Chemokines and tuberculosis.

Mycobacterium tuberculosis is a respiratory pathogen responsible for tuberculosis. A primary pathologic feature of M. tuberculosis infection is the formation of a granuloma. Immune cells migrate to the lung and then through the lung to the site of infection to form a granuloma. This structure contains the infection, and is often maintained for a long period of time. The signals responsible for granuloma formation and maintenance are largely unknown. Since chemokines and chemokine receptors direct cells to specific sites within the tissues, it is plausible that these cells participate in granuloma formation. In this review, the current literature on chemokines and M. tuberculosis infection, as well as the specific role that tumor necrosis factor alpha (TNF-alpha) plays in granuloma formation and chemokine expression are discussed.