Extracellular Hsp70 (eHsp70) can activate immune cells via Toll-like receptors (TLR) 2 and 4, and induce cytokine synthesis. The aim of this study was to explore inflammation-associated effects of eHsp70 alone and in combination with cigarette smoke extract (CSE) in primary bronchial epithelial cells.

We assessed IL-6 and IL-8 concentrations, TLR2, TLR4 and Hsp70 mRNA expressions, and mitogen-activated protein kinases (MAPKs) activation induced by recombinant human (rh) Hsp70, CSE or their combinations in normal human bronchial epithelial cells (NHBE) obtained commercially, and primary bronchial epithelial cells isolated from non-COPD lung donors (PBEC) or COPD patients (PBEC COPD).

Baseline levels of IL-6 and IL-8 were significantly higher in PBEC COPD than in non-COPD PBECs. Upon rhHsp70 stimulation, IL-6 and IL-8 were significantly increased, with the strongest response in COPD-derived PBECs. CSE alone elevated cytokine secretion in all examined cells. rhHsp70 and CSE had antagonistic interactions on IL-8 release in PBECs from COPD patients, while the addition of rhHsp70 further increased CSE-induced IL-6 secretion in NHBE cells. rhHsp70 and CSE alone decreased TLR2 and TLR4 mRNA expression in COPD-derived PBECs. In non-COPD PBECs, combined treatments decreased only TLR2 mRNA expression. Hsp70 mRNA expression, as indicator of intracellular Hsp70, which may have anti-inflammatory effects, was reduced in COPD-derived cells upon exposure to CSE and rhHsp70 alone, but not with their combinations. Contrary to this, in PBECs from lung donors only combined treatments supressed Hsp70 gene expression. CSE activated JNK and p38 MAPKs, while rhHsp70 increased activation of c-Jun kinase in NHBE cells.

Collectively, both eHsp70 and CSE induce pro-inflammatory responses in PBECs from non-COPD as well as COPD donors, but in combination antagonistic effects were observed in COPD-derived cells. These effects may be related to the regulation of TLR2/4 and might lead to modulation of inflammation with possible deleterious consequences for COPD patients.

细胞外Hsp70（eHsp70）可以通过Toll样受体（TLR）2和4激活免疫细胞，并诱导细胞因子合成。这项研究的目的是探讨eHsp70单独和与香烟烟雾提取物（CSE）联合在原发性支气管上皮细胞中的炎症相关作用。

我们评估了重组人（rh）Hsp70，CSE或其组合在正常人支气管上皮细胞（NHBE）中诱导的IL-6和IL-8浓度，TLR2，TLR4和Hsp70 mRNA表达以及促分裂原激活的蛋白激酶（MAPK）活化）并从非COPD肺供体（PBEC）或COPD患者（PBEC COPD）中分离出原代支气管上皮细胞。

PBEC COPD中的IL-6和IL-8基线水平显着高于非COPD PBEC。在rhHsp70刺激后，IL-6和IL-8显着增加，在COPD衍生的PBEC中反应最强。单独的CSE可以提高所有检查过的细胞中细胞因子的分泌。rhHsp70和CSE对COPD患者的PBEC中IL-8释放具有拮抗作用，而rhHsp70的添加进一步增加了CSE诱导的NHBE细胞中IL-6的分泌。仅rhHsp70和CSE降低了COPD来源的PBEC中TLR2和TLR4 mRNA的表达。在非COPD PBEC中，联合治疗仅降低TLR2 mRNA表达。单独暴露于CSE和rhHsp70的COPD衍生细胞中，Hsp70 mRNA表达作为细胞内Hsp70的指示剂（可能具有抗炎作用）降低，但不与它们的组合暴露。与此相反，在来自肺供体的PBEC中，仅联合治疗抑制了Hsp70基因的表达。CSE激活了JNK和p38 MAPK，而rhHsp70增加了NHBE细胞中c-Jun激酶的激活。

总体上，eHsp70和CSE均可诱导来自非COPD和COPD供体的PBEC中的促炎反应，但在源自COPD的细胞中观察到了拮抗作用。这些作用可能与TLR2 / 4的调节有关，并可能导致炎症调节，对COPD患者可能造成有害后果。