TRGV and TRDV repertoire distribution and clonality of T cells from umbilical cord blood
TRGV and TRDV repertoire distribution and clonality of T cells from umbilical cord blood
复制标题
DOI：
10.1016/j.trim.2008.10.010
复制
发表时间：
2009-01-01
影响因子：
1.5
通讯作者：
Cai, Dongqing
中科院分区：
文献类型：
--
作者：
Li, Yangqiu;Chen, Shaohua;Cai, Dongqing
脐带血作为造血干细胞的重要来源，在异基因移植、特异性CTL应答和免疫治疗中有着广泛的应用。我们先前分析了来自脐带血的T细胞中T细胞受体亚家族T细胞受体α和β可变区（TRAV）和（TRBV）的分布和克隆性。最近的数据表明，γ 8（+）T细胞可能在介导干细胞移植后的移植物抗白血病效应和抗癌反应中起重要作用。为了进一步表征CB T细胞的库，通过FACS检查CB中α β（+）和γ δ（+）T细胞的频率。应用RT-PCR和基因扫描技术，对16份CB标本的单个核细胞（MC）中4个TRGV和8个TRDV亚家族基因的CDR3进行了分析。为了确定TRGV亚家族基因的表达水平，我们通过实时PCR对TRGVI-III亚家族进行定量分析。在CB中观察到低百分比的CD3（+）TCR γ δ（+）细胞。TRGVI、TRGVII和TRGVIII在CBMCs中的表达频率分别为93.75%、81.25%和56.25%。CBMCs表达的TRDV亚家族数的平均值高于成人外周血组。在CB中表达频率最高的是TRDV 1（100%）、TRDV 2（93.75%）、TRDV 8（93.75%）和TRDV 3（81.25%）。CBMCs中TRDV5和TRDV8的频率显著高于PBMCs。10份CB样品的TRGV和TRDV亚家族的PCR产物大多数呈现多克隆重排模式，而6份CB样品的PCR产物中有1~2个呈现寡克隆或双克隆模式。与此相反，10名成人健康对照中有9名的PCR产物分别含有不同TRGV或TRDV亚家族的至少一个寡克隆峰。TRGV亚家族在CBMCs中的表达水平为TRGVI> TRGVIII> TRGVII，而在PBMCs中的表达水平为TRGVII> TRGVI> TRGVIII。总之，我们的结果表明在CB γ δ（+）T细胞中使用多克隆和更多样化的TRDV片段。发现CB T细胞中TRGV表达水平的模式与PB T细胞中的模式完全不同。这些发现显然是第一次报告的抑制模式TRGV剧目在CB。它还提供了中国受试者脐带血T细胞中TRGV和TRDV总体库和TRGVI-III表达水平的详细概况。CB和PB之间观察到的差异的生物学意义目前尚不清楚。然而，这项研究将有助于更好地了解细胞免疫功能，更有效地利用CB的治疗潜力。(C)2008 Elsevier B.V.保留所有权利。
Umbilical cord blood (CB) has been used as a valuable source of hematopoietic stem cells for allogeneic transplantation, specific CTL response and immunotherapy for decades. We previously analyzed the distribution and clonality of T-cell receptor alpha and beta variable region (TRAV) and (TRBV) of the subfamily T cell receptors in T cells from umbilical cord blood. Recent data indicated that gamma 8(+) T cells may play an important role in mediating the graft versus leukemia effect after stem cells transplantation and in anticancer response. In order to further characterize the repertoire of CB T-cells, the frequency of alpha beta(+) and gamma 8(+) T cells were examined in CB by FACS. The CDR3 size of 4 TRGV and 8 TRDV subfamily genes were analyzed in mononuclear cells (MCs) from 16 CB samples, using RT-PCR and genescan technique. To determine the expression level of TRGV subfamily genes, we performed quantitative analysis of TRGVI-III subfamilies by real-time PCR. Low percentage of CD3(+)TCR gamma delta(+) cells was observed in CB. The frequency of expression in TRGVI, TRGVII and TRGVIII in CBMCs was 93.75%, 81.25% and 56.25%, respectively. The mean value of the number of expressed TRDV subfamilies in CBMCs is higher than that from adult peripheral blood (PB) group. The frequently expressed members in CB were TRDV1 (100%), TRDV2 (93.75%), TRDV8 (93.75%) and TRDV3 (81.25%), respectively. The frequencies of TRDV5 and TRDV8 in CBMCs were significantly higher than those from PBMCs. Most of the PCR products of TRGV and TRDV subfamilies from 10 CB samples displayed polyclonal rearrangement pattern, whereas one or two PCR products from 6 CB samples showed oligoclonality or biclonality. In contrast, PCR products from 9 of 10 adult healthy controls contained at least an oligoclonal peak in different TRGV or TRDV subfamilies respectively. The pattern of TRGV subfamily expression level in CBMCs was TRGVI>TRGVIII>TRGVII, and in contrast, TRGVII>TRGVI>TRGVIII was found in PBMCs. In conclusion, our results indicate polyclonal and more diverse TRDV segment usage in CB gamma delta(+) T-cells. The pattern of TRGV expression levels in CB T cells was found to be quite different from the one in PB T cells. These findings are apparently the first report regarding the repression pattern of TRGV repertoire in CB. It also provides a detailed profile of the global TRGV and TRDV repertoire and TRGVI-III expression levels in cord blood T cells in Chinese subjects. The biological significance of the differences observed between CB and PB is at present obscure. However, this study will definitively contribute to understand the cellular immune features better and to exploit more efficiently the therapeutic potentials of CB. (C) 2008 Elsevier B.V. All rights reserved.