Shirwan H, Ohanjanian M, Burcham G, Makowka L, Cramer D V
Department of Surgery, Cedars-Sinai Research Institute, Los Angeles, CA 90048.
J Immunol. 1993 Mar 15;150(6):2295-304.
We have sequenced 22 TCR-alpha clones isolated from two cDNA libraries derived from rat thymocytes and heart allograft-infiltrating lymphocytes. Sixteen different V alpha and 17 J alpha genes were characterized in these clones. The V alpha genes could be divided into nine subfamilies, each containing from one to three members. Nucleotide sequence comparisons to mouse alpha genes revealed the existence of mouse homologues for all the J alpha s and 8 of 9 V alpha subfamilies. One of the rat V alpha subfamilies appeared to have no known mouse counterpart. Southern blot analysis of germ-line DNA with cDNA probes specific for six different subfamilies demonstrated the existence of two to nine V alpha genes per subfamily. A minimum number of 35 V alpha genes was estimated for the nine rat subfamilies characterized. These analyses also detected two different RFLP patterns among five different inbred rat strains, including strain-specific loss of hybridization bands for some V alpha, indicating that deletion events may have occurred in the rat alpha gene locus. The characterization of rat TCR V alpha genes should facilitate a better understanding of T cell role in pathologic conditions such as autoimmune diseases and graft rejection.
我们对从两个cDNA文库中分离出的22个TCR-α克隆进行了测序，这两个文库分别来自大鼠胸腺细胞和心脏同种异体移植浸润淋巴细胞。在这些克隆中鉴定出了16种不同的Vα基因和17种Jα基因。Vα基因可分为9个亚家族，每个亚家族包含1至3个成员。与小鼠α基因的核苷酸序列比较显示，所有Jα基因和9个Vα亚家族中的8个都存在小鼠同源物。大鼠的一个Vα亚家族似乎没有已知的小鼠对应物。用针对6个不同亚家族的cDNA探针进行种系DNA的Southern印迹分析表明，每个亚家族存在2至9个Vα基因。估计已鉴定的9个大鼠亚家族中至少有35个Vα基因。这些分析还在5种不同的近交大鼠品系中检测到两种不同的RFLP模式，包括某些Vα杂交带的品系特异性缺失，表明大鼠α基因座可能发生了缺失事件。大鼠TCR Vα基因的鉴定应有助于更好地理解T细胞在自身免疫性疾病和移植排斥等病理状况中的作用。
