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Analysis of functions of cutaneous mast cells using murine fetal skin-derived cultured mast cells

使用鼠胎儿皮肤来源的培养肥大细胞分析皮肤肥大细胞的功能

基本信息

批准号：
13670874
负责人：
YAMADA Nobuo
金额：
$ 1.98万
依托单位：
University of Yamanashi (Faculty of Medicine)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13670874/
关键词：
Mast cells Innate Immunity Skin Toll-like receptors Cytokines Chemokines CpG motif double-stranded RNA Toll-kike receptors TLR3 TLR9

项目摘要

Toll-like receptors (TLR) mediate innate immune responses by their binding to viral and bacterial products. Recent studies revealed that TLR3 binds to viral double-stranded RNA and that TLR9 binds to CpG motifs, consensus oligodeoxynucleotide sequences specific to bacteria and viruses. This study aimed to determine whether mast cells in skin express TLR3 and TLR9. First we identified mRNA expression of TLR3 and TLR9 in murine fetal skin-derived cultured mast cells (FSMC) that closely resemble cutaneous mast cells. The expression levels of both TLR3 and TLR9 in FSMC were several-fold greater than those in bone marrow-derived cultured mast cells (BMMC) that represent immature (or mucosal) mast cells. Furthermore, FSMC phosphorylated IkBa and secreted cytokines including TNF-a and IL-6 and chemokines including MIP-1a and MIP-2 in response to poly (I:C) (synthetic ligand of TLR3) and CpG oligodeoxynucleotides (but not to randomized oligodeoxynucleotides) to much greater extents than BMMC did. These data assure expression of functional TLR3 and TLR9 on FSMC, and also suggest that their expression may be differentially regulated depending on differentiation of mast cells. Interestingly, unlike stimulation of mast cells through FceRI, stimulation through TLR3 and TLR9 did not cause degranulation and did not induce production of IL-13. Thus skin-associated mast cells express TLR3 and TLR9, recognize pathogen-specific nucleotides, and release proinflammatory cytokines. The absence of IL-13 may be advantageous for the following Th1 responses. Our results suggest novel roles of cutaneous mast cells in innate immunity distinct from their roles in IgE- and Th2-mediated allergic responses.

Toll样受体（TLR）通过与病毒和细菌产物结合来介导先天性免疫应答。最近的研究表明，TLR 3与病毒双链RNA结合，TLR 9与CpG基序结合，CpG基序是细菌和病毒特异性的共有寡核苷酸序列。本研究旨在确定皮肤中肥大细胞是否表达TLR 3和TLR 9。首先，我们确定了TLR 3和TLR 9的mRNA表达在小鼠胎儿皮肤来源的培养肥大细胞（FSMC），非常类似于皮肤肥大细胞。FSMC中TLR 3和TLR 9的表达水平是骨髓来源的培养肥大细胞（BMMC）中的表达水平的数倍，BMMC代表未成熟（或粘膜）肥大细胞。此外，FSMC磷酸化IkBa和分泌的细胞因子包括TNF-α和IL-6和趋化因子包括MIP-1a和MIP-2响应于poly（I：C）（TLR 3的合成配体）和CpG寡脱氧核苷酸（但不响应于随机寡脱氧核苷酸）的程度比BMMC大得多。这些数据确保了FSMC上功能性TLR 3和TLR 9的表达，并且还表明它们的表达可能根据肥大细胞的分化而受到差异调节。有趣的是，与通过FceRI刺激肥大细胞不同，通过TLR 3和TLR 9的刺激不引起脱粒并且不诱导IL-13的产生。因此，皮肤相关肥大细胞表达TLR 3和TLR 9，识别病原体特异性核苷酸，并释放促炎细胞因子。IL-13的缺乏可能有利于以下Th 1应答。我们的研究结果表明，皮肤肥大细胞在先天免疫中的新作用，不同于它们在IgE和Th 2介导的过敏反应中的作用。