Since the proper activation of T cells requires the physical interaction with target cells through the formation of immunological synapses (IS), an alteration at this level could be a reason why tumors escape the immune response. As part of their life cycle, it is thought that T cells alternate between a static phase, the IS, and a dynamic phase, the immunological kinapse (IK), depending on high or low antigen sensing. Our investigation performed in tissue samples of human glioma shows that T cells are able to establish synapsing interactions not only with glioma tumorigenic cells, but also with stromal myeloid cells. Particularly, the IS displaying a T cell receptor–rich (TCR-rich) central supramolecular activation cluster (cSMAC) is preferentially established with stromal cells, as opposed to malignant cells. Conversely, T cells in the malignant areas showed distinct morphometric parameters compared with nonneoplastic tissue — the former characterized by an elongated shape, well-suited to kinaptic dynamics. Importantly, high-resolution 3-dimensional analyses demonstrated the existence of bona-fide IK preferentially arranged in malignant areas of the tumor. This imbalance of IS/IK states between these 2 microenvironments reveals the low antigenic sensing of T cells when patrolling tumorigenic cells and reflects the immunoevasive environment of the tumor.
Laura R. Díaz, Elena Saavedra-López, Leire Romarate, Izaskun Mitxitorena, Paola V. Casanova, George P. Cribaro, José M. Gallego, Ana Pérez-Vallés, Jerónimo Forteza-Vila, Clara Alfaro-Cervello, José M. García-Verdugo, Carlos Barcia Sr., Carlos Barcia Jr.
Three-dimensional reconstructions of synapses.