Decreased expression of TCRζ and signal transduction due to the aberrantexpression of the TCR mRNA in SLE patient T cells

我们最近报道了系统性红斑狼疮（SLE）患者T细胞受体α链（α链）的表达显著降低或缺失，这是由于α链mRNA剪接变异体具有可变剪接的短3 'UTR（α链mRNA/as-3' UTR）或缺失外显子7（α链mRNA/ex 7-）。本研究利用逆转录病毒系统研究了TCR/CD 3包括CD 4的表达。结果表明，由于SLE患者TCR/CD 3复合物（包括CD 4+）的不稳定性，TCR/CD 3复合物的表达和CD 4 + mRNA/ex 7-产生的IL-2显著降低。为了检测这些TCR/CD 3复合物（包括CD 4+）减少或缺失的T细胞是否表现出提示SLE的差异转录模式，我们通过DNA微阵列分析比较了基因表达谱。结果表明，syndecan-1（Sdc-1）、颗粒酶A、硒结合蛋白和溶质载体家族4的基因在携带有mRNA剪接变异体的转染子中普遍上调。另一方面，几种细胞因子（IL-2）的那些 ...更多信息 、IL-15、IL-18、TGF- β）水平降低。通过这些观察，鉴定T细胞中的这些应答基因伴随着TCR/CD 3复合物（包括CD 4）的下调，可能有助于更好地理解T细胞功能障碍和SLE发病机制的机制。我们采用Western blot（WB）检测了Sdc家族（Sdc-1至Sdc-4）在SLE T细胞中的表达。结果，在SLE患者T细胞和健康的正常对照之间，没有观察到Sdc 1、Sdc 2和Sdc 3的表达模式的差异。然而，35-和40-kD的蛋白带检测与抗Sdc 4抗体中的10个11 SLE患者T细胞的丢失。用抗-β-CD抗体WB检测10例SLE患者的β-CD也均缺失.这种Sdc 4相关的35 kD蛋白在抗HS抗体处理后被吸收。流式细胞仪分析显示，9/12例SLE患者细胞表面HS和Sdc 4减少或缺失。有趣的是，已报道将N-乙酰葡糖胺（GlcNAc）转移至Sdc家族核心蛋白的共同接头四糖的外生鱼藤素样2（EXTL 2）酶的产生在这9个SLE患者T细胞中显著减少或缺失。少

We recently reported that expression of the T-cell receptor ζ chain (ζ) was significantly decreased or absent in systemic lupus erythematosus (SLE) patients due to the ζ mRNA splice variants with alternatively spliced short 3'UTR (ζ mRNA/as-3'UTR) or with deletion of exon7 (ζ mRNA/ex7-). Here we investigated the expression of TCR/CD3 including ζ by using retrovirus systems. As a result, the expression of TCR/CD3 including ζ and IL-2 production from ζ mRNA/ex7- was significantly decreased due to the instability of ζ mRNA/ex7-.To examine whether these T cells with decreased or absent of TCR/CD3 complex including ζ exhibit differential transcription patterns that are indicative of SLE, we compared the gene expression profile by DNA microarray analysis. As a result, genes of syndecan-1 (Sdc-1), granzyme A, selenium binding protein, and solute carrier family 4 were up-regulated commonly in the transfectant with ζ mRNA splice variant froms. On the other hand, those of several cytokines (IL-2 … More , IL-15, IL-18, TGF- β) and were decreased. From these observations, identification of these responsive genes in T-cells accompanied by the down-regulation of TCR/CD3 complex including ζ may help to better understand the mechanism underlying T-cell dysfunction and pathogenesis of SLE.We investigated the expression of Sdc families (Sdc-1 through Sdc-4) in SLE T cells by using Western blot (WB). As a result, there observed no differences in the expression patterns of Sdc1, Sdc2, and Sdc3 between in SLE patient T cells and in healthy normal controls. However, the 35- and 40-kD protein bands detected with anti-Sdc4 antibody were missing in 10 out of 11 SLE patient T cells. Ζ was also missing in these 10 SLE patients by WB using anti-ζ antibody. This Sdc4-related 35-kD protein was absorbed after the treatment of anti-HS antibody. In FACS analysis, cell surface HS and Sdc4 was decreased or missing in 9 out 12 SLE patients. Interestingly, the production of exostosin-like 2 (EXTL2) enzyme, which has been reported to transfer N-acetylglucosamine (GlcNAc) to the common linker tetrasaccharide of a core protein of Sdc families, was significantly reduced or missing in these 9 SLE patient T cells. Less