REARRANGEMENT AND EXPRESSION OF T CELL RECEPTOR β GENE IN HUMAN HEMOPOIETIC CELL LINES AND PRIMARY CELLS FROM ACUTE LYMPHOCYTIC LEUKEMIAS

Using Southern blot, Northern blot and Quick blot methods, we examined the rearrangement and expression of TCR βgene in four early differentiation stage cell lines from human hemopoietic system, namely HL-60, Jurkat, Daudi and Raji cells as well as lymphocytes from 17 acute lymphocytic leukemia （ALL） patients. The results showed. Ⅰ) Rearrangement of TCR βgene was seen in Jurkat cells. A germline pattern was observed in HL-60, Daudi and Raji cells. 2) Eight of 9 patients with T-ALL had cells with rearranged TCR βgene. But two of 3 patients with B-ALL and three of 5 patients with nonT, nonB-ALL also had cells with rearranged TCR βgene. 3) A 1.3 kb full-length transcript and a 1.0 kb truncated transcript were detected in Jurkat cells by probing with 32P-TCR βcDNA. But some leukemic B cells also expressed an incompleted transcript. 4) TCR βmRNA was detected in six of 8 patients with T-ALL, four of 5 patients with nonT, nonB-ALL and one of 3 patients with B-ALL. But the level of expression was quite differ ent. The dual-rearrangement and the abnormal expression may give us a new clue for researching leukemogenesis.

Clonal immunoglobulin heavy chain and T-cell receptor γ gene rearrangements in primary gastric lymphoma

AIM:To study the diagnostic value of immunoglobulin heavy chain(IgH)and T-cell receptorγ (TCR-γ)gene monoclonal rearrangements in primary gastric lymphoma(PGL).METHODS:A total of 48 patients with suspected PGL at our hospital were prospectively enrolled in this study from January 2009 to December 2011.The patients were divided into three groups(a PGL group,a gastric linitis plastica group,and a benign gastric ulcer group)based on the pathological results(gastric mucosal specimens obtained by endoscopy or surgery)and follow-up.Endoscopic ultrasonography(EUS)and EUSguided biopsy were performed in all the patients.The tissue specimens were used for histopathological examination and for IgH and TCR-γ gene rearrangement polymerase chain reaction analyses.RESULTS:EUS and EUS-guided biopsy were successfully performed in all 48 patients.In the PGL group(n=21),monoclonal IgH gene rearrangements were detected in 14(66.7%)patients.A positive result for each set of primers was found in 12(57.1%),8(38.1%),and 4(19.0%)cases using FR1/JH,FR2/JH,and FR3/JH primers,respectively.Overall,12(75%)patients with mucosal-associated lymphoid tissue lymphoma(n=16)and 2(40%)patients with diffuse large B-cell lymphoma(n=5)were positive for monoclonal IgH gene rearrangements.No patients in the gastric linitis plastica group(n=17)and only one(10%)patient in the benign gastric ulcer group(n=10)were positive for a monoclonal IgH gene rearrangement.No TCRgene monoclonal rearrangements were detected.The sensitivity of monoclonal IgH gene rearrangements was 66.7%for a PGL diagnosis,and the specificity was96.4%.In the PGL group,8(100%)patients with stage IIE PGL(n=8)and 6(46.1%)patients with stage IE PGL(n=13)were positive for monoclonal IgH gene rearrangements.CONCLUSION:IgH gene rearrangements may be associated with PGL staging and may be useful for the diagnosis of PGL and for differentiating between PGL and gastric linitis plastica.

