Toll样受体在结核病免疫应答中的作用

The role of Toll-like receptors in immune response to tuberculosis

结核病(Tuberculosis)主要是由结核分枝杆菌(Mycobacterium tuberculosis,MTB)引起的重大传染性疾病。Toll样受体(Toll-like receptors,TLRs)在宿主的抗结核免疫应答中发挥重要作用。研究表明,TLR1、2、4、6和9与宿主抗MTB感染有关,其中TLR2的作用更为突出。免疫应答的早期阶段,TLR2介导了巨噬细胞的活化,通过产生具有直接杀伤效应的分子或者诱导宿主细胞的凋亡抑制MTB的增殖。然而TLR2介导的信号通路也可通过降低MHC-Ⅱ分子的表达来削弱抗原递呈的能力,促进MTB在宿主内的存活。近几年临床研究发现TLRs多态性位点与结核病易感有关也从侧面证实了TLRs在抗MTB感染中发挥重要作用。

Tuberculosis,caused by the bacterium mycobacterium tuberculosis（MTB）,is one of the most highly infectious diseases.Toll-like receptors（TLRs） play important roles in activating immune response against tuberculosis.Studies indicate that anti-tuberculosis immune response is mediated by TLR1,TLR2,TLR4,TLR6,and TLR9,especially by TLR2.In the early stage of the immune response,TLR2 induces macrophage activation,anti-bacterial molecule production,and cell apoptosis that leads to the suppression of MTB proliferation.However,TLR2 signaling from MTB is also reported to facilitate MTB survival through decrease in MHC-II expression or antigen-processing activity.Clinic studies reveal associations between TB and single nucleotide polymorphisms（SNPs） with in TLRs gene,suggesting a crucial role of TLRs in the host defense against MTB.