College of Pharmacy, Yeungnam University, Gyeongsan, Korea.
YU-ECI Research Center for Medical Science, Yeungnam University, Gyeongsan, Korea.
Allergy. 2018 Feb;73(2):361-368. doi: 10.1111/all.13296. Epub 2017 Oct 17.
In mast cells, induction of HSP70 expression during antigen stimulation has not been reported.
Mouse bone marrow-derived mast cells (BMMC) were stimulated with IgE/Ag or HSP70. Induction of HSP70 expression and signaling protein phosphorylation were evaluated by immunoblotting.
HSP70 expression is induced in BMMC at an early stage of IgE/Ag-dependent stimulation, some of which is released from the cells in a granule-associated form. Induction of HSP70 expression was also observed with an IgE/Ag-stimulated human basophilic cell line, indicating that the phenomenon is not restricted to mouse BMMC. The induction of HSP70 expression, and its release, followed a similar time course to that of degranulation. Released HSP70 seems to be responsible for degranulation and production of eicosanoids, at least in part, because a neutralizing anti-HSP70 antibody mitigated these activities and because exogenous HSP70 not only induced immediate degranulation followed by autocrine HSP70 expression but also enhanced degranulation in IgE/Ag-stimulated BMMC. Extracellular HSP70 was found to induce phosphorylation of linker for activation of T cells (LAT) and a series of downstream signaling molecules in BMMC. We further found that Fyn, Lyn, and spleen tyrosine kinase (Syk), which are known to concern LAT phosphorylation in IgE/Ag-stimulated BMMC, were not phosphorylated in HSP70-stimulated BMMC, whereas lymphocyte-specific protein tyrosine kinase (Lck) was phosphorylated.
FcεRI stimulation in BMMC and basophils induces HSP70 expression and its release. Extracellular HSP70 induces degranulation and mediator release via phosphorylation of LAT.
在肥大细胞中，抗原刺激诱导 HSP70 表达尚未见报道。
用 IgE/Ag 或 HSP70 刺激鼠骨髓来源的肥大细胞（BMMC）。通过免疫印迹评估 HSP70 表达和信号蛋白磷酸化的诱导。
在 IgE/Ag 依赖性刺激的早期，BMMC 中诱导 HSP70 表达，其中一些以颗粒相关形式从细胞中释放。用 IgE/Ag 刺激的人类嗜碱性细胞系也观察到 HSP70 表达的诱导，表明该现象不仅限于鼠 BMMC。HSP70 表达的诱导及其释放与脱颗粒的时间进程相似。释放的 HSP70 似乎至少部分负责脱颗粒和产生类花生酸，因为中和抗 HSP70 抗体减轻了这些活性，并且因为外源性 HSP70 不仅诱导即刻脱颗粒，随后自分泌 HSP70 表达，而且增强 IgE/Ag 刺激的 BMMC 中的脱颗粒。发现细胞外 HSP70 诱导 BMMC 中链接激活 T 细胞（LAT）和一系列下游信号分子的磷酸化。我们进一步发现，在 IgE/Ag 刺激的 BMMC 中，已知与 LAT 磷酸化有关的 Fyn、Lyn 和脾酪氨酸激酶（Syk）在 HSP70 刺激的 BMMC 中未发生磷酸化，而淋巴细胞特异性蛋白酪氨酸激酶（Lck）发生磷酸化。
FcεRI 在 BMMC 和嗜碱性粒细胞中的刺激诱导 HSP70 表达及其释放。细胞外 HSP70 通过 LAT 的磷酸化诱导脱颗粒和介质释放。