T-CELL RECEPTOR GENE REARRANGEMENT ANALYSIS IN THE PRIMARY CUTANEOUS T-CELL LYMPHOMA

Object: The present paper is to evaluate the significance of T cell receptor (TCR) gene rearrange ments in primary cutaneous T cell lymphomas (PCTCL) as detected by analysis of Southern Blot (SBA) and polymerase chain reaction (PCR). Patients and Methods: Skin specimens and peripheral blood samples were taken from 44 patients with PCTCL, including 30 patients with mycosis fungoides (MF), 2 patients with Sezary's syndrome (SS), and 12 patients with PCTCL other than MF and SS (PNCTCL). 11 patients with a presumptive diagnosis of MF, 23 patients with lymphoproliferative dermatoses including lymphomatoid papulosis (LyP) and 8 patients with benign cutaneous lymphoid infiltrates were simultaneously studied by the amplification of junctional V (variable) J (joining) sequences of the rearranged TCRγ genes by PCR(TCRγPCR) and the analysis of TCRb chain genes by SBA(TCRβSBA) for detection of clonal gene rearrangements (GR). One lymph node specimen of a case with MF IIA was also detected by TCRγ PCR and TCRβSBA. Results: In MF, GR were detected by TCRγPCR and TCRβSBAb in 83.3 85.7% and 66.7% 71.4% of skin specimens of cases IIA IIB and in 57.1% 70.0% and 14.3% 10.0% of those of cases IA IB, respectively. GR were seen in 66.7% 71.4% and 33.3% 43.0.% of blood samples of cases IIA IIB, and 42.9% 40.0% and 0 10.0% of those of cases IA IB, respectively. GR was confirmed by TCRγ PCR and TCRβSBA in one lymph node showing dermato pathic lymphadenopathy of a case with MF IIA. In 11 patients of clinically suspected MF, GR were present in skin specimens of 5 cases (45.4%) and in blood samples of 3 cases ( 27.3% ) by TCRγ PCR. In PNCTCL, GR were found in 9 skin specimens (90.0%) from 10 patients detected by TCRγ PCR and in 6 skin specimens (75.0%) from 8 patients detected by TCRβSBA. GR were also seen in 6 blood samples (72.8%) from 11 patients detected by TCRγ PCR, and in 7 blood samples (70.0%) from 10 patients by TCRβSBA. In SS and LyP, GR were detected by TCRγ PCR and TCRβSBA in each of the two skin specimens of two cases with LyP and in each of the two blood samples of two cases with SS. GR were seen in one skin specimen of one case with SS and one blood sample of one case with LyP detected by TCRγPCR. Conclusions: This study demonstrated that TCRγ PCR is a rapid, more sensitive tool than TCRβSBA, can be used in the analysis of T cell clonality in skin, lymph node and blood samples of patients with PCTCL and indicated that this method forms a useful supplement to other methods for diagnosis of early and suspected MF, confirmation of PNCTCL and determination of extracutaneous involvement of lymph node and blood.

Diagnostic significance of TCR gene clonal rearrangement analysis in early mycosis fungoides

Mycosis fungoides(MF),the most common type of cutaneous T-cell lymphoma,has various unspecific clinical and histological characteristics.Its early diagnosis is challenging.The application of T-cell receptor(TCR) gene clonal rearrangement to the diagnosis of MF has been widely studied.In this study,we used polymerase chain reaction(PCR) to investigate the diagnostic significance of detecting TCR-γ and-β gene clonal rearrangement in the early diagnosis of mycosis fungoides.PCR for TCR-γ and TCR-β gene rearrangement was performed on 19 patients with suspected early MF,6 with typical MF,and 6 with chronic dermatitis.Of the 19 patients with suspected early MF,13 had TCR-γ gene clonal rearrangement,whereas none had TCR-β gene clonal rearrangement.All patients with typical MF had TCR gene clonal rearrangement,in which 4 showed TCR-γ clonal rearrangement,1 showed TCR-β gene clonal rearrangements,and 1 showed both.No patients with chronic dermatitis had TCR gene clonal rearrangement.These results indicate that TCR gene clonal rearrangement analysis is a useful tool in diagnosing early MF.TCR-γ gene is recommended to the routine analysis,whereas TCR-β gene has potential in combination toward intractable cases.

