Advancing roles of nitric oxide in tuberculosis: Promising targets for novel anti-TB therapeutics

Tuberculosis (TB), a chronic zoonotic infectious disease caused by Mycobacterium tuberculosis (Mtb) infection, remains a major public health burden worldwide. The increasing threatens of multidrug-resistant/extensively drug-resistant TB, human immunodeficiency virus (HIV) co-infection, lack of effective vaccines and diagnosis methods, as well as the low treatment efficacy of anti-TB therapeutics lead to multiple difficulties and challenges in TB control. Host immune defense is critical for the processes and outcome of Mtb infection control due to the complex immune evasion mechanisms of Mtb, thus, it's of vital importance to characterize the host immune responses and mechanisms during Mtb infection. Nitric oxide (NO) has complex physiological functions in different conditions and has been shown to play important roles in the immune defenses against Mtb infection and even direct killings of Mtb, which still requires further systemic evaluations. In this review, we summarized the current understanding for the roles and mechanisms of NO in host defenses during Mtb infection, as well as the role of NO in the occurrence, development and treatment of TB, which may provide theoretical basis for the development of novel strategies in the prevention and control of TB and drug-resistant TB.