Cytotoxic T lymphocyte escape variants, induced mutations, and synthetic peptides define a dominant H-2Kb-restricted determinant in simian virus 40 tumor antigen.
Cytotoxic T lymphocyte escape variants, induced mutations, and synthetic peptides define a dominant H-2Kb-restricted determinant in simian virus 40 tumor antigen.
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细胞毒性 T 淋巴细胞逃逸变异、诱导突变和合成肽定义了猿病毒 40 肿瘤抗原中的显性 H-2Kb 限制性决定簇。
DOI：
10.1006/viro.1995.1139
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发表时间：
1995
期刊：
影响因子：
3.7
通讯作者：
Tevethi,SS
中科院分区：
文献类型：
--
作者：
Mylin,LM;Deckhut,AM;Bonneau,RH;Kierstead,TD;Tevethia,MJ;Simmons,DT;Tevethi,SS
用猴病毒40大T抗原（SV40 T ag）转化的同基因细胞免疫C57BL/6小鼠，可诱导T抗原特异性细胞毒性T淋巴细胞（CTL）的产生，CTL受主要组织相容性I类抗原H-2Dband H-2Kb的限制。先前的研究表明，h - 2db限制性CTL反应指向SV40 T抗原中至少三个不同的表位（I， II/III和V），这些表位已通过缺失诱变和重叠合成肽精确定位。虽然体内对SV40 T抗原的CTL反应以h - 2kbi类抗原为主，但h - 2kb限制性表位的确切位置尚不清楚，h - 2kb限制性表位是否存在多重性尚不清楚。在本研究中，我们利用T抗原缺失、点突变体和合成肽确定了sv40特异性h - 2kb限制性CTL克隆Y-4的最小识别表位为T抗原残基404-411。对三个独立分离的CTL克隆Y-4逃逸变异体中表达的T抗原编码残基404-411区域的DNA序列分析发现了能够取消CTL识别的失活突变。通过限制稀释分析对CTL前体（CTLp）频率的估计显示，在h - 2b小鼠中，表位IV特异性的CTLp占完整T抗原引起的总CTL反应的很大比例。用表达残基404-411缺失的T抗原衍生物的细胞免疫B6小鼠，发现IV位点是T抗原中唯一具有免疫优势的h - 2kb限制性表位。
Immunization of C57BL/6 mice with syngeneic cells transformed by simian virus 40 large T antigen (SV40 T ag) induces the generation of T antigen-specific cytotoxic T lymphocytes (CTL) which are restricted by the major histocompatibility class I antigens H-2Dband H-2Kb. Previous studies have shown that the H-2Db-restricted CTL response is directed to at least three distinct epitopes (I, II/III, and V) in the SV40 T antigen which have been precisely mapped using deletion mutagenesis and overlapping synthetic peptides. Although in vivo the CTL response to SV40 T antigen is dominated by the H-2Kbclass I antigen, the precise location of the H-2Kb-restricted epitope(s) was not known, and whether there was multiplicity of H-2Kb-restricted epitopes remained unclear. In this study, we have defined the minimal recognition epitope for the SV40-specific H-2Kb-restricted CTL clone Y-4 as T antigen residues 404-411 by using T antigen deletion and point mutants and synthetic peptides. DNA sequence analysis of the region encoding residues 404-411 from the T antigens expressed in three independently isolated CTL clone Y-4 escape variants identified inactivating mutations capable of abrogating CTL recognition. Estimation of CTL precursor (CTLp) frequencies by limiting dilution analysis revealed that CTLp specific for epitope IV represent a large percentage of the total CTL response elicited by the intact T antigen in H-2bmice. Immunization of B6 mice with cells expressing a T antigen derivative deleted of residues 404-411 revealed that site IV represents the only immunodominant H-2Kb-restricted epitope within T antigen.