利用T细胞受体变异β基因谱系分析T细胞急性淋巴细胞白血病病人T细胞克隆性

目的:分析T细胞-急性淋巴细胞白血病(T-ALL)病人的T细胞克隆性.方法:利用RT-PCR方法分析6例T-ALL和10例正常人外周血单个核细胞中24个T细胞受体变异β(TCR Vβ)基因的CDR3长度,PCR产物再进一步进行基因扫描和序列分析.结果:3例病人的某些TCR Vβ亚家族T细胞呈单克隆或寡克隆性增殖,主要为Vβ2、3、6、9、21和24.其它3例及正常人均表现为多克隆性增殖T细胞.结论:部分T-ALL来自于TCR Vβ亚家族克隆性增殖T细胞.该方法有助于临床上检测微小残留病变.     

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TCR Vβ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TCR Vβ 24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24个Vβ亚家族的38.78%±16.26%,以Vβ3、5、8、9和13为多见,而正常人外周血T细胞则表达全部24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TCR Vβ亚家族T细胞,所有TCR Vβ亚家族T细胞均呈多克隆性。     

急性单核细胞白血病病人外周血TCR Vβ T细胞克隆性增殖特点

目的:了解急性单核细胞白血病(ANLL-M5亚型)病人TCR Vβ亚家族T细胞的分布及其克隆性。方法:利用RT-PCR分别扩增9例M5病人外周血单个核细胞的TCR Vβ 24个亚家族基因的CDR3,了解病人各Vβ亚家族的利用情况。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。结果:9例病人仅存在1-10个Vβ亚家族T细胞。基因扫描分析显示,8例病人外周血中的某些Vβ亚家族出现寡克隆性T细胞,Vβ2寡克隆T细胞发现于6例病人中,2例分别存在Vβ7或Vβ9克隆性T细胞,2例除Vβ2外,还分别出现Vβ7或Vβ21的寡克隆T细胞。结论:结果提示M5病人外周血Vβ亚家族T细胞的倾斜性分布特点,并存在克隆性增殖的T细胞,这可能是机体T细胞受白血病细胞相关抗原的刺激作用而引起机体产生相应的特异性免疫反应,并以Vβ2的克隆性增殖T细胞为主,提供了明显的趋向性,它可能与M5细胞相关抗原有关。     

T-ALL患者外周血TCRγ/δ T细胞的分布和增殖特点

目的:了解T细胞急性淋巴白血病(T-cell acute lymphocytic leukemia,T-ALL)患者外周血TCR Vγ和Vδ亚家族T细胞的分布和克隆情况。方法:利用RT-PCR扩增9例T-ALL患者和10例正常人外周血单个核细胞中3个TCR Vγ和8个Vδ亚家族基因的互补决定区3(CDR3),了解TCR亚家族Vγ和Vδ亚家族细胞的分布;阳性产物进一步经基因扫描分析CDR3长度,从而了解其克隆性。结果:9例T-ALL患者3个Vγ亚家族的表达率都明显低于正常人Vγ亚家族的表达率(P<0.05);Vδ亚家族中只有Vδ1和Vδ3的表达率低于正常人(P<0.05)。3例T-ALL患者出现克隆性增殖的γ/δT淋巴细胞。结论:T-ALL患者外周血TCR Vγ和部分Vδ亚家族谱系出现限制性表达和克隆性增殖。同时存在克隆性增殖γδ T细胞提示可能为γδ 白血病性T细胞克隆。     

T-ALL及T细胞株相关TCR Vβ基因谱系和克隆性分析

目的了解T细胞-急性淋巴细胞白血病(T-ALL)患者外周血中的T细胞及T细胞株的TCR Vβ基因谱系及其克隆性增殖情况。方法利用RT-PCR方法扩增6个不同的T细胞株和6例初发未治T-ALL病人外周血单个核细胞中24个TCR Vβ基因的互补决定区3(CDR3)，PCR产物进一步经荧光标记和基因扫描分析CDR3长度而确定T细胞的克隆性，部分T细胞株的单克隆PCR产物进一步进行序列分析。结果与正常人外周血表达全部24个Vβ亚家族不同，6例T-ALL病人分别表达5～12个Vβ亚家族。6例病人均存在1个或多个Vβ亚家族的寡克隆或双克隆增殖T细胞，另外，还有一些Vβ亚家族多克隆模式发生改变，呈现寡克隆性增殖的趋势。T细胞株多显示为表达一个Vβ亚家族的单克隆T细胞，不同T细胞株的CDR3长度和序列不尽相同。结论T-ALL患者外周血T细胞的TCR Vβ谱系出现限制性改变，均可检测到克隆性增殖T细胞，尚需进一步鉴定其性质(肿瘤性或抗原特异性增殖)，对于检测微小残留病变和设计抗白血病独特型疫苗均有一定的意义。     

