YAP promotes cell-autonomous immune responses to tackle intracellular Staphylococcus aureus in vitro

Growing evidence indicates that YAP/TAZ transcriptional regulators promote autophagy. Here, the authors characterize the role of YAP against Staphyloccocus aureus infection of synovial organoids and describe the role staphylococcal toxins have in antagonizing YAP-mediated functions. Transcriptional cofactors YAP/TAZ have recently been found to support autophagy and inflammation, which are part of cell-autonomous immunity and are critical in antibacterial defense. Here, we studied the role of YAP against Staphylococcus aureus using CRISPR/Cas9-mutated HEK293 cells and a primary cell-based organoid model. We found that S. aureus infection increases YAP transcriptional activity, which is required to reduce intracellular S. aureus replication. A 770-gene targeted transcriptomic analysis revealed that YAP upregulates genes involved in autophagy/lysosome and inflammation pathways in both infected and uninfected conditions. The YAP-TEAD transcriptional activity promotes autophagic flux and lysosomal acidification, which are then important for defense against intracellular S. aureus. Furthermore, the staphylococcal toxin C3 exoenzyme EDIN-B was found effective in preventing YAP-mediated cell-autonomous immune response. This study provides key insights on the anti-S. aureus activity of YAP, which could be conserved for defense against other intracellular bacteria.