Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, 92 APC Road, Calcutta, 700009, West Bengal, India.
Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, 92 APC Road, Calcutta, 700009, West Bengal, India.
Microb Pathog. 2024 Feb;187:106518. doi: 10.1016/j.micpath.2023.106518. Epub 2023 Dec 30.
In vivo studies identifying a role of TLR2 in septic arthritis models are lacking. TNF-α played as the most important proinflammatory cytokine, and connected directly to the pathogenesis of bacterial arthritis. IL-1β is another central mediator cytokine in arthritis. It is therefore reasonable to question the role of neutralization of endogenous TNF-α and IL-1β along with TLR2 and associated downstream signaling as crucial mediators in the S. aureus -induced inflammatory arthritis. In reaction to an injury or a pathogen encounter, innate immune cells serve as the initial line of defense. TLR2 mediated entry of S. aureus into macrophage cells initiates an array of inflammatory cascades. After macrophage cell gets activated at the site inflammation, they generate elevated number of cytokines which includes TNF-α, IL-1β. This cytokines signals through STAT1/STAT3 mediated pathways. Thus, aim of this study was to discover how This bone damage could be altered by altering the STAT/STAT3/SOCS3 ratio by blocking TLR2, a particular S. aureus binding site, in conjunction with the use of IL-1 and TNF- antibodies for neutralizing endogenous IL-1β and TNF-α. Additionally, the role of local macrophages in therapy of arthritis was investigated in synovial and Splenic tissue. To comprehend the inflammatory milieu within the system, ROS and other antioxidant enzymes, along with the expression of mTOR in macrophage cells, were also taken into consideration. The detrimental impact of bacterial burden on synovial joints was reduced by simultaneously inhibiting TLR2, TNF-α, and IL-1β. Lowered IFN-γ decreases its sensitivity to STAT1 and lowered IL-6 reduces STAT3 expressions. Whereas, elevated IL-10 enhances SOSC3 expression, which thereby able to limits STAT1/STAT3 inter-conversion. As a result, NF-κB activity was downregulated.
体内研究表明 TLR2 在脓毒性关节炎模型中发挥作用。TNF-α 作为最重要的促炎细胞因子,直接与细菌性关节炎的发病机制有关。IL-1β 是关节炎中另一种重要的中介细胞因子。因此,有理由质疑中和内源性 TNF-α 和 IL-1β 以及 TLR2 及其相关下游信号转导作为金黄色葡萄球菌诱导的炎症性关节炎中的关键介质的作用。在对损伤或病原体的反应中,先天免疫细胞作为第一道防线。TLR2 介导金黄色葡萄球菌进入巨噬细胞,引发一系列炎症级联反应。在炎症部位,巨噬细胞被激活后,会产生大量细胞因子,包括 TNF-α、IL-1β。这些细胞因子通过 STAT1/STAT3 介导的途径发出信号。因此,本研究的目的是通过阻断 TLR2(金黄色葡萄球菌的一个特定结合位点),结合使用 IL-1 和 TNF-α 抗体中和内源性 IL-1β 和 TNF-α,来发现这种骨损伤如何通过改变 STAT/STAT3/SOCS3 比值来改变。此外,还研究了滑膜和脾组织中局部巨噬细胞在关节炎治疗中的作用。为了了解系统中的炎症环境,还考虑了 ROS 和其他抗氧化酶以及巨噬细胞中 mTOR 的表达。同时抑制 TLR2、TNF-α 和 IL-1β 可减轻细菌负荷对滑膜关节的损害。降低 IFN-γ 会降低其对 STAT1 的敏感性,降低 IL-6 会降低 STAT3 的表达。而升高的 IL-10 会增强 SOSC3 的表达,从而能够限制 STAT1/STAT3 的相互转化。结果,NF-κB 活性被下调。