peptides. A computer search for 11 human leukocyte antigen (HLA) alleles showed that EBNA-1 has a lower number and lower proportion of relevant binding motifs to several alleles than EBNA-2 to -6 and LMP 1 and 2. The low motif numbers in EBNA-1 is in line with its apparent failure to generate a CTL response, and it may be the consequence of immunoselection allowing the existence of EBV genome-carrying B cells in the immunocompetent hosts. The binding capacities of synthetic peptides of EBNA-1 and -2 and of the immediate early lytic cycle protein BZLF-1 to HLA-A0201 (A2) and HLA-B7 molecules were tested in an MHC stabilization assay. The peptide transporter-deficient T2 line, which expresses a low level of HLA-A2 and its HLA-B7 transfectant subline, were used for this purpose because specifically bound peptides elevate the surface expression of these MHC molecules. Of five synthetic nonamer EBNA-1 peptides which include the relevant binding motif, four bound to A2. In a series of 20-amino acid-long overlapping EBNA-1 peptides none showed binding to A2, while eight peptides bound to B7. Two 20-amino acid-long EBNA-2 and seven BZLF-1 peptides were identified as A2 binders, and four EBNA-2 and eight BZLF-1 peptides bound to 87. Thus, we have excluded the possibility that the inability of the EBNA-1 protein to generate HLA-restricted CTLs could be due to the lack of HLA class I binding peptides in its sequence. The finding that several EBNA-1 peptides could bind to these two HLA molecules does not, however, necessarily reflect the natural situation because the peptides may not be processed and/or transported to the cell surfaces. We have stimulated lymphocytes of healthy donors with relevant HLA types with the autologous LCL. The resulting auto-LCL-reactive culture did not lyse autologous phytohaemagglutinin blasts coated with the binder peptides, and we could not generate auto-LCL-specific CTLs by stimulation of lymphocytes with these peptides.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | EPSTEIN-BARR-VIRUS; MAJOR HISTOCOMPATIBILITY COMPLEX; VIRAL PEPTIDES; NASOPHARYNGEAL CARCINOMA; MOLECULES; ANTIGEN; IDENTIFICATION; LYMPHOCYTES; ANTIBODIES; TRANSPORT; BINDING MOTIFS; CTL EPITOPE; MOTIF SEARCH; PEPTIDE BINDING |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:38 |
| URI: | https://pred.uni-regensburg.de/id/eprint/52663 |
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