The human application of gene therapy to re-program T-cell specificity using chimeric antigen receptors

The adoptive transfer of T cells is a promising approach to treat cancers. Primary human T cells can be modified using viral and non-viral vectors to promote the specific targeting of cancer cells via the introduction of exogenous T-cell receptors(TCRs) or chimeric antigen receptors(CARs). This gene transfer displays the potential to increase the specificity and potency of the anticancer response while decreasing the systemic adverse effects that arise from conventional treatments that target both cancerous and healthy cells. This review highlights the generation of clinical-grade T cells expressing CARs for immunotherapy, the use of these cells to target B-cell malignancies and, particularly, the first clinical trials deploying the Sleeping Beauty gene transfer system, which engineers T cells to target CD19+ leukemia and non-Hodgkin's lymphoma.

In vivo anti-tumor activity of murine hematopoietic stem cells expressing a p185HER2-specific chimeric T-cell receptor gene

We have confirmed efficient anti-tumor activities of the peripheral lymphocytes transduced with a p185HER2-specific chimeric T-cell receptor gene both in murine and in human in our previous studies. To further test the feasibility of chimeric T-cell receptor in a bone marrow transplantation model, we first, made two murine tumor cell lines: MT901 and MCA-205, to express human p185HER2 by retroviral gene transduction. Murine bone marrow cells were retrovirally transduced to express the chimeric T-cell receptor and gene-modified bone marrow cells were transplanted into lethally irradiated mouse. Six months post transplantation, p185HER2-positive tumor cells:MT-901/HER2 or MCA-205/ HER2 was subcutaneously or intravenously injected to make mouse models simulating primary breast cancer or pulmonary metastasis. The in vivo anti-tumor effects were monitored by the size of the subcutaneous tumor or counting the tumor nodules in the lungs after India ink staining. The size of the subcutaneous tumor was significantly inhibited and the number of pulmonary nodules were significantly decreased in mouse recipients transplanted with chimeric T-cell receptor modified bone marrow cells compared with the control group. Our results suggest the efficient in vivo anti-tumor activities of chimeric T-cell receptor gene modified bone marrow cells.

EXPRESSION OF T CELL RECEPTOR V _α GENE FAMILIES IN INTRATHYROIDAL T CELLS OF CHINESE PATIENTS WITH GRAVES’ DISEASE

Patients with Graves’ disease (GD) have marked lymphocytic infiltration in their thyroid glands We examined the gene for the variable regions of the α chain of the Chinese T cell receptor(V α gene) in intrathyroidal T cells to determine the role of T cells in the pathogenesis of GD and offer potential for the development of immunotherapeutic remedies for GD Methods. We used the reverse transcription and polymerase chain reaction(RT PCR) to amplify complementary DNA(cDNA) for the 18 known families of the V α gene in intrathyroidal T cells from 5 patients with Graves’ disease The findings were compared with the results of peripheral blood T cells in the same patients as well as those in normal subjects Results. We found that marked restriction in the expression of T cell receptor V α genes by T cells from the thyroid tissue of Chinese patients with GD(P<0 001) An average of only 4 6±1 52 of the 18 V α genes were expressed in such samples, as compared with 10 4±2 30V α genes expressed in peripheral blood T cells from the same patients The pattern of expressed V α genes differed from patient to patient with no clear predominance Conclusions. Expression of intrathyroidal T cell receptor V α genes in GD is highly restricted suggesting the primacy of T cells in causing the

用RT-PCR和Genescan分析CML急变期病人TCRVβT细胞的表达和克隆性

目的：了解CML急变期的TCRVβ亚家族T细胞的表达及其克隆性。方法：采用RT－PCR扩增4例CML急变期病人的外周血单个核细胞的TCRVβ24个亚家族的互补决定区3（CDR3），产物进一步经基因扫描分析确定T细胞的克隆性。结果：病人外周血仅表达4～9个Vβ亚家族T细胞，主要为Vβ1，Vβ2，Vβ3，Vβ5，Vβ15和Vβ17；基因扫描分析显示2例CML急粒变的部分产物为寡克隆性，而2例CML急淋变者的产物均为多克隆性。结论：CML急变期外周血仅选择性表达部分Vβ亚家族T细胞；CML急粒变存在克隆性增殖T细胞，这可能是机体对白血病细胞相关抗原的一种直接反应。该方法可用于检测微小残留病变和判断疾病复发。

