Manivannan S, Rao Narayan V, Ramanathan V D
Department of Clinical Pathology, Tuberculosis Research Centre (ICMR), Chetpet, Chennai 600 031, India.
Indian J Exp Biol. 2012 Aug;50(8):542-50.
Mycobacterium tuberculosis-specific antibodies possess immunomodulatory effects during tuberculosis infection. Prior sensitization to environmental mycobacteria is known to suppress immune responses against BCG and M. tuberculosis. Mycobacteria-induced antibodies can influence events such as complement activation and phagocytosis during infectious process. In the present study role of anti-M. tuberculosis IgG (anti-M. tb IgG) antibody during interaction between M. tuberculosis and human macrophages mediated through complement has been examined in vitro. Anti-M. tb IgG antibody significantly enhanced complement activation by M. tuberculosis. Phagocytosis of M. tuberculosis by macrophages increased significantly in the presence of complement and/or antibody. Moreover, antibody enhanced phagocytosis in the presence of complement. Addition of antibody alone or in combination with complement also augmented intracellular viability of bacilli within macrophages. Results of this study showed that anti-mycobacterial antibody enhances complement activation and anti-M. tb IgG antibody probably modulates effects of complement during early stages of tuberculosis infection.
结核分枝杆菌特异性抗体在结核感染过程中具有免疫调节作用。已知先前对环境分枝杆菌的致敏会抑制针对卡介苗和结核分枝杆菌的免疫反应。分枝杆菌诱导的抗体可在感染过程中影响补体激活和吞噬作用等事件。在本研究中，已在体外检测了抗结核分枝杆菌IgG（抗结核分枝杆菌IgG）抗体在结核分枝杆菌与人巨噬细胞之间通过补体介导的相互作用过程中的作用。抗结核分枝杆菌IgG抗体显著增强了结核分枝杆菌的补体激活。在补体和/或抗体存在的情况下，巨噬细胞对结核分枝杆菌的吞噬作用显著增加。此外，抗体在补体存在的情况下增强了吞噬作用。单独添加抗体或与补体联合添加也增强了巨噬细胞内杆菌的细胞内存活率。本研究结果表明，抗分枝杆菌抗体增强补体激活，抗结核分枝杆菌IgG抗体可能在结核感染早期调节补体的作用。
