Use of combinatorial peptide libraries to construct functional mimics of tumor epitopes recognized by MHC class I-restricted cytolytic T lymphocytes.
Use of combinatorial peptide libraries to construct functional mimics of tumor epitopes recognized by MHC class I-restricted cytolytic T lymphocytes.
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DOI：
10.1084/jem.184.1.121
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发表时间：
1996-07-01
期刊：
影响因子：
--
通讯作者：
Chen L
中科院分区：
文献类型：
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作者：
Blake J;Johnston JV;Hellström KE;Marquardt H;Chen L
主要组织相容性复合体（MHC） I类分子在肿瘤细胞上呈现的细胞溶解性T淋巴细胞（CTL）表位的鉴定对于设计主动免疫治疗至关重要。我们描述了在两个MHC锚定位置使用具有确定氨基酸的组合肽文库来搜索小鼠淋巴瘤EL4特异性的H-2Db和kb限制性CTL识别的表位。采用迭代法筛选文库，将16个氨基酸分为3组和3亚组：α (AL， VT， FY)；β (GS， P， DE)；（KR， H， NQ）在文库合成中，每个组和亚组在单个肽位置的比例发生了变化，这些变化对CTL活性的影响通过敏感的RMA-S细胞试验来测量。从原始文库中推断出单个H-2Db表位模拟物，其包含bbbb2 × 10(8)个潜在肽，比原始文库的效力至少高9倍。用该肽免疫同基因小鼠，可诱导裂解EL4细胞的CTL以及用从EL4细胞Db分子中分离的肽脉冲的RMA-S细胞，这表明模仿肽与自然加工的CTL表位在功能上相似。此外，这种CTL的过继转移对EL4作为腹水肿瘤的小鼠具有治疗作用。同一肿瘤的两个h - 2kb限制性表位模拟物也被鉴定出来。我们的方法代表了构建MHC i类限制性靶点的新途径，这些靶点可以作为癌症主动免疫治疗的免疫原。
Identification of cytolytic T lymphocyte (CTL) epitopes presented by major histocompatibility complex (MHC) class I molecules on tumor cells is critical for the design of active immunotherapy. We describe the use of combinatorial peptide libraries with defined amino acids in two MHC anchor positions to search for epitopes that are recognized by H-2Db- and Kb-restricted CTL specific for the mouse lymphoma EL4. An iterative strategy was used for screening libraries in which 16 amino acids were divided into 3 groups and 3 subgroups: alpha (AL, VT, FY); beta (GS, P, DE); gamma (KR, H, NQ). The proportions of each group and subgroup at individual peptide positions were changed in the library synthesis, and the effect of these changes on CTL activity was measured in a sensitive RMA-S cell assay. A single H-2Db epitope mimic was deduced from the original library that contained > 2 x 10(8) potential peptides and was at least 9 logs more potent than the original library. Immunization of syngeneic mice with this peptide elicited CTL that lysed EL4 cells as well as RMA-S cells pulsed with peptides isolated from Db molecules of EL4 cells, indicating functional similarity between the mimicking peptide and the naturally processed CTL epitope. Furthermore, adoptive transfer of such a CTL line had a therapeutic effect in mice with EL4 established as an ascites tumor. Two H-2Kb-restricted epitope mimics of the same tumor were also identified. Our method represents a novel approach for the construction of MHC class I-restricted targets that can serve as immunogens for active immunotherapy of cancer.