基于TCR组库分析流程的非小细胞肺癌特征分析

目的·探究非小细胞肺癌(non-small cell lung cancer,NSCLC)免疫相关特征,发掘V-J基因中的肿瘤潜在标志物,为建立T细胞受体(T-cell receptor,TCR)-抗原识别预测模型提供基础。方法·收集704例NSCLC样本,用于构建一套系统的TCR组库分析流程,涵盖从原始数据到质控、过滤、TCR序列的识别和提取等上游分析部分,以及组库克隆分布、克隆分型、V-J基因共享性、互补决定区3(CDR3)分布特征以及克隆追踪等下游分析流程。使用Shannon-Weiner指数、Chao1等指数分析样本克隆分布。根据克隆扩增数目进行克隆分型,以探索不同分型间的差异。选取2例甲状腺乳头状癌(papillary thyroid carcinoma,PTC)样本进行去克隆扩增权重V-J基因共享分析,以探究低频克隆型对V-J基因共享性的影响。最后,通过分析V基因及高频克隆型CDR3分布特征和克隆追踪分析,监测肿瘤免疫前后克隆型频率的变化,寻找潜在的肿瘤标志物。结果·①NSCLC不同组织间克隆分布和克隆分型均存在显著差异,且在不同年龄与性别间存在显著差异。②在V-J基因共享性分析中发现了特定高共享V-J基因,同时在CDR3分布特征分析中存在非正态分布的高克隆V基因与氨基酸高频克隆型。③高频克隆型克隆追踪分析中,观察到NSCLC中高表达或新表达的高频克隆型,提示这些克隆型可作为潜在的肿瘤相关抗原或新抗原结合CDR3参考序列。④通过去克隆扩增权重V-J基因共享分析,发现原本低表达的TRBJ2-5基因表达频率显著增加,提示该基因可能为肿瘤免疫反应的潜在低频关键基因。结论·TRAV21和TRBV6.5基因在NSCLC中高克隆扩增,可作为潜在肿瘤标志物。

CAR-T细胞体内外扩增方法的优化策略

嵌合抗原受体基因修饰T(CAR-T)细胞免疫治疗被认为是最有前景的肿瘤治疗方法之一,效应CAR-T细胞的数量是决定CAR-T细胞疗法治疗效果的关键因素。CAR-T细胞的体外扩增耗时耗力,回输体内后,CAR-T细胞大量耗竭且难以浸润实体瘤,导致能有效抑制实体瘤的CAR-T细胞数量大幅下降。目前,CAR-T细胞的扩增方法在提高扩增特异性和治疗安全性等方面均存在问题,为CAR-T细胞疗法的临床转化造成困难。近年来,新型免疫激动剂及其下游信号的发现为CAR-T细胞扩增方案提供了更多选择,免疫激动剂给药方式的更新迭代进一步提高了其在体内扩增CAR-T细胞的安全性。本文分析了目前扩增CAR-T细胞面临的挑战,系统阐述了近年来在体内外扩增CAR-T细胞的新策略,为CAR-T细胞疗法的疗效和产能优化提供了新思路。

肿瘤精准靶向免疫治疗的关键:T细胞受体抗原筛选技术

过继性T细胞疗法在实体瘤治疗中展现了良好的前景,成为目前肿瘤治疗领域的一大研究热点。其中,TCR-T疗法主要通过T细胞受体(TCR)与抗原肽-主要组织相容性复合体(pMHC)的特异性识别,进而激活过继性T细胞的抗肿瘤免疫反应。因此,全面解析TCR所靶向的抗原信息有助于提高TCR-T疗法在临床应用中的有效性及安全性。然而,高效、高通量的TCR抗原筛选技术的缺乏限制了TCR-T疗法的发展。近年来,随着高通量测序技术、质谱流式细胞技术和计算生物学的快速发展,研究人员开发了多种TCR抗原筛选技术用于解析TCR及其特异性识别的抗原信息。本文从抗原定向筛选、TCR定向筛选以及双向筛选三方面对TCR抗原筛选技术进行归纳总结,系统介绍其优缺点,展望TCR抗原筛选技术领域的发展前景,为未来抗原筛选技术的开发提供了新思路。

