全身性エリテマトーデス患者T細胞に発現されるTCRζ鎖の異常に関する研究

系统性红斑狼疮患者T细胞TCRδ链表达异常的研究

• 批准号: 11670455
• 负责人: TAKEUCHI Tsutomu
• 金额: $ 2.43万
• 依托单位: Saitama Medical School
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670455/
• 关键词: signaal transduction; T cell receptor; lupus; CD3 zeta chain; tyrosine phosphorylation; autoimmunity

One of the earliest biochemical events after T cell receptor (TCR) stimulation is the tyrosine phosphorylation of the cellular proteins. Analysis of the tyrosine phosphorylation in T cells have provided us powerful means to investigate the defects in T cell function. To explore the molecular and cellular mechanism of T cell dysfunction observed in SLE, we utilized these systems and examined tyrosine phosphorylation of SLE T cells with or without TCR/CD3 and CD4 stimulation.When we analyze the tyrosine phosphorylation of total cellular lysates prepared from peripheral T cells with or without stimulation, the major bands migrating around 18, 56, 70, and 100KD were always detected in normal T cells. In contrst, tyrosine phosphorylation was diminished in pp18 and pp100 in SLE T, whereas it was normal to high level in 56KD band.Since pp18 seemed to be TCR zeta chain, it was immunoprecipitated from normal and SLE T cells and examined for its tyrosine phosphorylation and protein expression. Tyrosine phosphorylation of the TCR zeta chain and its expression was significantly decreased in more than 60% of the SLE patients. Among those patients, we identified an aberrant form of zeta chain without exon7, or with short exon8, which are presumably generated from alternative splicing.Along with the decreased zeta chain expression in SLE T cells, adaptor proteins and molecular scafold such as linkers for activation of T cells are continuously recruited in the raft fraction. These results may account for the chronic activated status of SLE T cells, through ineffective negative regulation with downregulated zeta chain and subsequent lack of protein tyrosine phosphatase such as SHP-2.

T细胞受体(TCR)刺激后最早的生化事件之一是细胞蛋白的酪氨酸磷酸化。对T细胞酪氨酸磷酸化的分析为我们研究T细胞功能缺陷提供了有力的手段。为了探讨SLE患者T细胞功能障碍的分子和细胞机制，我们利用这些系统检测了TCR/CD3和CD4刺激前后SLE T细胞的酪氨酸磷酸化。当我们分析外周T细胞在刺激或不刺激下制备的总细胞裂解物的酪氨酸磷酸化时，正常T细胞总是检测到18、56、70和100KD左右的主要条带。相反，在SLE T中pp18和PP100的酪氨酸磷酸化水平降低，而在56KD条带中的酪氨酸磷酸化水平正常到高水平。由于pp18似乎是TCR Zeta链，所以从正常和SLE T细胞中免疫沉淀并检测其酪氨酸磷酸化和蛋白表达。在超过60%的SLE患者中，TCR Zeta链的酪氨酸磷酸化及其表达显著降低。在这些患者中，我们发现了一种不含外显子7或具有短外显子8的Zeta链的异常形式，这可能是由选择性剪接产生的。随着SLE T细胞中Zeta链表达的减少，接头蛋白和用于激活T细胞的分子框架(如连接物)不断在RAFT组分中招募。这些结果可能解释了SLE T细胞的慢性激活状态，可能是通过Zeta链下调的无效负调控以及随后缺乏蛋白酪氨酸磷酸酶(如SHP-2)来解释的。

项目成果

Mori S, Maruyama H, Ito I, Tokuhira M, Koide J, Takeuchi T, Itoyama S, Masunaga A, Fukushima M, Suzuki H, and Abe T.: "Diggnosis of measeles viral pneumonia in a patient with Hodgkinls disease by reverse transcription-polymerase chain reaction of serum."I

Mori S、Maruyama H、Ito I、Tokuhira M、Koide J、Takeuchi T、Itoyama S、Masunaga A、Fukushima M、Suzuki H 和 Abe T.：“通过逆转录诊断霍奇金氏病患者的麻疹病毒性肺炎

Fujihara T, Fujita H, Tsubota K, Saito K, Abe T, and Takeuchi T.: "Destruction of lacrimal glands by CD8+aEb7+ T lymphocytes in patients with Sjgrenls syndrome."J Immunol. 163. 2226-35 (1999)

Fujihara T、Fujita H、Tsubota K、Saito K、Abe T 和 Takeuchi T.：“CD8 aEb7 T 淋巴细胞对干燥综合征患者泪腺的破坏。”J 免疫学杂志。

Kanemitsu S,Tsugaka K,Takeuchi T, et al: "Complement conponent 9 deficiency is not a susceptibility factor for SLE."Lupus. 9. 456-457 (2000)

Kanemitsu S、Tsugaka K、Takeuchi T 等人：“补体成分 9 缺乏不是 SLE 的易感因素。”狼疮。

Tsuzaka et al: "Mutations in TCRζ. . ."J Autoimmunity. 11. 381-385 (1998)

Tsuzaka 等人：“TCR 的突变……”J Autoimmunity。11. 381-385 (1998)

Abe T and Takeuchi T.: "Rheumatoid Arthritis and tumor necrosis factor α."J Autoimmunol. (in press,).

Abe T 和 Takeuchi T.：“类风湿性关节炎和肿瘤坏死因子 α。”J Autoimmunol。