Immunopathogenesis of Non-Tuberculous Mycobacteria Lung Disease

In recent years, the incidence and prevalence of non-tuberculous mycobacteria lung disease (NTM-LD) has been increasing worldwide. In Korea, <i>Mycobacterium avium</i> complex (MAC) and <i>Mycobacterium abscessus</i> complex account for most common cause of NTM-LD. It is essential to elucidate the pathophysiology of NTM-LD. The pathophysiology of NTM-LD has not been fully understood, however, it can be divided into bacterial and host-side factor. Among the host factor, innate immunity plays an essential role in the initial host immune response against intracellular non-tuberculous mycobacteria (NTM), and adaptive immunity also has a role. However, the role of these immunity in mycobacterial disease has been mainly studied in tuberculosis, but studies on its role in NTM are limited. In this review, I focus on NTM innate and adaptive immunity, the role of macrophages and neutrophils, and host interaction in NTM infection.