Li Y, Sun G R, Zheng Q, Yoo D H, Bhardwaj N, Posnett D N, Crow M K, Friedman S M
Department of Medicine, Hospital for Special Surgery, New York 10021, USA.
Hum Immunol. 1996 Sep 1;49(2):85-95. doi: 10.1016/0198-8859(96)00062-6.
Several human TCR BV gene subfamilies, including BV3, BV14, and BV17S1, are single member genes but are overutilized among activated CD4+ synovial T cells in the rheumatoid arthritis (RA). To define the role of these TCR BV genes in the pathogenesis of disease, it is critical to characterize the genomic organization and the allelic variations of these genes. In this study we describe allelic variations of BV17S1 defined by restriction fragment length polymorphism (RFLP), single strand conformation polymorphism (SSCP), and amplification refractory mutation system (ARMS) analyses. A single nucleotide replacement (C/T) results in an amino acid substitution (F/L) in the leader and distinguishes BV17S11 from BV17S12. This nucleotide substitution was found to create a BsmAI restriction enzyme recognition site in BV17S12. Therefore genotypic analyses can be performed either by the SSCP or RFLP method. The analyses of 75 unrelated individuals show that the frequency for allele BV17S11 is 52.7% and for allele BV17S12 is 47.3%. Both alleles are functionally expressed and are distributed within CD4+/CD8+ T cell subsets. Another point mutation in the CDR2 region of BV17S1, which results in the amino acid replacement of Gln by His, originally identified form a cDNA clone, has now been confirmed as an allele by ARMS analysis using genomic DNA preparations and designated to as BV17S13. Screening of this CDR2 related variant among normal populations indicates that this is a rare allele (1 of 75). Although this variant may be of functional significance, the genotypic analysis and functional studies are difficult due to the low frequency of BV17S1*3. In an attempt to define a correlation between BV17S1 allelic usage and susceptibility to RA, the germline distribution of BV17S1 alleles *1 and *2 has been examined in a small number of RA patients and no skewed usage has been identified.
包括BV3、BV14和BV17S1在内的几个人类TCR BV基因亚家族是单成员基因，但在类风湿性关节炎（RA）中活化的CD4 + 滑膜T细胞中过度使用。为了确定这些TCR BV基因在疾病发病机制中的作用，表征这些基因的基因组组织和等位基因变异至关重要。在本研究中，我们描述了通过限制性片段长度多态性（RFLP）、单链构象多态性（SSCP）和扩增阻滞突变系统（ARMS）分析所定义的BV17S1的等位基因变异。单个核苷酸替换（C/T）导致前导序列中的氨基酸替换（F/L），并将BV17S11与BV17S12区分开来。发现该核苷酸替换在BV17S12中产生了一个BsmAI限制酶识别位点。因此，可以通过SSCP或RFLP方法进行基因型分析。对75名无关个体的分析表明，等位基因BV17S11的频率为52.7%，等位基因BV17S12的频率为47.3%。两个等位基因均有功能表达，并分布在CD4 + /CD8 + T细胞亚群中。最初从一个cDNA克隆中鉴定出的BV17S1的CDR2区域中的另一个点突变，导致氨基酸Gln被His取代，现在已通过使用基因组DNA制剂的ARMS分析确认为一个等位基因，并命名为BV17S13。在正常人群中筛选这种与CDR2相关的变体表明，这是一个罕见的等位基因（75人中1人）。尽管这种变体可能具有功能意义，但由于BV17S13的频率较低，基因型分析和功能研究都很困难。为了确定BV17S1等位基因使用与RA易感性之间的相关性，已在少数RA患者中检查了BV17S1等位基因1和*2的种系分布，未发现偏倚使用情况。