Tumor Antigen Specific Activation of Primary Human T-Cells Expressing a Virally Encoded Chimeric T-Cell Receptor Specific for p185HER2

We have developed and tested chimeric T-cell receptors (TCR) specific for p185HER2. In these experiments, retroviral vectors expressing the N29γ or N29ζ receptors were constructed in pRET6. Amphotropic viral producer cells were established in the GALV-based PG13 packaging cell line. Ficoll purified human peripheral blood lymphocytes (PBL) were virally transduced using an optimized protocol incorporating activation with immobilized anti-CD3/anti-CD28 monoclonal anti- bodies, followed by viral infection in the presence of fibronectin fragment CH296. Transduced cells were co-cultured with human tumor cell lines that overexpress (SK-OV-3) or underexpress (MCF7) p185HER2 to assay for antigen specific im- mune responses. Both CM+ and CD8+ T-cells transduced with the N29γ or N29ζ chTCR demonstrated HER2-specific anti- gen responses, as determined by release of Th1 like cytokines, and cellular cytotoxicity assays. Our results support the fea- sibility of adoptive immunotherapy with genetically modified T-cells expressing a chTCR specific for p185HER2.

Rearranged Patterns of IgH and TcRγ Genes in Patients with Acute Lymphoblastic Leukemia

The rearrangement of immunoglobulin heavy chain gene(IgH) and T cell receptor γgene (ToRγ)was studied in 30 patients with acute lymphoblastic leukemia(ALL) by the polymerase chain reaction (PCR). 19 cases was found to have rearrangement of IgH gene,12 of TcRγ. Most of IgH rearrangement was characterized by one or two specific bands while some had more than two. Rearrangement of TcRγgene appeared as one specific band. A slight difference in number, size and lightness of bands was found among the patients. 4 different kinds of rearrangement were observed in the detection of IgH rearrangement in combination with TcRγgene. The rearranged patterns of IgH and TcRγgene as well as the clinical significance were discussed.

基于BCMA突变体构建BCMA CAR-T细胞体外杀伤功能评价模型

目的:为解决野生型B细胞成熟抗原(BCMA)被γ分泌酶切割导致表达不稳定的问题,构建抵抗γ分泌酶切割的BCMA突变体并构建靶细胞,用于评价BCMA CAR-T细胞的杀伤功能。方法:将野生型BCMA的穿膜域替换为人CD8α穿膜域,构建抵抗γ分泌酶切割的BCMA突变体(BCMA-CD8αTM),构建过表达该突变体的U266(U266^(BCMA Mut))、K562(K562^(BCMA Mut))、SKOV3(SKOV3^(BCMA Mut))和CHO(CHO^(BCMA Mut))细胞;构建装载NFAT-EGFP报告基因的BCMA CAR Jurkat细胞(BCMA-CAR-Jurkat-Reporter)与U266^(BCMA Mut)细胞共培养,采用FCM检测该细胞中EGFP表达水平以指示NFAT激活水平,荧光素酶法检测BCMA CAR-T细胞对Luciferase标记的K562^(BCMA Mut)细胞的杀伤作用,实时无标记动态细胞分析技术(RTCA)检测BCMA CAR-T细胞对SKOV3^(BCMA Mut)和CHO^(BCMA Mut)细胞的杀伤作用。结果:应用γ分泌酶抑制剂LY411575抑制γ分泌酶活性,显著增强野生型U266细胞表面BCMA表达水平,平均荧光强度上调10倍以上;但撤除抑制剂后BCMA表达水平逐渐降低(P<0.01);BCMA-CD8αTM突变体可抵抗γ分泌酶的切割作用,在U266细胞表面稳定表达(P>0.05);U266细胞及过表达BCMA-CD8αTM的U266细胞与BCMA-CAR-Jurkat-Reporter细胞共培养后都可激活Reporter系统、增强EGFP表达,但该效应在BCMA-CD8αTM过表达的U266细胞中更显著(P<0.01);BCMA-CD8αTM在BCMA表达阴性的K562、SKOV3和CHO 3种靶细胞中成功过表达,且在LY411575处理下该突变体的表达水平仅有小幅度升高;荧光素酶法检测结果显示,不同效靶比下,BCMA CAR-T细胞均可特异、高效杀伤过表达BCMA-CD8αTM的K562细胞;RTCA结果显示,不同效靶比下,BCMA CAR-T细胞均可有效识别、杀伤过表达BCMACD8αTM的SKOV3和CHO细胞,但同等效靶比下的Mock-T细胞无此效应。结论:本实验构建的BCMA-CD8αTM突变体能够抵抗γ分泌酶的切割,在多种靶细胞表面稳定表达,为评价BCMA CAR-T细胞体外杀伤的有效性和特异性提供多种检测手段。

