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。

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.

Between Scylla and Charybdis:The role of the human immune system in the pathogenesis of hepatitis C

Hepatitis C virus(HCV)frequently elicits only mild immune responses so that it can often establish chronic infection.In this case HCV antigens persist and continue to stimulate the immune system.Antigen persistence then leads to profound changes in the infected host’s immune responsiveness,and eventually contributes to the pathology of chronic hepatitis.This topic highlight summarizes changes associated with chronic hepatitis C concerning innate immunity(interferons,natural killer cells),adaptive immune responses(immunoglobulins,T cells,and mechanisms of immune regulation(regulatory T cells).Our overview clarifies that a strong anti-HCV immune response is frequently associated with acute severe tissue damage.In chronic hepatitis C,however,the effector arms of the immune system either become refractory to activation or take over regulatory functions.Taken together these changes in immunity may lead to persistent liver damage and cirrhosis.Consequently,effector arms of the immune system will not only be considered with respect to antiviral defence but also as pivotal mechanisms of inflammation,necrosis and progression to cirrhosis.Thus,avoiding Scylla-a strong,sustained antiviral immune response with inital tissue damage-takes the infected host to virus-triggered immunopathology,which ultimately leads to cirrhosis and liver cancerthe realm of Charybdis.

Expression of recombination-activating genes and T cell receptor gene recombination in the human T cell leukemia cell line

Background Recent studies have suggested that mature T cells can change their specificity through reexpression of recombination-activating genes （RAG） and RAG-mediated V（D）J recombination. This process is named receptor revision and has been observed in mature peripheral T cells from transgenic mice and human donors. However, whether the receptor revision in mature T cells is a random or orientated process remains poorly understood. Here we used the Jurkat human T cell line, which represents a mature stage of T cell development, as a model to investigate the regulation of T cell receptor （TCR） gene recombination. Methods TCR Dβ-Jβ signal joint T cell receptor excision DNA circles （sjTRECs） were determined by nested and seminested PCR. Double-strand DNA breaks at recombination signal sequences （RSSs） in the TCRVβ chain locus were detected by ligation-mediated-PCR. Further analysis of the complementarity-determining region 3 （CDR3） size of the TCRVβ chain was examined by the TCR GeneScan technique. Results RAG1, RAG2, and three crucial components of the nonhomologous DNA end-joining （NHEJ） pathway were readily detected in Jurkat. Characteristics of junctional diversity of Dβ2-Jβ2 signal joints and ds RSS breaks associated with the Dβ2 5＇ and Dβ 2 3＇ sites were detected in DNA from Jurkat cells. CDR3 size and the gene sequences of the TCRVβ chain did not change during cell proliferation. Conclusions RAG1 and RAG2 and ongoing TCR gene recombination are coexpressed in Jurkat cells, but the ongoing recombination process may not play a role in modification of the TCR repertoire.However, the results suggest that Jurkat could be used as a model for studying the regulation of RAGs and V（D）J recombination and as a ＂special＂ model of the coexistence of TCR gene rearrangements and ＂negative＂ receptor revision.

Profiling the repertoire of T-cell receptor beta-chain variable genes in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection

The profile of T-cell receptor beta-chain variable （TRBV） genes usually skews in subjects with virus infection or cancer. The gene melting spectral pattern （GMSP） can be used to determine the profile of the TRBV gene family. To explore the portrait of the TRBV family in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection （AHI）, peripheral blood mononuclear cells （PBMCs） were separated and further sorted into CD4^＋ and CD8^＋ T-cell subsets. The molecular features of the TRBV complementary determining region 3 （CDR3） motifs were determined using GMSP analysis. When a GMSP profile showed a single peak, the monoclonally expanded TRBV gene was cloned and sequenced. Skewed expansions of multiple TRBV genes were observed among the CD4^＋ and CD8^＋ T-cell subsets and the PBMCs. The frequency of monoclonally expanded TRBV genes in the CD8^＋ T-cell subset was significantly higher than that of the CD4^＋ T-cell subset and the PBMCs. Compared to other members of the TRBV gene family, TRBV11, BV15 and BV20 were predominantly expressed in the repertoire of peripheral blood lymphocytes in recovered AHI subjects. The relatively conserved amino acid motifs of TRBV5.1 and BV20 CDR3 were also detected in the CD4^＋ and CD8^＋ T-cell subsets. These results demonstrate the presence of multiple biased TRBV families in recovered AHI subjects. TRBV11, BV15 and BV20, especially from the CD8＋ T-cell subset, may be relevant to the pathogenesis of subjects with AHh The preferentially selected TRBV5.1 and BV20 with the relatively conserved CDR3 motif may be potential targets for personalized treatments of chronic HBV infection.

