Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, South Korea.
Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, South Korea.
Biomaterials. 2017 May;126:49-60. doi: 10.1016/j.biomaterials.2017.02.023. Epub 2017 Feb 20.
Negative regulation of Toll-like receptor-4 (TLR4) is anticipated to control the pathogen-induced exaggerated immune response. However, effective TLR4 antagonists with scarce off-target effects are yet to be developed. To fill this void, we sought to design small peptide-inhibitors of the TLR4/MD2-LPS interaction. Here we report novel TLR4-antagonistic peptides (TAP), identified through phage display, endowed with the LPS-induced proinflammation inhibition, and confirmed in mice. TAPs-attributed TLR4-antagonism were initially evaluated through NF-κB inhibition in HEK-blue hTLR4 and RAW264.7 cells, and further reinforced by the downregulation of MAPKs (mitogen-activated protein kinases), NF-κB, interleukin 6, and suppression of the oxidative-stress products and iNOS in macrophages and human peripheral blood mononuclear cells (hPBMCs). Among these, TAP2 specifically halted the TLR4, but not other TLRs signaling, which was further confirmed by the biophysical kinetic assay. Finally, TAP2 diminished LPS-elicited systemic cytokine response in vivo, suggesting that TAPs, specifically TAP2, have the potential to treat TLR4-mediated immune ailments.
负向调控 Toll 样受体 4（TLR4）有望控制病原体诱导的过度免疫反应。然而，具有较少脱靶效应的有效 TLR4 拮抗剂尚未开发出来。为了填补这一空白，我们试图设计 TLR4/MD2-LPS 相互作用的小肽抑制剂。在这里，我们报告了通过噬菌体展示鉴定的新型 TLR4 拮抗肽（TAP），它们具有抑制 LPS 诱导的促炎作用，并在小鼠中得到了证实。TAP 赋予的 TLR4 拮抗作用最初通过 HEK-blue hTLR4 和 RAW264.7 细胞中的 NF-κB 抑制进行评估，并通过 MAPKs（丝裂原活化蛋白激酶）、NF-κB、白细胞介素 6 的下调以及巨噬细胞和人外周血单核细胞（hPBMCs）中氧化应激产物和 iNOS 的抑制得到进一步加强。其中，TAP2 特异性阻断 TLR4 信号，而不是其他 TLR 信号，这通过生物物理动力学测定进一步得到证实。最后，TAP2 减轻了 LPS 诱导的体内细胞因子反应，表明 TAPs，特别是 TAP2，具有治疗 TLR4 介导的免疫疾病的潜力。
