Figure 8.

Immunoregulatory mechanisms involving miRNA in macrophages, dendritic cells and T cells: Three primary mechanisms of immune regulation are documented: (i) Autophagy evasion: Autophagy can degrade intracellular Mtb by autolysosomes. Mtb regulates the expression of various miRNAs thereby inhibiting autophagy activation and aiding its survival inside macrophages. (ii) Apoptosis impairment: Host macrophages combat infection by eliminating niche cells for Mtb growth and by packaging tubercle bacilli in apoptotic bodies. Mtb employs multiple strategies to circumvent this programmed cell death. (iii) Inflammation obstruction: Mtb infection initiates the activation of various components of the immune system resulting in recruitment of inflammatory cells. Mtb interferes with various downstream signalling events and inhibits the inflammatory responses thereby thriving within the hostile environment. (miRNAs shown in red are downregulated and green are upregulated).