急性单核细胞白血病病人外周血TCR Vα基因谱系和T细胞克隆性增殖特点

目的：了解急性单核细胞白血病（AML-M5）病人TCR Vα29个亚家族的分布及其克隆性。方法: 利用RT-PCR分别扩增8例M5病人外周血单核细胞的TCR Vα29个亚家族基因的CDR3。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。9例健康人作为对照。结果: RT-PCR分析显示正常人表达绝大多数Vα亚家族基因，而8例M5病人外周血仅可以检测到1-10个Vα亚家族基因，出现频率最高的是Vα3（6/8例，75%），其次为Vα12（5/8例，62.5%），有15个Vα亚家族表达缺失（Vα1、4、5、7、9、14-18、20、21、26、28和Vα29）。基因扫描分析显示：8例AML-M5病人中有6例存在克隆性增殖T细胞，其中，以Vα12亚家族出现克隆性增殖T细胞频率（3/5例）最高，有2例仅存在单一的克隆性增殖Vα3亚家族T细胞。正常人外周血各Vα亚家族T细胞主要呈多克隆性。结论: M5病人外周血Vα亚家族T细胞存在明显的选择性选用及克隆性增殖特点，这可能是机体T细胞受M5细胞刺激而引起机体产生相应的特异性免疫反应，同时T细胞TCR Vα亚家族分布及克隆性增殖情况具有个体特异性。     

肿瘤相关TCR Vβ亚家族克隆性增殖T细胞研究进展

利用RT-PCR和基因扫描分析T细胞受体(TCR)Vβ 24个亚家族基因CDR3长度,可确定T细胞的克隆性.对多种实体瘤和白血病等患者T细胞的分析显示病人的TCR Vβ T细胞出现倾斜性分布和克隆性生长的情况.肿瘤相关抗原诱导正常人T细胞同样可出TCR Vβ T细胞亚家族分布的改变和克隆性增殖.这些克隆性增殖T细胞主要是肿瘤相关抗原诱导增殖的,对肿瘤细胞具有特异性杀伤作用,探讨如何利用这种特异性克隆性T细胞作为过继性细胞免疫治疗,清除肿瘤患者微小残留病变,具有重要的意义.     

肿瘤相关TCR Vβ亚家族克隆性增殖T细胞研究进展

利用RT-PCR和基因扫描分析T细胞受体（TCR）Vβ24个亚家族基因CDR3长度，可确定T细胞的克隆性。对多种实体瘤和白血病等患者T细胞的分析显示病人的TCR VβT细胞出现倾斜性分布和克隆生长的情况。肿瘤相关抗原诱导正常人T细胞同样可出TCR VβT细胞亚家族分布的改变和克隆性增殖，这些克隆性增殖T细胞主要是肿瘤相关抗原诱导增殖的，对肿瘤细胞具有特异性杀伤作用，探讨如何利用这种特异性克隆性T细胞作为过继性细胞免疫治疗，清除肿瘤患者微小残留病变，具有重要的意义。     

苯中毒工人外周血TCR Vβ克隆性T细胞利用特点

目的:分析苯中毒工人外周血中克隆性增殖T细胞及其CDR3序列的特点.方法:利用RT-PCR方法扩增11例苯中毒工人外周血单个核细胞中24个TCR Vβ基因的CDR3, 阳性产物进一步经荧光标记和基因扫描分析CDR3长度而了解其克隆性.结果:健康者外周血中可检测到24个Vβ亚家族, 11例苯中毒工人仅检测到2～10个Vβ亚家族.11例苯中毒工人均存在1个或多个Vβ亚家族T细胞出现寡克隆及寡克隆趋势.Vβ2、4、5、6和Vβ21的寡克隆T细胞出现频率较高.结论:苯中毒工人外周血TCR Vβ亚家族T细胞出现倾斜性分布和克隆性增殖, 这可能是机体苯中毒后所引起的特异性免疫反应.     

