The Gram-negative bacterial lipopolysaccharide (LPS)-induced sepsis has emerged as major concern worldwide due to the pressing need to develop its effective treatment strategies which is not available yet. LPS is the major causative agent in the pathogenesis of septic shock. In macrophages, LPS interacts with cell surface TLR4 leading to reactive oxygen species (ROS), TNF-α, IL-1β production, oxidative stress and markedly activated the MAPKs and NF-kB pathway. Post cell isolation, the macrophages were subjected to administration with neutralizing antibodies to TLR4 and TNFR1 either alone or in combination prior to LPS challenge. Subsequently, we performed flow cytometric analysis along with Western blots, reactive oxygen species production, and TNF-α, IL-1β release. Outcomes suggested that the dual blockade of TLR4 and TNFR1 was indeed beneficial in shifting the LPS-induced M1 polarization towards M2. Both TLR4 and TNFR1 exhibited dependency during LPS stimulation. Furthermore, the switch towards the M2 phenotype might be responsible for the decreased levels of TNF-α, IL-1β, NO, and superoxide anion and the simultaneous elevation in the activity level of anti-oxidant enzymes like SOD, CAT (catalase), and GSH content in the isolated peritoneal macrophages. Simultaneous blocking of both TLR4 and TNFR1 also showed reduced expression of NF-kB, JNK, and COX-2 by promoting TNFR2-mediated TNF-α signaling. The increased arginase activity further confirmed the polarization towards M2. Thus it may be inferred that dual blockade of TLR4 and TNFR1 might be an alternative therapeutic approach for regulating of sepsis in future.

由于迫切需要开发其尚不可用的有效治疗策略，革兰氏阴性细菌脂多糖 (LPS) 诱导的败血症已成为全球关注的主要问题。LPS是感染性休克发病机制中的主要病原体。在巨噬细胞中，LPS 与细胞表面 TLR4 相互作用，导致活性氧 (ROS)、TNF-α、IL-1β 产生、氧化应激并显着激活 MAPKs 和 NF-kB 通路。细胞分离后，巨噬细胞在 LPS 攻击前单独或联合施用针对 TLR4 和 TNFR1 的中和抗体。随后，我们进行了流式细胞仪分析以及蛋白质印迹、活性氧物质的产生和 TNF-α、IL-1β 的释放。结果表明，TLR4 和 TNFR1 的双重阻断确实有利于将 LPS 诱导的 M1 极化转向 M2。TLR4 和 TNFR1 在 LPS 刺激期间都表现出依赖性。此外，向 M2 表型的转变可能是导致 TNF-α、IL-1β、NO 和超氧阴离子水平降低以及 SOD、CAT（过氧化氢酶）等抗氧化酶活性水平同时升高的原因，和离体腹腔巨噬细胞中的 GSH 含量。同时阻断 TLR4 和 TNFR1 也显示通过促进 TNFR2 介导的 TNF-α 信号传导降低 NF-kB、JNK 和 COX-2 的表达。精氨酸酶活性的增加进一步证实了向 M2 的极化。