New insights to B cell tolerance involving the mechanosensitive ion channel Piezo1.

B cell tolerance is critical for preventing autoimmunity, yet the mechanisms by which B cells discriminate self from non-self antigens remain incompletely understood. While early findings emphasize the role of classical antigen-mediated BCR signaling strength by varying antigen formats, emerging evidence highlights the importance of mechanical cues during antigen recognition. This review explores how mechanosensitive ion channels, particularly Piezo1, contribute to B cell activation and tolerance by integrating physical forces at the immune synapse. We discuss how membrane-bound and particulate antigens induce mechanotransduction through Piezo1, promoting enhanced B cell responses by extracellular calcium influx. Additionally, we consider the differential roles of Piezo1 in various physiological contexts, including shear stress, tissue migration, and substrate stiffness. Understanding mechanosensormediated signaling in coordination with other pathways such as antigen recognition, T cell help, or cytokine signaling expands our knowledge of B cell biology and introduces a new paradigm for modulating humoral immunity in health and disease. [BMB Reports 2026; 59(5): 253-261].