活动性肺结核患者α/βTCR基因重排及CDR3谱型分析

目的:建立多重PCR方法扩增α/βTCR全长序列,分析活动性肺结核患者病变局部T淋巴细胞α/βTCR基因重排特点及CDR3谱型。方法:分离结核患者肺泡灌洗液中的淋巴细胞,提取RNA后用SMART方法逆转录,运用根据现有文献设计的α和βTCR扩增引物,进行多重PCR扩增以获得其全长序列,构建重组质粒并测序,利用DNAstar及网上TCR资源分析序列。结果:3例患者共获得24个α链序列,13个β链序列。α链以AV1S2(54%)、AV12S3(41%)、AV12S2(5%)为主;β链以BV2(38%)、BV29S1(46%)、BV14(3%)、BV4S2(3%)为主。同一病例及不同病例之间CDR3区呈现多样性,但是标本1、标本3各有一条β链的CDR3氨基酸序列相同:SVGTGTLHQETQY;标本2和标本3的各有2条α链CDR3序列相同:AVRDWAGNMLT;标本2的一个α链和标本3的一个α链的CDR3均有:AV…DNN…RLM序列。结论:建立了TCRα和β链全长序列的多重PCR扩增方法。结核患者病变局部克隆性增殖的TCRα和β链谱型呈限制性取用,克隆增生的T淋巴细胞来自不同的亚群,但是相同的CDR3序列对于识别MTB多肽可能具有特异性。

T细胞性淋巴瘤诊断中TCR基因重排检测的应用

目的探讨T细胞受体(T cell receptors,TCR)基因重排检测对T细胞性淋巴瘤诊断的价值。方法收集T细胞性淋巴瘤30例和淋巴反应性增生组织30例,提取DNA,应用BIOMED-2引物系统中的56条引物进行PCR扩增,核酸分子异源双链凝胶电泳分析结果。结果 30例T细胞性淋巴瘤标本中TCRβ、TCRγ、TCRδ的检出率分别为83.3%(25/30)、93.3%(28/30)、13.3%(4/30),三者联合检测的检出率为96.7%(29/30),30例淋巴反应性增生组织中均未检测出TCR基因重排。结论利用BIOMED-2引物系统检测TCR基因重排可作为T细胞性淋巴瘤的辅助诊断工具。

脐血中TCRVβ亚家族T细胞的分布和克隆性分析

目的 :了解正常脐血中TCRVβ亚家族T细胞的分布和克隆性。 方法 :利用RT -PCR分别扩增 13例正常脐血单个核细胞的TCRVβ 2 4个亚家族基因的CDR3,了解各Vβ亚家族的表达情况。阳性的PCR产物进一步经荧光素标记和基因扫描分析产物的CDR3长度 ,了解T细胞克隆性。 10例正常人外周血和T细胞株Molt- 4及Jurkat作为对照。结果 :正常脐血T细胞仅选择性表达 2 4个Vβ亚家族的 38 78%± 16 2 6 % ,以Vβ 3、5、8、9和 13为多见 ,而正常人外周血T细胞则表达全部 2 4个Vβ亚家族。基因扫描显示正常脐血和正常人外周血的全部PCR产物均呈多峰图象。结论 :正常脐血存在不完全TCRVβ亚家族T细胞 。

