Onda K, Kashiwagi N, Obata F
Department of Immunology, Kitasato University School of Medicine, Sagamihara, Japan.
Scand J Immunol. 1996 May;43(5):519-24. doi: 10.1046/j.1365-3083.1996.d01-67.x.
In order to analyse the diversity of T-cell receptors (TCRs) expressed by the T-cell population activated by allogeneic HLA-DR stimulation, TCR beta cDNA was synthesized from mRNA of human CD4+ T cells that had been stimulated in a primary mixed lymphocyte reaction (MLR). The TCR beta cDNA was amplified by the polymerase chain reaction (PCR), subjected to bacterial cloning, and sequenced from V beta through J beta. Twenty-six different V beta and 10 different J beta segments were detected among 56 randomly selected cDNA clones. Occurrences of V beta 17.1 and J beta 1.5 were higher than those found in the CD4+ T-cell population activated with a CD3-specific antibody. A total of 53 different CDR3 sequences, two of them occurring more than once, were detected among the 56 cDNA clones. In order to estimate the degree of CDR3 diversity, amino acid similarity in the CDR3 region of the cDNA was calculated and compared with those of the anti-CD3-activated T-cell sequences as well as those of various published T-cell clone sequences, each directed to either alloantigens or single antigenic peptides. It was found that the similarity score among CDR3 sequences obtained from the MLR (56.4 +/- 10.3) was comparable to those of anti-CD3-activated T cells (55.7 +/- 10.7) and those of T-cell clones directed toward alloantigens (range, 48.4 +/- 12.4-59.4 +/- 13.1), but significantly smaller than those of T-cell clones directed toward single antigenic peptides such as those derived from myelin basic protein (75.6 +/- 17.9) and cytochrome c (76.9 +/- 20.5). These results provide quantitative proof that TCRs of T cells activated by primary allogeneic HLA-DR stimulation have a larger diversity than those recognizing single antigenic peptides.
为了分析同种异体 HLA - DR 刺激激活的 T 细胞群体所表达的 T 细胞受体（TCR）的多样性，从在初次混合淋巴细胞反应（MLR）中受到刺激的人 CD4⁺T 细胞的 mRNA 合成 TCRβ cDNA。通过聚合酶链反应（PCR）扩增 TCRβ cDNA，进行细菌克隆，并从 Vβ 到 Jβ 进行测序。在 56 个随机选择的 cDNA 克隆中检测到 26 种不同的 Vβ 和 10 种不同的 Jβ 片段。Vβ17.1 和 Jβ1.5 的出现频率高于用 CD3 特异性抗体激活的 CD4⁺T 细胞群体中的频率。在 56 个 cDNA 克隆中总共检测到 53 种不同的 CDR3 序列，其中两种出现不止一次。为了估计 CDR3 的多样性程度，计算了 cDNA 的 CDR3 区域中的氨基酸相似性，并与抗 CD3 激活的 T 细胞序列以及各种已发表的针对同种异体抗原或单一抗原肽的 T 细胞克隆序列的氨基酸相似性进行比较。发现从 MLR 获得的 CDR3 序列之间的相似性得分（56.4±10.3）与抗 CD3 激活的 T 细胞的相似性得分（55.7±10.7）以及针对同种异体抗原的 T 细胞克隆的相似性得分（范围为 48.4±12.4 - 59.4±13.1）相当，但明显小于针对单一抗原肽（如源自髓鞘碱性蛋白的肽和细胞色素 c）的 T 细胞克隆的相似性得分（分别为 75.6±17.9 和 76.9±20.5）。这些结果提供了定量证据，表明初次同种异体 HLA - DR 刺激激活的 T 细胞的 TCR 比识别单一抗原肽的 TCR 具有更大的多样性。