慢性粒细胞白血病相关的TCR Vβ T细胞的诱导及其限制性和克隆性分析

目的:了解体外诱导CML细胞相关TCRVβ亚家族T细胞克隆性增殖及其杀伤性的情况。方法:采用混合淋巴细胞/白血病细胞培养法(MLTC)体外将CML细胞、K562细胞和bcr-abl多肽与供者外周血单个核细胞混合培养和扩增,利用RT-PCR-基因扫描技术分析培养后T细胞的TCRVβ谱系的限制性利用和克隆性增殖情况,并经LDH法分析诱导增殖T细胞的杀伤性。结果:经bcr-abl多肽、CML细胞和K562细胞诱导扩增1-2周后,供者外周血T细胞表达10-13个Vβ亚家族,在Vβ16和Vβ21出现克隆性增殖T细胞,在Vβ5和Vβ13出现寡克隆生长趋势T细胞。诱导扩增后的T细胞对CML和K562细胞具有特异性杀伤作用。结论:利用CML细胞、K562细胞和bcr-abl多肽可在体外诱导出CML细胞特异性CTL,该CTL可能为优势表达的Vβ亚家族克隆性T细胞。     

利用Fine-tiling aCGH分析TCR基因重排鉴定T细胞白血病克隆

目的:建立基于分析T细胞受体(TCR)基因重排而确定T细胞-急性淋巴细胞白血病(T-ALL)克隆的新方法,为研究T-ALL中涉及TCR基因位点的染色体易位提供基础。方法:提取1例T-ALL患者外周血单个核细胞(PBMC)的总DNA,利用精细定位的寡核苷酸阵列比较基因组杂交(fine-tiling aCGH)分析样本与对照组基因组DNA的差异,了解不同染色体上可能的断裂点和具体的位点,根据所提供的初步结果,从断裂点涉及的基因序列设计特异引物,采用连接介导PCR(LM-PCR)和序列分析等方法去找出与之发生重排的基因序列。并进一步通过RT-PCR检测TCR基因表达。结果:该例T-ALL患者fine-tiling aCGH结果显示14染色体TCRα/δ基因座出现4个断裂点,分别对应TCR Vδ1、Vδ2、Jδ1和Jδ2基因位点。通过LM-PCR、测序及序列分析,该例T-ALL患者的PBMC中TCR基因涉及Vδ1Dδ2Dδ3 Jδ1、Vδ2Dδ3 Jδ2重排。RT-PCR的结果也验证T-ALL表达该TCR基因重排。结论:结果表明,利用fine-tiling aCGH及LM-PCR技术可以找出TCR基因重排,并且该方法是可靠的,也是发现一些涉及TCR位点的融合基因的一条途径。     

Karyotype and T-cell receptor expression in T-lineage acute lymphoblastic leukemia.

The relationship between karyotype and expression of the T-cell receptor (TCR) proteins was examined in 19 patients with T-lineage acute lymphoblastic leukemia (T-ALL). All patients expressed CD3 molecules in the cytoplasm or on the cell membrane. Patients were classified according to TCR expression thus: no TCR expression (TCR-), six cases; cytoplasmic expression of TCR beta chain (cTCRB) only, six cases; membrane expression of TCR alpha and beta chains (mTCRAB), five cases; membrane expression of TCR gamma and delta (mTCRGD), two cases. A chromosomally abnormal clone was detected in 15 cases. The most common site of chromosomal change was at 14q11 (seven cases), the chromosomal band to which TCRA and TCRD have been mapped; as a deletion (two cases); or as a translocation with reciprocal breakpoints in bands containing the TCRG (7p15); TCRB (7q35); or putative oncogenes HOXII (10q24), RBTN2 (11p13) or MYC (8q24) genes. Breakpoints were also seen in 6q (three cases), 9p (two cases), or 11q23 (two cases). The following observations were made: All four chromosomally normal cases lacked TCR expression (TCR-). Breakpoints at 14q11 were found in one of six TCR- cases, four of six cTCRB cases, and two of five mTCRAB cases. Abnormalities of 6q and of 9p were seen only in cases with full TCR expression (mTCRAB or mTCRGD).     

Detection of minimal residual T cell acute lymphoblastic leukemia by flow cytometry.

