Anti Mycobacterium tuberculosis IgG antibody mediated complement activation by M tuberculosis

Complement system plays a significant role during the initial stages of mycobacterial infections. The phagocytosis of M. tb by macrophages can be enhanced by opsonization with complement components and is mediated through various receptors. Opsonization with anti-M. tb IgG antibody enhances both classical and alternative complement activation pathways. Anti M. tb IgG antibody enhances the phagocytic ability of the macrophages and alters the complement receptors expression. The secretion of intracellular cytokines by both lymphocytes and monocytes was also altered upon opsonization of M. tb with anti-M. tb IgG antibody.