TBK1 enhances antifungal immunity by forming a SRC-TBK1 positive feedback loop in phagosomes of macrophages

TBK1 is a serine/threonine kinase known for its role in antiviral immunity. Here, we identify TBK1 as a key amplifier of antifungal immune responses. Using a mouse model of Candida albicans infection, we show that TBK1 is recruited to phagosomes via SRC-SHP2 signaling and phosphorylates SRC to establish a positive feedback loop. This enhances downstream cytokine production, including IL-6 and TNF-α, and promotes fungal clearance. Bone marrow-derived macrophages (BMDMs) from TBK1fl/fl and TBK1fl/fl Lyz2-Cre mice were stimulated with various fungal components, and RNA-seq was performed to assess transcriptional changes. Our findings define a new role for TBK1 in antifungal host defense and suggest TBK1 as a potential therapeutic target. RNA-seq profiling was performed on BMDMs isolated from TBK1fl/fl and TBK1fl/fl Lyz2-Cre mice. Cells were stimulated with HKCA hyphae, HKCA yeast, Zymosan depleted particles, or left untreated (CTRL) for 30 minutes. Total RNA was extracted, and polyA+ RNA was used for library preparation with the NEBNext Ultra II RNA Library Prep Kit. Sequencing was conducted on the Illumina NovaSeq 6000 platform to obtain 150 bp paired-end reads.