We have developed a flow cytometric assay for the determination of cellular expression of terminal deoxynucleotidyl transferase (TdT) and applied this to the detection of minimal residual T cell acute lymphoblastic leukemia (T-ALL). The flow cytometric assay for TdT demonstrated requisite specificity: TdT was localized to the nucleus, and was detected in MOLT3 T lymphoblasts, clinical T-ALL samples, and normal bone marrow B lymphoid precursors, but in neither the KG1a myeloid leukemia cell line nor normal myeloid cells. Co-expression of TdT and the pan T cell marker CD5 was used to quantify T lymphoblasts. 0.25 +/- 0.13% of normal adult bone marrow CD5+ cells were TdT+; these may represent early T lymphoid precursors. When admixed with normal bone marrow, CD5+TdT+ leukemic cells could be detected above background levels at an added concentration of 0.035% (95% confidence interval 0.028-0.43%). Long term follow-up of a large number of patients will be required to determine the clinical significance of a minimal burden of leukemic cells.     

T-cell receptor expression in the T-cell malignancies.

Twenty-eight cases with T-cell neoplasms (10 with T-cell acute lymphoblastic leukemia [T-ALL], 10 with T-lymphoblastic lymphoma, and 8 with peripheral T-cell lymphomas) and 2 cases with reactive lymph nodes were immunohistochemically stained with monoclonal antibodies beta F1, delta TCS1, and WT31; beta F1 antibody recognizes the beta-subunit of T-cell receptor (TCR), whereas delta TCS1 and WT31 recognize the delta- and alpha beta-subunits of TCR, respectively. Five cases with T-ALL, four with T-lymphoblastic lymphoma (T-LL), and seven with peripheral T-cell lymphomas were positive for beta F1. None showed positive reactivity for delta TCS1. One case with T-LL and four cases with peripheral T-cell lymphomas were positive for WT31. Of the nine cases positive for beta F1 among T-ALLs and T-LLs, six were also positive for CD1 (OKT6), whereas six of seven positive cases for CD1 were positive for beta F1. The authors therefore suggest that TCR beta is expressed in the immature T-cells just earlier than or around the same stage of differentiation as those expressing CD1. The authors' immuno-electron microscopy study revealed that positive reactivity for beta F1 was localized predominantly in the cytoplasm of the neoplastic cells in the cases with T-ALL, T-LL and peripheral T-cell lymphomas, and in the cytoplasm of the reactive T-cells. However, it was not localized on the surface membrane. In contrast, positive reactivity for WT31 was localized on the surface membrane of the neoplastic and reactive T-cells. Only half of the cases of peripheral T-cell lymphomas showed positive reactivity for WT31. The authors consider that it may not be a very useful antibody for the detection of TCR alpha beta on the T-cell neoplasms using frozen tissue sections.     

Characterization of the CDR3 structure of the Vβ21 T cell clone in patients with P210(BCR-ABL)-positive chronic myeloid leukemia and B-cell acute lymphoblastic leukemia

The clonally expanded T cells identified in most cancer patients that respond to tumor-associated antigen such as P210(BCR-ABL) protein have definite, specific antitumor cytotoxicity. T cell receptor (TCR) Vβ CDR3 repertoire diversity was analyzed in patients with chronic myeloid leukemia (CML) and BCR-ABL(+) B-cell acute lymphoblastic leukemia (B-ALL) by GeneScan. A high frequency of oligoclonal expansion of the TCR Vβ21 subfamily was observed in the peripheral blood of CML and B-ALL patients. These clonally expanded Vβ21 T cells were correlated with the pathophysiologic process of CML. A conserved amino acid motif (SLxxV) was observed within the CDR3 region in only 3 patients with CML. Preferential usage of the Jβ segments was also observed in a minority of patients. The 3-dimensional structures of the CDR3 region containing the same motif or using the same Jβ segment displayed low similarity; on the contrary, the conformation of the CDR3 region containing no conserved motif in some T cell clones was highly similar. In conclusion, our findings indicate a high frequency of TCR Vβ21 subfamily expansion in p210(BCR-ABL)-positive CML and B-ALL patients. The characterization of the CDR3 structure was complex. Regrettably, at this time it was not possible to confirm that the Vβ21 T cell clones were derived from the stimulation of p210(BCR-ABL) protein.