Research progress on the role and dysregulation of NK cells in anti-tuberculosis immunity

Tuberculosis (TB) is one of the most common infectious diseases caused by Mycobacterium tuberculosis (M.tb). The emergence of multidrug-resistant strains, HIV infection, and poor efficacy of the BCG vaccine have made TB epidemics difficult to control. Natural killer (NK) cells are an important component of the body's innate immunity, playing a role not only in the early stages of M.tb infection but also in activating adaptive immune cells to inhibit M.tb proliferation. Recent studies have increasingly revealed significant changes in the number, subsets, and functions of NK cells as TB progresses, with NK cells primarily exhibiting signs of depletion, suggesting a close correlation between NK cell changes and TB progression. Therefore, this article outlines the main changes in NK cells in clinical cohort studies, discusses potential mechanisms of their depletion, and introduces the functions of NK cells, as well as the methods and strategies they use to recognize and kill Mycobacterium tuberculosis. This can contribute to a better understanding of the role and manifestation of NK cells in TB immunity and provide a more comprehensive perspective for NK cell-based TB treatment strategies.