T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT)

TIGIT (T cell immunoreceptor with immunoglobulin and ITIM domains) is an inhibitory immune checkpoint receptor expressed on subsets of T cells (such as CD8+, CD4+, and regulatory T cells) and natural killer cells[1][2][4]. It belongs to the immunoglobulin superfamily and regulates immune responses by binding with high affinity to the poliovirus receptor (CD155, also known as PVR) and with lower affinity to CD112 (PVRL2) on dendritic cells, macrophages, and some tumor cells[1][2][3][4]. Engagement of TIGIT leads to intracellular inhibitory signaling via ITIM/ITT-like motifs, suppressing T cell proliferation, activation, and cytokine production, and inhibiting NK cell cytotoxicity[4][3]. TIGIT is upregulated in tumor-infiltrating lymphocytes and other dysfunctional immune cells in cancer and chronic infections such as HIV, making it an important therapeutic target in immuno-oncology and infectious disease[1][2]. Blockade of TIGIT (alone or in combination with anti-PD-1/PD-L1 therapies) is under active clinical investigation as a means to enhance anti-tumor and antiviral immune responses[2][5][6]. Note: Transforming growth factor beta receptor is a completely different target and should be treated separately—mixing these names in a single target entry is incorrect.

Other names

T cell immunoreceptor with Ig and ITIM domainsWUCAMVstm3TIGIT

Blockade of inhibitory immune checkpoint to restore T cell and NK cell effector function Synergistic activation of T cells when combined with PD-1/PD-L1 blockade