Altered Lysine Lactylation Modulates host Defense Against Tuberculosis via Mitochondrial Protein Regulation

Tuberculosis (TB) remains a major global health threat, and the emergence of drug-resistant strains highlights the urgent need for host-directed therapies. Metabolic reprogramming, particularly the shift toward aerobic glycolysis and subsequent lactate accumulation, is a hallmark of TB, yet whether lactate-driven protein lactylation contributes to host defense remains unknown. Here, we show that lactate levels and global lysine lactylation (Kla) are significantly elevated in both TB patients and Mtb -infected macrophages. Through comprehensive lactylome profiling, we identified widespread reprogramming of Kla sites in TB, with mitochondrial proteins being the predominant targets and enriched in metabolic pathways including the TCA cycle and fatty acid oxidation. Functional screening of mitochondrial lactylated proteins revealed ADAR and ACSF2 as two key regulators of intracellular mycobacterial survival. Functionally, we demonstrate that lactate supplementation potentiates, while lactylation inhibition attenuates, the functional effects of these proteins, and that site-specific lysine lactylation is essential for their activities. Collectively, our findings establish a critical link between lactate metabolism, protein lactylation, and host antibacterial defense, identifying ADAR and ACSF2 as potential targets for therapeutic intervention against TB.