正常人T细胞和胸腺细胞中多种新的TCRδRec基因重排

利用巢式或半巢式PCR扩增10例正常人外周血单个核细胞(PBMC)、4例分选CD3~+细胞和7例正常胸腺细胞DNA中TCR δRec区与Jδ1、Dδ3和Ja重排的基因片段,分析正常人外周血T细胞和胸腺细胞中TCR δRec基因重排情况。克隆性PCR产物进一步进行核苷酸序列分析确定其重排位置。结果发现了4种新的TCR δRec重排,包括TCR δRec_(149321)-Jδ1、TCRδRec_(149820)-Jδ1、TCR δRec_(151657)(Nx)-Ja和TCR δRec_(153199)-Jδ1等,其中以TCR δNx的重排最多见,通过利用不同模板DNA的PCR分析发现δRec重排在外周血和胸腺细胞中有所不同。结果显示TCR δNx-Jδ1重排在成熟和不成熟T细胞发生频率均较高,而TCR δNx-Dδ3重排在不成熟T细胞中发生率较高。但所有重排均不表达于mRNA中。本研究结果为TCR δ基因重排的研究补充了一些新的数据。

Some New TCR δRec Gene Rearrangements in Peripheral Blood T Cells and Thy mocytes of Normal Individuals

In order to analyze the TCR SRec gene rearrangements in peripheral blood T cells and thymocytes of normal individuals, the rearrangement segments of TCR SRec gene with JS1 ., DS3 or ψJa in the genomic DNA from peripheral blood mononuclear cells (PBMC )from 10 cases of normal individuals were amplified, and the CD3+ cells were sorted from peripheral blood of 4 cases and thymocytes from 7 cases by using semi-nested or nested were PCR. The clonal PCR products were further sequenced to define the position of rearrangements, and the expression of the rearrangement genes were detected by RT-PCR. The results showed that 4 new TCR SRec rearrangements were detected, they were TCR 8Rec14932i-Jδl, TCR SRec149820-Jδ1 , TCR oRec151657(Nx )-δJa and TCR δRec153199-Jδ1 in which the TCR SNx was found in most cases. The frequency of the SRec rearrangements was found to be different among PBMC and thymocytes by anal-ysis of PCR with different amounts of DNA. The results indicated that the TCR SNx-JSl was the most frequent rearrangement in mature and immature T cells, whereas TCR δNx-Dδ3 more frequently rearranged in immature T cells. No positive product was detected by RT-PCR. The results in this study could provide some new data for the research of the TCR S gene rearrangements.