Toll-like receptor-2 ligand lipomannan from Mycobacterium tuberculosis does not stimulate inflammatory cytokines in dendritic cells

摘要

HIV patients display high incidence of dual infections with Mycobacterium tuberculosis. Some of these patients develop mycobacterial immune restoration disease (IRD) [1]. As Toll-like receptors (TLR) play a critical role in the host immune response to M. tuberculosis [2], Tan et al. [3], recently examined the role of TLR-2-induced cytokine responses in IRD patients. By using a TLR-2 ligand lipomannan from a nonpathogenic Mycobacterium smeg-matis, the authors show that lipomannan induces high levels of tumor necrosis factor (TNF)alpha and interleukin (IL)-12p40 in mycobacterial IRD patients. Based on these results, they conclude that TLR-2-mediated activation of dendritic cells and monocytes/macrophages may contribute to proinflammatory responses and patho-genesis of mycobacterial IRD.