Yang S, Linette G P, Longerich S, Roberts B L, Haluska F G
Division of Hematology-Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
Cell Immunol. 2000 Aug 25;204(1):29-37. doi: 10.1006/cimm.2000.1695.
HLA-A2.1/K(b) transgenic mice (A2.1/K(b) mice) were used to investigate the processing of human gp100 melanoma antigen by murine antigen presenting cells (APC). Bone marrow-derived dendritic cells (DC) from A2.1/K(b) mice were transduced with adenovirus encoding human gp100 (Ad2/hugp100v2). The Ad2/hugp100v2-transduced DC express human gp100, as documented by immunoperoxidase staining. Flow cytometric analysis demonstrates that Ad vector transduction does not downregulate expression of several markers, including MHC class I. We show that Ad2/hugp100v2-transduced DC are recognized by peptide-specific, A2.1-restricted CTL, suggesting correct processing and presentation of the hugp100 antigen by murine DC. To assess dominance among the various A2.1-restricted epitopes encoded by hugp100, A2.1/K(b) transgenic mice were immunized with Ad2/hugp100v2-transduced DC. Resulting effector cytotoxic T lymphocytes (CTL) were assayed for peptide specificity using a panel of six synthetic peptides known to encode A2.1-restricted epitopes of human gp100 (denoted G154, G177, G209, G280, G457, G476). CTL obtained from Ad2/hugp100v2-transduced DC immunized A2.1/K(b) mouse lysed target cells presenting five of the six epitopes, supporting the observation that murine cells correctly process the hugp100 antigen. The immunogenicity of individual gp100 epitopes correlates with their binding affinity to A2.1. CTL generated from A2.1/K(b) mice immunized with Ad2/hugp100v2-transduced DC also specifically recognize A2.1(+)/gp100(+) human melanoma cells. These data suggest that murine APC process and present the same set of HLA-restricted peptides, similar to human APC. HLA transgenic mice serve as a useful model system to study class I-restricted epitopes of human tumor-associated antigens.
HLA - A2.1/K(b)转基因小鼠（A2.1/K(b)小鼠）被用于研究鼠源抗原呈递细胞（APC）对人gp100黑色素瘤抗原的加工处理。用编码人gp100的腺病毒（Ad2/hugp100v2）转导A2.1/K(b)小鼠骨髓来源的树突状细胞（DC）。免疫过氧化物酶染色证明，经Ad2/hugp100v2转导的DC表达人gp100。流式细胞术分析表明，腺病毒载体转导不会下调包括MHC I类在内的几种标志物的表达。我们发现，经Ad2/hugp100v2转导的DC可被肽特异性、受A2.1限制的CTL识别，这表明鼠源DC对hugp100抗原进行了正确的加工和呈递。为了评估hugp100编码的各种受A2.1限制的表位之间的优势，用经Ad2/hugp100v2转导的DC免疫A2.1/K(b)转基因小鼠。使用一组已知编码人gp100的受A2.1限制表位的六种合成肽（分别标记为G154、G177、G209、G280、G457、G476），对产生的效应细胞毒性T淋巴细胞（CTL）进行肽特异性检测。从经Ad2/hugp100v2转导的DC免疫的A2.1/K(b)小鼠获得的CTL裂解了呈递六种表位中五种表位的靶细胞，支持了鼠源细胞能正确加工hugp100抗原的观察结果。单个gp100表位的免疫原性与其对A2.1的结合亲和力相关。用经Ad2/hugp100v2转导的DC免疫A2.1/K(b)小鼠产生的CTL也能特异性识别A2.1(+)/gp100(+)人黑色素瘤细胞。这些数据表明，鼠源APC加工并呈递与人类APC相同的一组HLA限制肽。HLA转基因小鼠是研究人类肿瘤相关抗原I类限制表位的有用模型系统。
