Cross-recognition of a mouse H-2-peptide complex by human HLA-restricted cytotoxic T cells.
Epstein-Barr virus (EBV)-specific human cytotoxic T lymphocyte (CTL) lines from a virus-immune HLA-A11+ donor CMc produced significant lysis of transfected mouse P815 target cells (H-2d background) expressing an introduced HLA-A11 heavy chain gene and the EBV gene encoding latent membrane protein (LMP). To identify the target epitope being recognized, HLA-A11+ transfectants of P815/A11) were pre-exposed to synthetic peptides corresponding to fragments of the LMP sequence and the cells then tested for lysis by CMc effectors; untransfected P815 parent cells were included in these assays as control recipients of the same peptides. Unexpectedly, we identified a peptide preparation (corresponding to LMP residues 124-137) which specifically sensitized not only P815/A11 cells but also the parental P815 cells to lysis. Four independent anti-EBV CTL lines derived from donor CMc gave the same result and single-cell cloning confirmed that lysis was mediated by a subset of the HLA-A11-restricted EBV-specific CTL clones which dominate CMc effector populations. Two lines of evidence indicated that peptide presentation to the human CTL was occurring through H-2Kd molecules on the surface of P815/A11 and P815 cells: (a) a monoclonal antibody reactive with H-2Kd specifically blocked the lysis of both P815/A11 and P815 peptide-treated targets, and (b) on an extended target cell panel, peptide-mediated sensitization was also obtained with a second H-2d mouse line A20.2J and with an H-2Kd transfectant of the H-2k line R1E. This work has therefore identified EBV-specific HLA-A11-restricted human CTL which show fortuitous cross-recognition of a synthetic peptide in the context of a mouse H-2Kd molecule. Such potential for xenogeneic cross-reactivity needs to be borne in mind in situations where the target specificity of human CTL is being analyzed on HLA gene-transfected murine target lines.
Department of Cancer Studies, University of Birmingham, GB.
R J
RJ
Murray
J M
JM
Brooks
A B
AB
Rickinson
M
M
Rowe
D000595:Amino Acid Sequence; D000956:Antigens, Viral / Q000276:immunology*; D002999:Clone Cells; D000939:Epitopes; D006183:H-2 Antigens / Q000502:physiology*; D006681:HLA-D Antigens / Q000502:physiology*; D004854:Herpesvirus 4, Human / Q000276:immunology; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology*; D013045:Species Specificity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014763:Viral Matrix Proteins
D000956:Antigens, Viral; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D000939:Epitopes; D006183:H-2 Antigens; D006681:HLA-D Antigens; D010455:Peptides; D014763:Viral Matrix Proteins