Predominant expression of β-chain variable region genes of T-cell receptor in TILs from human renal cell carcinoma

THE repertoire of T-cell antigen receptor(TcR)can be effectively analysed by an approachwith quantitative polymerase chain reaction(qPCR),which allows to characterize the ex-panding T-cell clones by the patterns of restricted usage of TcR V and J region genes.

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.

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.

Study on Cellular Differentiation and Genes Rearrangement of Malignant Lymphoproliferative Disorders

Malignant lymphoproliferative disorders are common diseases characterized by the clonal proliferation of cells derived from the lymphocytes of different developmental stages. The analyses of routine morphology and cytochemistry fail to determine the origin and differentiation stages. The cell differentiation origin of most of malignant lymphoproliferative disorders can be defined by using monoclonal antibodies(McAbs) against the differentiation antigens of lymphocytes, but it is unable to determine the cell origin of a minority of undifferentiated malignancies and also fails to distinguish the malig-

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.

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 disorders

IL-7的诱导表达增强靶向GPC3 CAR-T细胞的增殖及体外抗肿瘤活性

目的:探讨IL-7的诱导表达对靶向磷脂酰肌醇蛋白聚糖3(GPC3)嵌合抗原受体基因修饰T淋巴细胞(CAR-T细胞)的增殖和体外抗肿瘤活性的影响。方法:通过无缝克隆将GPC3 CAR序列片段插入GV400载体的Bam HⅠ/Eco RⅠ位置,构建第二代CAR慢病毒载体GPC3-BBZ及GPC3-BBZ-NFAT-IL-7,以293T细胞包装相应的慢病毒载体后,感染人T细胞制备CAR-T细胞。实验分为未转导T细胞(NT)组、GPC3-BBZ CAR-T细胞组、GPC3-BBZ-NFAT-IL-7 CAR-T细胞组。采用流式细胞术检测各组CAR-T细胞中CAR的表达水平,qPCR法检测经GPC3蛋白激活的CAR-T细胞中IL-7 m RNA的表达水平,细胞计数法检测CAR-T细胞在GPC3抗原刺激下的增殖能力,ELISA检测CAR-T细胞在受到肿瘤细胞刺激后IL-7、IFN-γ和TNF-α的分泌水平。应用实时细胞分析(RTCA)技术检测CAR-T细胞对人肝癌Huh-7细胞的杀伤作用。结果:成功构建慢病毒载体GPC3-BBZ和GPC3-BBZ-NFAT-IL-7,制备出靶向GPC3的CAR-T细胞。经GPC3抗原激活后,GPC3-BBZ-NFAT-IL-7 CAR-T细胞可有效表达IL-7 mRNA(P<0.01),其表现出更强的增殖能力(P<0.05)。与GPC3-BBZ CAR-T细胞相比,GPC3-BBZ-NFAT-IL-7 CAR-T细胞与GPC3阳性靶细胞Huh-7细胞共培养后,分泌更高水平的IL-7、IFN-γ和TNF-α(P<0.01或P<0.001)。RTCA结果显示,GPC3-BBZ-NFAT-IL-7 CAR-T细胞对GPC3阳性Huh-7细胞的杀伤活性显著高于GPC3-BBZ CAR-T细胞(P<0.05)。结论:成功制备可诱导表达IL-7的靶向GPC3的CAR-T细胞,IL-7的诱导表达增强靶向GPC3 CAR-T细胞的免疫活性,在体外展现出较强的肿瘤细胞杀伤能力。

Detection of Minimal Leukemic Cells in Cerebral Spinal Fluid of Children with Acute Lymphoblastic Leukemia Using the Polymerase Chain Reaction Technique

Vδ2Dδ3 rearrangements of T cell receptor (TCR) gene from cerebralspinal fluid (CSF) cells was detected for diagnosis and monitoring of central nervous system leukemia (CNSL) in children with acute lymphoblastic leukemia (ALL) using polymerase chain reaction (PCR) technique. 20 patients were studied and in 12 of them the results of PCR and dot hybridization with clonospecific probes were positive, showing the presence of minimal blast cells in CSF. Our study suggested that the PCR method is an effective tool for clinical diagnosis of CNSL and is much more sensitive than routine CSF examination.

