Macrophage Infection by Mycobacteria

Mycobacterium tuberculosis is the etiological agent of tuberculosis. It is a pathogen that continues to draw international concerns particularly due to the emergence of multi-drug resistance and to the difficulties associated with the diagnosis and treatment of latent tuberculosis. A key process in the pathogenesis of this disease is the interaction between this pathogen and host macrophages. Invasion of the macrophages protects the pathogen from attack by the immune system, allows it to multiply while protected within the macrophages, and alters the immune response as it influences the profiles of the cytokine and chemokine responses. Key to the intracellular survival of the pathogen within the macrophages is the specific interaction between the pathogen and its virulence factors with the host. This review provides an a summary of pertinent literature on the topic of macrophage receptors utilized by the pathogen, its survival strategies within the macrophage, and the general profile of immune signalling upon exposure to the pathogen. The importance of specific macrophage receptors and certain components of the pathogen to the direction of the immune response are also discussed.