Dipartimento di Scienze Chimiche, Alimentari, Farmaceutiche e Farmacologiche (DISCAFF), University of Piemonte Orientale Amedeo Avogadro, Via Giovanni Bovio, 6, 28100 Novara, Italy.
Biochem Biophys Res Commun. 2010 Jul 30;398(3):420-5. doi: 10.1016/j.bbrc.2010.06.091. Epub 2010 Jun 25.
The aim of this study was to examine the expression of G protein-coupled receptor (GPR)35 in human invariant natural killer T (iNKT) cells and to determine the functional effects induced by selective activation of this receptor. RT-PCR analysis showed that both human iNKT cells and resting PBMC expressed GPR35; GPR35 protein resulted mostly localized in the plasma membrane, while it internalized in punctate intracellular structures following specific receptor activation (Western blot and immunofluorescence/confocal microscopy analysis). The specific activation of GPR35 by selective receptor agonists [l-kynurenic acid (KYNA)] or 1,4-dihydro-5-(2-propoxyphenyl)-7H-1,2,3-triazolo [4,5-d]pyrimidine-7-one (zaprinast)] functionally correlated with a significant reduction in IL-4 release from alpha-galactosylceramide (alpha-GalCer)-activated human iNKT cells, and this effect resulted mediated by pertussis toxin (PTX)-sensitive Gi/o proteins. In conclusion, our results demonstrate that human iNKT cells express GPR35 functionally active in reducing IL-4 release.
本研究旨在研究 G 蛋白偶联受体 (GPR)35 在人不变自然杀伤 T(iNKT)细胞中的表达，并确定选择性激活该受体所诱导的功能效应。RT-PCR 分析表明，人 iNKT 细胞和静止的 PBMC 均表达 GPR35；GPR35 蛋白主要定位于质膜，而在特异性受体激活后，它会在点状细胞内结构中内化（Western blot 和免疫荧光/共聚焦显微镜分析）。通过选择性受体激动剂 [l-犬尿氨酸 (KYNA)] 或 1,4-二氢-5-(2-丙氧基苯基)-7H-1,2,3-三唑并[4,5-d]嘧啶-7-酮 (zaprinast) 特异性激活 GPR35 与人 α-半乳糖神经酰胺 (α-GalCer) 激活的 iNKT 细胞中 IL-4 释放的显著减少相关，并且这种效应是由百日咳毒素 (PTX) 敏感的 Gi/o 蛋白介导的。总之，我们的结果表明，人 iNKT 细胞表达功能性 GPR35，可减少 IL-4 的释放。
