T Cell Immune Synapse Mechanisms Unveiled, Potential for Autoimmune and Cancer Therapies

A Spanish research team from the Autonomous University of Madrid (UAM) and the Spanish National Research Council (CSIC) has identified key mechanisms in the immune synapse that could lead to new therapies for autoimmune diseases and enhanced T cell response against cancer. The research highlights the role of T cells, which are activated when their antigen receptor recognizes and binds to antigens presented by specialized cells, triggering the formation of the immune synapse. This process involves the reorganization of signaling molecules and adhesion receptors at the contact site, facilitating focused secretion towards the antigen-presenting cell. The study showed that the B isoform of FMNL1 is recruited transiently to the immune synapse after T cell antigen receptor activation. Phosphorylation of FMNL1 isoform B at S1086 is crucial for cortical F-actin reorganization and polarization of the T cell secretory machinery towards the immune synapse. These processes coordinate to control focused exosome secretion at the synapse. The findings, published in 'eLife', were led by researchers from the Sols-Morreale Institute for Biomedical Research (IIBM), a joint center of the CSIC and UAM, with collaboration from IdiPAZ, CNIO, and ISCIII.