Host responses against mycobacterial infection result in protection and granulomatous inflammation. Mycobacterial and host factors participate in the process. Mycobacteria are rich in lipids that may be involved in the pathogenesis. Host responses against the infection include both cell-mediated immune responses (host defense) and delayed-type hypersensitivity (expression of lesions) . A surface glycolipid of tubercle bacilli acts as both nonspecific inflammatory stimulus and specific T cell-dependent immunogen. Hosts produce chemokines, proinflammatory and immunoregulatory cytokines in response to glycolipids. The event leads to the recruitment of mononuclear cells, angiogenesis, and apoptosis. Mycobacterial glycolipid is a pleiotropic molecule, which induces pathogenesis and protective responses in the host. The pathogenesis of mycobacterial disease is a multistep process, involving a complex interaction between a range of bacterial and host factors.