正常人外周血和脐血中TCRVβ亚家族sjTRECs的检测情况

目的:检测TCR23个Vβ亚家族sjTRECs在正常人外周血中的存在特点,从而进一步了解正常人胸腺近期各Vβ亚家族初始T细胞的输出情况。方法:采用半巢式PCR对4例胸腺、10例脐血和10例正常人外周血分别在2×105、5×104、1×104和1×103个单个核细胞中的23个Vβ亚家族sjTRECs进行扩增。结果:在细胞数相同的情况下,各Vβ-Dβ1sjTRECs的检出率胸腺细胞最高,其次是脐血,正常人最低。当细胞数为2×105、5×104和1×104时,正常人Vβ2、Vβ4、Vβ7、Vβ11和Vβ19亚家族sjTRECs的检出率以及检出sjTRECs的亚家族数量均显著低于脐血。当细胞数为2×105和5×104时,正常人可检测到绝大多数Vβ亚家族的sjTRECs,随着细胞数的降低,部分Vβ亚家族的sjTRECs则检测不到,而少部分Vβ亚家族的sjTRECs则在1000个细胞时仍能检测到。结论:成功建立了半定量检测23个Vβ亚家族sjTRECs的检测方法;在2×105细胞中约可以检测到80%左右的Vβ亚家族初始T细胞,而在5×104细胞中约有半数的Vβ亚家族初始T细胞可检测到,提示不同Vβ亚家族初始T细胞的出现频率有所差异。

Jurkat细胞TCR基因重排对BV CDR3的影响

目的探讨Jurkat细胞TCRBD2-BJ2基因重排对TCRβ链可变区互补决定区3(BVCDR3)可能产生的影响,为深入研究TCR基因重排奠定实验基础。方法RT-PCR扩增TCRBV26个亚家族CDR3区,结合TCR基因扫描(GeneScan)和基因测序技术,监测Jurkat细胞在增殖传代过程中以及在T细胞激活剂和超抗原SEA等刺激诱导后TCRBVCDR3谱系漂移及长度和序列变化。结果表达TCRBV8家族的单克隆细胞株Jurkat,在增殖传代过程中,以及经刺激诱导48或72h后,未监测到有TCRBV8以外的新的BV亚家族出现,BV8CDR3长度和一级核苷酸序列也未发生变化。结论Jurkat细胞发生的TCR基因重排可能不引起TCRBVCDR3改变,因而对TCRBVCDR3区抗原识别特异性(即抗原特异性漂移)并未产生影响,但并不排除TCR发生改变的可能性。

TCR Vβ2、Vβ5和Vβ17-Dβ1 sjTRECs在正常人胸腺、脐血和外周血中的检测情况

目的建立检测TCR Vβ2、Vβ5和Vβ17-Dβ1 sjTRECs的方法,分析其在胸腺细胞、脐血和正常人外周血T细胞中的存在情况,从而了解近期胸腺输出相应的TCR Vβ亚家族naive T细胞的情况。方法利用半巢式PCR分别扩增3例正常胸腺细胞1、0例脐血和10例正常人外周血单个核细胞DNA中的Vβ2、Vβ5和Vβ17与Dβ1基因片段重排时产生的sjTRECs。结果在正常胸腺细胞、脐血和正常人外周血单个核细胞中均可检测到Vβ2、Vβ5和Vβ17与Dβ1片段形成的sjTRECs,其中胸腺细胞和脐血单个核细胞DNA中3种删除环的检出率均为100%,正常人外周血3种删除环的检出率分别为50%、70%和40%。结论成功地建立检测3种V-βDβ1 sjTRECs的方法,并提供了Vβ2、Vβ5和Vβ17亚家族sjTRECs在胸腺、脐血和外周血中的检测情况。