2007 Fiscal Year Final Research Report Summary
Decreased expression of TCRζ and signal transduction due to the aberrantexpression of the TCR mRNA in SLE patient T cells
| Project/Area Number |
16590993
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
膠原病・アレルギー・感染症内科学
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| Research Institution | Saitama Medical University |
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Principal Investigator |
TSUZAKA Kensei Saitama Medical University, Medicine, Assistant Prof (00245490)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEUCHI Tsutomu Saitama Medical School, Medicine, Prof. (50179610)
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| Project Period (FY) |
2004 – 2007
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| Keywords | Systemic lupus erythematosus / TCR ζ / mRNA 3'UTR / alternative splicing / syndecan / EXTL2 |
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| Research Abstract |
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
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, 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
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Research Products
(18 results)
