This pathway illustrates the multifaceted interactions between Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv) and Homo sapiens, focusing on immune recognition, metabolic modulation, and virulence-associated transport. At the reception level, host Toll-like receptor 2 (TLR2) recognizes both host-derived regulators (e.g., AldR) and bacterial antigens such as the 6 kDa early secretory antigenic target, initiating innate immune responses. Host lipid signaling is modulated through hydrolysis of phosphatidylinositol derivatives, while nitric oxide synthase 2 serves as a key effector enzyme in antimicrobial defense. Protein interactions reveal bacterial strategies for immune evasion: M. tuberculosis PPE2 inhibits nitric oxide synthase 2, suppressing reactive nitrogen species; phosphate-binding protein PstS1 engages the macrophage mannose receptor to promote uptake; and the low molecular weight protein-tyrosine phosphatase A blocks Caspase-1 activity, interfering with inflammasome-mediated responses. In enzymatic reactions, bacterial alkyl hydroperoxide reductase C detoxifies peroxides, while host enzymes such as dual specificity phosphatase 16 are involved in host-pathogen regulatory exchanges. The transport processes emphasize how M. tuberculosis proteins move from bacterial cytoplasm to host macrophage compartments. Virulence factors including lipoarabinomannan, EsxG/EsxH complexes, Eis, and reductases are delivered into the host cytosol, where they alter immune signaling. Notably, PPE2 can further translocate into the host nucleus, potentially influencing gene regulation and host defense programs. Together, this pathway depicts a dynamic interface where host recognition and antimicrobial mechanisms are counteracted by bacterial modulators, reflecting the balance between pathogen persistence and host immunity during M. tuberculosis infection.

Mycobacterium tuberculosis pathway References