肝脏天然免疫研究进展

Advances on Innate Immunity of Liver

从肠道至肝脏的血液中富含细菌产物、环境毒素和食物抗原。肝脏依靠强大的天然免疫系统能快速有效地清除外来物质，而不引起有害免疫应答。肝脏富含天然免疫细胞，包括巨噬细胞、自然杀伤细胞、自然杀伤T细胞和γδT细胞。肝细胞表达多种Toll样受体（TLRs），其信号途径的激活在天然免疫应答中发挥重要作用。此外，肝脏通过合成大量可溶性模式识别受体和补体成分在宿主防御微生物入侵和肿瘤转化方面发挥重要作用。肝脏天然免疫系统还积极参与肝脏炎症、损伤和再生的过程。

Blood circulating from intestine to liver is rich in bacterial products, environmental toxins and food antigens. Relying on its strong innate immune system, liver can respond effectively and quickly to eradicate toxic agents without launching harmful immune responses. The liver is abundant in innate imumne cells, such as maerophages, natural killer cells （NK cells）, NKT cells and -/8 T cells. Liver cells express a variety of Toll-like receptors （TLRs）, the activation of TLRs signal pathway plays an important role in the innate immune responses. In addition, the liver also plays a eritieal role in host defenses against invading microorganisms and tumor transformation through the biosynthesis of numerous soluble pathogen recognition receptors and complement eomponents. Finally, the innate immune system is also involved in inflammation, injury and regeneration of liver.