The long-lived immunological synapse: mechanical perspective of regulatory T cell-mediated peripheral immune tolerance

The 2025 Nobel Prize in Physiology or Medicine honors the discovery of regulatory T cells (Tregs) and the Foxp3 gene as the key regulator of peripheral immune tolerance, preventing autoimmunity by suppressing aberrant immune responses. Notably, Tregs are also highly infiltrated in tumors and interfere with anti-tumor immunity. Building on these foundational insights, this perspective explores how mechanical cues, often overlooked in immunology, underpin Treg function, particularly at the immunological synapse (IS). We synthesise emerging evidence suggesting that Tregs form a mechanically long-lived IS, characterised by enhanced stability, reduced force generation, and mechanotransduction signaling. We hypothesise that this architecture, potentially influenced by Foxp3-regulated cytoskeletal dynamics, is essential for the tolerance mechanisms elucidated by the Nobel committee. By bridging biomechanics with immune biology, we reveal critical knowledge gaps in Treg mechanobiology and highlight how understanding these fundamental principles could inform the development of novel diagnostic and therapeutic strategies for autoimmune diseases, transplantation, and cancer immunotherapy.