Flow Cytometric Measurements of Somatic Cell Mutations in Thorotrast Patients

Exposure to ionizing radiation has long been well-recognized as a risk factor for cancer development. Since ionizing radiation can induce mutations, an accurate way of measuring somatic mutation frequencies could be a useful tool for evaluating cancer risks. In the present study, we have examined in vivo somatic mutation frequencies at the erythrocyte glycophorin A (GPA) and T-cell receptor (TCR) loci in 18 Thorotrast patients who have been continuously irradiated with alpha-particles emitted from the internal deposition of thorium dioxide and who thus have increased risks of certain malignant tumors. When compared with controls, the results showed a significantly higher frequency of mutants at the lymphocyte TCR loci but not at the erythrocyte GPA loci in the Thorotrast patients. The discrepancy between the results of the two assays is discussed.     

The bacterial superantigen and superantigen-like proteins

Summary: The bacterial superantigens are protein toxins that bind to major histocompatibility complex class II and T-cell receptor to stimulate large numbers of T cells. The majority are produced by the Gram-positive organisms Staphylococcus aureus and Streptococcus pyogenes and are the causative agents in toxic shock syndrome, an acute disease caused by the sudden and massive release of T-cell cytokines into the blood stream. The structure and function of the superantigens has revealed a common architecture that is also shared by another group of staphylococcal virulence factors called the superantigen-like proteins (SSL). Together, this family of structurally related molecules highlights how a common pathogenic organism has employed a simple but adaptable protein to generate an armamentarium of potent defense molecules designed to target of the innate and adaptive immune response.     

Protein tyrosine phosphatase conjugated with a novel transdermal delivery peptide,astrotactin 1–derived peptide recombinant protein tyrosine phosphatase (AP-rPTP), alleviates both atopic dermatitis–like and psoriasis-like dermatitis

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Single-cell profiling of peanut-responsive T cells in patients with peanut allergy reveals heterogeneous effector TH2 subsets

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Development of a Wilms�� tumor antigen-specific T-cell receptor for clinical trials: engineered patient��s T cells can eliminate autologous leukemia blasts in NOD/SCID mice

Background

The Wilms’ tumor antigen (WT1) is an attractive target for immunotherapy of leukemia. In the past, we isolated and characterized the specificity and function of a WT1-specific T-cell receptor. The goal of this translational study was to develop a safe and efficient WT1-T-cell receptor retroviral vector for an adoptive immunotherapy trial with engineered T cells.

Design and Methods

We generated a panel of retroviral constructs containing unmodified or codon-optimized WT1-T-cell receptor α and β genes, linked via internal ribosome entry sites or 2A sequences, with or without an additional inter-chain disulfide bond in the T-cell receptor constant domains. These constructs were functionally analyzed in vitro, and the best one was tested in an autologous primary leukemia model in vivo.

Results

We identified a WT1-T-cell receptor construct that showed optimal tetramer staining, antigen-specific cytokine production and killing activity when introduced into primary human T cells. Fresh CD34⁺ cells purified from a patient with leukemia were engrafted into NOD/SCID mice, followed by adoptive immunotherapy with patient’s autologous T cells transduced with the WT1-T-cell receptor. This therapeutic treatment evidently decreased leukemia engraftment in mice and resulted in a substantial improvement of leukemia-free survival.

Conclusions

This is the first report that patient’s T cells, engineered to express the WT1-T-cell receptor, can eliminate autologous leukemia progenitor cells in an in vivo model. This study provides a firm basis for the planned WT1-T-cell receptor gene therapy trial in leukemia patients.     

HepG2细胞诱导下TCR Vα基因的选择性表达研究

目的研究HepG2细胞诱导下T细胞受体(TCR)Vα亚家族基因的选择性表达情况。方法将HepG2细胞与健康人外周血单个核细胞(PBMC)混合培养,利用反转录聚合酶链式反应(RT-PCR)等检测混合培养前后TCR Vα各亚家族基因表达变化。结果混合培养不同时间TCR Vα各亚家族基因表达有一定的变化但并未筛选出针对HepG2细胞特异性表达的TCR Vα亚家族,HepG2和PBMC可能在混合培养96h时相互作用最大。结论在HepG2细胞诱导下,TCR Vα各亚家族基因有一定的选择性但没有明显的特异性表达。     

TCR Vα23-Vβ13 基因修饰T细胞及其特异性细胞毒活性研究

目的: 分析弥漫大B细胞淋巴瘤(DLBCL)抗原特异T细胞受体(TCR) Vα23-Vβ13 基因修饰T细胞后的体外特异性杀伤活性。方法:扩增并克隆已鉴定的DLBCL患者外周血中单克隆增殖T细胞的TCR Vβ13 和TCR Vα23 基因全长序列,构建TCR Vβ13 -IRES-TCR- Vα23 双基因重组质粒,经核转染的方法将其转染正常人T细胞,通过real-time PCR和Western blotting检测TCR Vβ13 和TCR Vα23 这2个外源基因在mRNA和蛋白水平的体外表达情况,并对TCR转基因T细胞进行体外细胞毒性检测。结果:经酶切分析和核酸序列测定证实重组质粒构建正确,转染正常人T细胞后,TCR Vβ13 和TCR Vα23 在mRNA及蛋白水平实现了共表达。转染后3 d,TCR转基因T细胞对DLBCL细胞株Toledo细胞的杀伤活性明显高于非特异细胞株Raji细胞和Molt-4细胞,显示出特异性细胞毒活性。结论:成功构建DLBCL相关抗原特异的TCR Vβ13 -IRES-TCR Vα23 双基因真核表达质粒;TCR基因修饰T细胞可获得特异性细胞毒活性。