Salamon Pazit, Shefler Irit, Hershko Alon Y, Mekori Yoseph A
Laboratory of Allergy and Clinical Immunology, The Herbert Mast Cell Disorders Center, Meir Medical Center, Kfar Saba, and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Int Arch Allergy Immunol. 2016;171(3-4):203-208. doi: 10.1159/000452625. Epub 2017 Jan 4.
It has recently been reported that mast cells (MC) can be activated to degranulate and release certain cytokines in response to direct physical contact with activated but not resting T cells or their membranes. The MAPK family members ERK and p38 were found to participate. In this work, we further characterize the signaling events involved in this novel pathway of activation.
Human MC were stimulated by activated T cell membranes (T*m). Phosphorylation of kinases was assessed by Western blotting. Protein kinase D (PKD) translocation was visualized by confocal microscopy. Degranulation was assessed by β-hexosaminidase release and cytokine production by ELISA.
Stimulation of human MC by activated T*m resulted in the activation of PKD. PKD inhibition by the specific pharmacological inhibitor Gö6976 resulted in a reduction in the phosphorylation of p38 but not ERK. Gö6976 also inhibited degranulation and cytokine release.
MC stimulation by physical contact with T cells results in PKD activation, leading to the phosphorylation of p38, degranulation and release of cytokines. Understanding the molecular events associated with T cell-induced MC activation might lead to therapeutic approaches for controlling T cell-mediated inflammatory processes in which MC participate.
最近有报道称，肥大细胞（MC）可被激活而脱颗粒，并在与活化而非静止的T细胞或其细胞膜直接物理接触时释放某些细胞因子。发现丝裂原活化蛋白激酶（MAPK）家族成员细胞外信号调节激酶（ERK）和p38参与其中。在本研究中，我们进一步对这一新型激活途径中涉及的信号事件进行了表征。
用人活化T细胞膜（T*m）刺激人MC。通过蛋白质免疫印迹法评估激酶的磷酸化。通过共聚焦显微镜观察蛋白激酶D（PKD）的易位。通过β-己糖胺酶释放评估脱颗粒情况，并通过酶联免疫吸附测定法评估细胞因子产生情况。
活化的T*m刺激人MC导致PKD激活。特异性药理抑制剂Gö6976抑制PKD可导致p38而非ERK的磷酸化减少。Gö6976还抑制脱颗粒和细胞因子释放。
与T细胞物理接触刺激MC导致PKD激活，进而导致p38磷酸化、脱颗粒和细胞因子释放。了解与T细胞诱导的MC激活相关的分子事件可能会带来控制MC参与的T细胞介导的炎症过程的治疗方法。
