The quorum-sensing (QS) signaling-dependent extracellular virulence factors of Pseudomonas aeruginosa can cause infections such as P. aeruginosa keratitis. P. aeruginosa communicates by secreting and sensing small chemical molecules called autoinducers in QS system. The key QS signal molecule, N-3-oxododecanoyl-homoserine lactone (3OC12HSL), can affect the behavior of host cells and initiate immune response. In this report we investigated the influence of 3OC12HSL on human corneal epithelial cells (HCECs) and the mechanisms of 3OC12HSL on activated toll-like receptor 2 (TLR2)-dependent interleukin-8 (IL-8) secretion in HCECs. Cells were cultured under different concentrations of 3OC12HSL. Cell viability was assessed using Crystal violet staining and the cell counting kit-8 assay. We demonstrated the administration of 3OC12HSL decreased HCEC viability and survival in a concentration- and time-dependent manner. At high concentrations, 3OC12HSL rapidly promoted a time-dependent increase in the expressions of TLR2 and TLR4. It was found that the nuclear translocation and expression of nuclear factor-κB (NF-κB) were also increased in response to 3OC12HSL treatment. The significantly elevated expressions of TLR2, TLR4, and NF-κB, encouraged us to further test their mechanisms that cause inflammatory response. Among the inflammatory factors examined (IL-6, IL-8, IL-10, and TNF-α), we found that IL-8 was significantly increased after treatment with 3OC12HSL and its expression was inhibited when TLR2 was specifically blocked or silenced. These results indicated that the QS signaling molecule 3OC12HSL could be recognized by the host innate immune system in HCECs. This recognition then triggered an immune inflammatory response involving the activation of TLR2 and an increase in expression of IL-8. This crosstalk between 3OC12HSL and host immunity in HCECs contributes to the development and progression of P. aeruginosa keratitis.

铜绿假单胞菌的群体感应 (QS) 信号依赖性细胞外毒力因子可引起铜绿假单胞菌角膜炎等感染。铜绿假单胞菌通过分泌和感知 QS 系统中称为自诱导剂的小化学分子进行通信。关键的 QS 信号分子，N-3-oxododecanoyl-homoserine lactone (3OC12HSL)，可以影响宿主细胞的行为并引发免疫反应。在本报告中，我们研究了 3OC12HSL 对人角膜上皮细胞 (HCEC) 的影响以及 3OC12HSL 对 HCEC 中活化的 toll 样受体 2 (TLR2) 依赖性白细胞介素 8 (IL-8) 分泌的机制。在不同浓度的 3OC12HSL 下培养细胞。使用结晶紫染色和细胞计数 kit-8 测定法评估细胞活力。我们证明了 3OC12HSL 的施用以浓度和时间依赖性方式降低了 HCEC 的活力和存活率。在高浓度下，3OC12HSL 迅速促进 TLR2 和 TLR4 表达的时间依赖性增加。发现核转位和核因子-κB (NF-κB) 的表达也响应于 3OC12HSL 处理而增加。TLR2、TLR4 和 NF-κB 的表达显着升高，鼓励我们进一步测试它们引起炎症反应的机制。在检查的炎症因子（IL-6、IL-8、IL-10 和 TNF-α）中，我们发现 IL-8 在用 3OC12HSL 处理后显着增加，并且当 TLR2 被特异性阻断或沉默时其表达受到抑制。这些结果表明QS信号分子3OC12HSL可以被HCECs中的宿主先天免疫系统识别。这种识别随后引发了涉及 TLR2 激活和 IL-8 表达增加的免疫炎症反应。铜绿假单胞菌角膜炎。