Studying physiological activity of regulatory T cells (Treg) and the mechanisms of immune suppression utilized by these cells to abrogate excessive inflammation and support immune homeostasis is the hot spot of modern immunology. Treg’s physiological activity is released by both distant and contact mechanisms. In this short review, we briefly describe the main mechanisms of immune suppression used by Treg and the role of these cells in immune homeostasis and pathogenesis of tuberculosis (TB) infection.