Human T-cell surface protein tactile (CD96) Protein

Background

The CD96 molecule, also known as TACTILE (T-cell-activated increased late expression), is a transmembrane glycoprotein predominantly expressed on the surface of NK cells and certain subsets of T cells. This protein plays a crucial role in the regulation of immune responses, specifically within the innate immune system, by modulating the activity of NK cells. CD96 is part of the immunoglobulin superfamily and is closely related to other checkpoint receptors such as TIGIT (T cell immunoreceptor with Ig and ITIM domains) and CD226. It has structural and functional similarities with these receptors, which are involved in immune cell interactions and responses to cellular stress signals, infection, and malignant transformations. CD96 binds to the ligand CD155, also known as poliovirus receptor (PVR), which is broadly expressed on various cell types, including endothelial cells and tumor cells. Through its interaction with CD155, CD96 modulates NK cell cytotoxicity and plays a part in controlling the inflammatory response and immunological synapse formation between NK cells and target cells. By balancing activating and inhibitory signals, CD96 ensures immune homeostasis, minimizing the risk of autoimmune responses while enabling effective pathogen and tumor surveillance.