Schematic representation of the mechanotransduction pathway that enables B cells to extract and present immobilized antigens. B cells sense substrate stiffness by the BCR, leading to the nuclear translocation of YAP 1 and the export of the ATAT1 to the cytoplasm. This results in increased MT acetylation, facilitating the release of GEF-H1 at the IS, which in turn promotes actin foci formation. Simultaneously, acetylated MTs serve as stabilized tracks for lysosome positioning at the IS, thereby enhancing antigen extraction and presentation.