Murray R J, Brooks J M, Rickinson A B, Rowe M
Department of Cancer Studies, University of Birmingham, GB.
Eur J Immunol. 1990 Mar;20(3):659-64. doi: 10.1002/eji.1830200329.
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.
来自病毒免疫的HLA - A11阳性供体CMc的爱泼斯坦-巴尔病毒（EBV）特异性人细胞毒性T淋巴细胞（CTL）系，对转染了导入的HLA - A11重链基因和编码潜伏膜蛋白（LMP）的EBV基因的小鼠P815靶细胞（H - 2d背景）产生了显著的裂解作用。为了确定被识别的靶表位，将P815/A11的HLA - A11阳性转染细胞预先暴露于与LMP序列片段相对应的合成肽，然后检测这些细胞被CMc效应细胞裂解的情况；未转染的P815亲本细胞作为相同肽的对照接受者包含在这些检测中。出乎意料的是，我们鉴定出一种肽制剂（对应于LMP的124 - 137位残基），它不仅使P815/A11细胞，而且使亲本P815细胞对裂解敏感。来自供体CMc的四个独立的抗EBV CTL系给出了相同的结果，单细胞克隆证实裂解是由HLA - A11限制性EBV特异性CTL克隆的一个亚群介导的，这些克隆在CMc效应细胞群体中占主导地位。有两条证据表明，人CTL对肽的呈递是通过P815/A11和P815细胞表面的H - 2Kd分子发生的：（a）一种与H - 2Kd反应的单克隆抗体特异性地阻断了P815/A11和经肽处理的P815靶细胞的裂解，（b）在一个扩展的靶细胞组中，用第二个H - 2d小鼠系A20.2J和H - 2k系R1E的H - 2Kd转染细胞也获得了肽介导的致敏作用。因此，这项工作鉴定出了EBV特异性的HLA - A11限制性人CTL，它们在小鼠H - 2Kd分子的背景下对一种合成肽表现出偶然的交叉识别。在利用HLA基因转染的小鼠靶细胞系分析人CTL的靶特异性的情况下，需要牢记这种异种交叉反应的可能性。