Interactions of Human T Cell Immunoglobin Mucins with Apoptotic Cells

T cell immunoglobulin mucin (TIM) family plays a key role in regulating immune re-sponses.In this study,the interactions of human TIM family with apoptotic cells were evaluated in order to provide a foundation for further study on the roles of human TIM genes in apoptosis.Nine kinds of pEGFP-N1 eukaryotic expression vectors containing different lengths of the three members of human TIM genes for the expression of TIM-EGFP and the vectors for the expression of TIM-Fc fusion pro-teins were constructed.It was found that human TIM proteins could recognize and bind to apoptotic cells directly,but not to viable cells.The interactions of sTIM-1-EGFP,sTIM-3-EGFP and sTIM-4-EGFP with apoptotic cells were blocked by TIM-1-Ig,TIM-3-Ig and TIM-4-Ig fusion proteins respectively.In addition,human TIM proteins mediated the recognition of apoptotic cells and bound to apoptotic cells directly via the IgV domains.In conclusion,the TIM family may play a key role in the regulation of apoptosis.Our data also suggest that human TIM proteins probably serve as novel proteins for the detection of the early cellular apoptosis.

Combination of CRISPR/Cas9 System and CAR-T Cell Therapy:A New Era for Refractory and Relapsed Hematological Malignancies

Chimeric antigen receptor T(CAR-T)cell therapy is the novel treatment strategy for hematological malignancies such as acute lymphoblastic leukemia(ALL),lymphoma and multiple myeloma.However,treatment-related toxicities such as cytokine release syndrome(CRS)and immune effector cell-associated neurotoxicity syndrome(ICANS)have become significant hurdles to CAR-T treatment.Multiple strategies were established to alter the CAR structure on the genomic level to improve efficacy and reduce toxicities.Recently,the innovative gene-editing technology-clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease9(Cas9)system,which particularly exhibits preponderance in knock-in and knockout at specific sites,is widely utilized to manufacture CAR-T products.The application of CRISPR/Cas9 to CAR-T cell therapy has shown promising clinical results with minimal toxicity.In this review,we summarized the past achievements of CRISPR/Cas9 in CAR-T therapy and focused on the potential CAR-T targets.

基于颗粒酶B启动子的磁共振报告基因成像监测CAR-T细胞激活状态

目的利用颗粒酶B(granzyme B,GB)启动子控制铁蛋白(ferritin heavy chain,FTH1)报告基因表达,探讨通过磁共振成像(magnetic resonance imaging,MRI)监测嵌合抗原受体T细胞(chimeric antigen receptor T cells,CAR-T细胞)激活状态的可行性。方法通过Ficoll密度梯度离心法以及流式分选得到细胞毒性T淋巴细胞(cytotoxic T lymphocytes,CTLs)。将GB启动子和FTH1基因连接,连同二唾液酸神经节苷脂(disialoganglioside 2,GD2)嵌合抗原受体(chimeric antigen receptor,CAR)以慢病毒为载体转入CTLs,构建GD2-CAR-T/pGB-FTH1细胞,以GD2-CAR-T/pCMV-FTH1、GD2-CAR-T和T细胞为对照。CytoTox96@非放射性细胞毒性检测各组细胞与人神经母细胞瘤细胞(SK-N-SH)共培养后的杀伤效果,ELISA检测共孵育因子以及GB分泌量,Western blot、普鲁士蓝染色、细胞MRI检测共培养后FTH1基因的表达。结果成功获得CTLs并构建GD2-CAR-T/pGB-FTH1、GD2-CAR-T/pCMV-FTH1、GD2-CAR-T细胞,3组细胞对肿瘤细胞杀伤效果、共孵育因子以及GB分泌量均显著高于T细胞组,GB表达水平在与SK-N-SH细胞共培养后1 d最高,3 d和7 d依次降低。GD2-CAR-T/pGB-FTH1组FTH1相对表达量以及铁含量变化趋势与GB表达一致,MRI信号呈逐渐升高趋势。GD2-CAR-T/pCMV-FTH1组FTH1相对表达量、铁含量及MRI信号在各时间点均无显著差异。GD2-CAR-T和T细胞组无明显FTH1表达及聚铁效应。结论基于GB启动子的MRI报告基因成像可实时反映CAR-T细胞的GB表达水平和肿瘤杀伤作用,为CAR-T治疗提供了一种监测细胞激活状态的可视化手段。

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。

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。

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 。