Laboratory of Toxicology, Dipartimento di Scienze Farmacologiche e Biomolecolari (DiSFeB), Università degli Studi di Milano, Via G. Balzaretti 9, 20133, Milan, Italy,
Arch Toxicol. 2014 Feb;88(2):415-24. doi: 10.1007/s00204-013-1144-z. Epub 2013 Oct 18.
We previously demonstrated an age-related decrease in receptor for activated C-kinase (RACK-1) expression and functional deficit in Langerhans cells' responsiveness. This defect specifically involves the translocation of protein kinase C (PKC)-β. The purpose of this study was to investigate the role of RACK-1 and PKC-β in chemical allergen-induced CD86 expression and IL-8 release in the human promyelocytic cell line THP-1 and primary human dendritic cells (DC). Dinitrochlorobenzene, p-phenylenediamine and diethyl maleate were used as contact allergens. The selective cell-permeable inhibitor of PKC-β and the broad PKC inhibitor GF109203X completely prevented chemical allergen- or lipopolysaccharide (LPS)-induced CD86 expression and significantly modulated IL-8 release (50 % reduction). The selective cell-permeable inhibitor of PKC-ε (also known to bind to RACK-1) failed to modulate allergen- or LPS-induced CD86 expression or allergen-induced IL-8 release, while modulating LPS-induced IL-8 release. The use of a RACK-1 pseudosubstrate, which directly activates PKC-β, resulted in dose-related increase in CD86 expression and IL-8 release. Similar results were obtained with human DC, confirming the relevance of results obtained in THP-1 cells. Overall, our findings demonstrate the role of PKC-β and RACK-1 in allergen-induced CD86 expression and IL-8 production, supporting a central role of PKC-β in the initiation of chemical allergen-induced DC activation.
我们之前的研究表明，受体激活 C 激酶（RACK-1）的表达会随着年龄的增长而减少，朗格汉斯细胞的反应性也会出现功能缺陷。这种缺陷特别涉及蛋白激酶 C（PKC）-β的易位。本研究的目的是研究 RACK-1 和 PKC-β 在化学变应原诱导的人早幼粒细胞白血病细胞系 THP-1 和原代人树突状细胞（DC）中 CD86 表达和 IL-8 释放中的作用。二硝基氯苯、对苯二胺和马来酸二乙酯被用作接触变应原。PKC-β 的选择性细胞通透抑制剂和广谱 PKC 抑制剂 GF109203X 完全阻止了化学变应原或脂多糖（LPS）诱导的 CD86 表达，并显著调节了 IL-8 的释放（减少 50%）。PKC-ε 的选择性细胞通透抑制剂（也已知与 RACK-1 结合）不能调节变应原或 LPS 诱导的 CD86 表达或变应原诱导的 IL-8 释放，而调节 LPS 诱导的 IL-8 释放。使用直接激活 PKC-β 的 RACK-1 伪底物导致 CD86 表达和 IL-8 释放呈剂量依赖性增加。在人 DC 中也得到了类似的结果，证实了在 THP-1 细胞中获得的结果的相关性。总的来说，我们的研究结果表明 PKC-β 和 RACK-1 在变应原诱导的 CD86 表达和 IL-8 产生中起作用，支持 PKC-β 在化学变应原诱导的 DC 激活起始中的核心作用。
