The Role and Potential Application of IL-12 in the Immune Regulation of Tuberculosis

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health challenge, affecting millions annually and leading to substantial mortality, particularly in developing countries. The pathogen's ability to persist latently and evade host immunity, combined with the emergence of drug-resistant strains, underscores the need for innovative therapeutic strategies. This review highlights the crucial role of interleukin-12 (IL-12) in coordinating immune responses against TB, focusing on its potential as an immunotherapy target. IL-12, a key Th1 cytokine, enhances cellular immunity by promoting Th1 cell differentiation and IFN-γ production, vital for Mtb clearance. By stimulating cytotoxic T lymphocytes and establishing immune memory, IL-12 supports robust host defense mechanisms. However, the complexity of IL-12 biology, including its roles in pro-inflammatory and regulatory pathways, necessitates a nuanced understanding for effective therapeutic use. Recent studies have shown how IL-12 impacts T cell synapse formation, exosome-mediated bystander activation, and interactions with other cytokines in shaping T cell memory. Genetic defects in the IL-12/IFN-γ axis link to susceptibility to mycobacterial diseases, highlighting its importance in TB immunity. The review also addresses challenges like cytokine imbalances seen in TNF-α/IFN-γ synergy, which exacerbate inflammation, and the implications for IL-12-based interventions. Research into modulating IL-12, including its use as an adjuvant and in recombinant vaccines, promises improved TB treatment outcomes and vaccine efficacy. The review concludes by stressing the need for continued investigation into IL-12's molecular mechanisms towards precision immunotherapies to combat TB and its complications.