TAK1 phosphorylation mediates macozinone (PBTZ169) induced innate immune activation against tuberculosis

ABSTRACT The management of tuberculosis (TB), particularly drug-resistant variants, presents enduring clinical challenges characterized by complex therapeutic regimens, prolonged treatment durations, suboptimal success rates, and significant adverse effects, issues that have persisted as critical concerns in global healthcare. Current TB drug development predominantly focuses on novel compounds and combination therapies targeting pathogen-specific pathways while overlooking the influence of different drugs on host immunity, which is indeed a key factor affecting treatment-related tissue damage and treatment time. In this study, we evaluated the effects of important anti-TB drugs and candidate drugs on host innate immunity and found that PBTZ169 showed potent innate immunity activator, which is a promising drug for the treatment of drug-sensitive and -resistant TB. The expression of cytokines and type I interferon was strongly upregulated by PBTZ169 under lipopolysaccharide (LPS) stimulation and PBTZ169-resistant strain infection, and the innate immune activation enhanced antibacterial activity in macrophages. Mechanistically, PBTZ169 upregulated the NF-kB and MAPK signaling pathways by activating the phosphorylation of TAK1. TAK1 knockdown abrogated PBTZ169-mediated immune activation and antibacterial effects. We thus demonstrate for the first time that PBTZ169 up-regulates NF-κB and MAPK innate immune signaling pathways via activating TAK1 phosphorylation, which may inform clinical deployment strategies and patient selection. IMPORTANCE Maintaining immune homeostasis is paramount for efficient Mycobacterium tuberculosis (Mtb) clearance and tissue repair. Current therapeutic strategies, however, predominantly focus on achieving maximal bacterial suppression within compressed timelines while overlooking the immunomodulatory consequences of anti-tuberculosis agents. This critical knowledge gap underscores the urgent need for mechanistic investigations to establish evidence-based frameworks for optimizing drug combinations and integrating therapies with host-directed approaches.