BACKGROUND The Toll-like receptor (TLR) family is involved in the recognition of and response to microbial infections. These receptors are expressed in leukocytes. TLR stimulation induces the production of proinflammatory cytokines and chemokines. Given that human lung macrophages (LMs) constitute the first line of defense against inhaled pathogens, the objective of this study was to investigate the expression and function of TLR subtypes in this cell population. METHODS Human primary LMs were obtained from patients undergoing surgical resection. The RNA and protein expression levels of TLRs, chemokines, and cytokines were assessed after incubation with subtype-selective agonists. RESULTS In human LMs, the TLR expression level varied from one subtype to another. Stimulation with subtype-selective agonists induced an intense, concentration- and time-dependent increase in the production of chemokines and cytokines. TLR4 stimulation induced the strongest effect, whereas TLR9 stimulation induced a much weaker response. CONCLUSIONS The stimulation of TLRs in human LMs induces intense cytokine and chemokine production, a characteristic of the proinflammatory M1 macrophage phenotype.

中文翻译：

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类似人受体在人类肺巨噬细胞产生细胞因子中的作用。

背景技术Toll样受体（TLR）家族参与微生物感染的识别和响应。这些受体在白细胞中表达。TLR刺激诱导促炎细胞因子和趋化因子的产生。鉴于人类肺巨噬细胞（LMs）是抵抗吸入病原体的第一道防线，因此本研究的目的是研究TLR亚型在此细胞群中的表达和功能。方法人原发性LM是从接受手术切除的患者中获得的。与亚型选择性激动剂孵育后，评估TLR，趋化因子和细胞因子的RNA和蛋白质表达水平。结果在人类LM中，TLR表达水平从一种亚型变化到另一种亚型。用亚型选择性激动剂刺激可引起强烈的，浓度和时间依赖性增加趋化因子和细胞因子的产生。TLR4刺激诱导的作用最强，而TLR9刺激诱导的应答则弱得多。结论刺激人类LM中的TLR会诱导强烈的细胞因子和趋化因子产生，这是促炎性M1巨噬细胞表型的特征。