Mycobacterial immunevasion—Spotlight on the enemy within

Abstract

Mycobacterial immunevasion-spotlight on the enemy within Discussion on how antibiotic treatment routes Mycobacterium avium to phagolysosomes without eliciting an immune response in human macrophages Mycobacterium avium (Mav) is the medically most important species among the so-called nontuberculous mycobacteria (NTM). NTM are common inhabitants of the soil, and they are frequent residents on showerhead surfaces. 1 Yet, although regular Mav exposure can be assumed to occur, symptomatic infections in immunocompetent people are rare. Thus, in contrast to the more pathogenic M. tuberculosis, Mav is an opportunistic pathogen that mainly affects people with chronic lung disease, for example, those afflicted with cystic fibrosis, young children, and immunocompromised patients. 2,3 Like for all mycobacteria, macrophages are established host cells for Mav, and invasive infections can be associated with impressive granulomas containing specialized macrophages. 4 Mav shares other features with M. tuberculosis, such as latency and persistence, which demand complex antibiotic regimens. On the other hand, Mav is particular with respect to its lifestyle and manipulative properties inside macrophages. In