Extracellular matrix reprogramming by the YAP/TAZ/TGF-β2 axis drives immune exclusion in cholangiocarcinoma models

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), key effectors of the Hippo pathway, are often hyperactivated in cancer, promoting tumor progression and therapy resistance. Their oncogenic role depends on interaction with TEA domain (TEAD) transcription factors, making the TEAD-YAP/TAZ complex a promising therapeutic target. Using translational mouse models, we show here that sustained systemic depletion of YAP and TAZ (YAP/TAZ) caused severe side effects. These could be avoided through pulsed inhibition, which effectively suppressed tumor growth, even at advanced stages. We identified Tgfb2 as a critical YAP/TAZ target gene for tumor formation and demonstrated that YAP/TAZ drove T cell exclusion via activation of tissue-remodeling genes. Consequently, YAP/TAZ inhibition enhanced immune cell infiltration. However, infiltrating T cells rapidly underwent exhaustion. Combining YAP/TAZ inhibition with immune checkpoint blockade reversed this exhaustion and sensitized resistant tumors to immunotherapy. This combination reshaped the tumor microenvironment to support immune cell infiltration and activation, representing a therapeutic strategy that maximizes antitumor immunity while minimizing toxicity.