TIGIT/DNAM-1/CD155 (PVR) Checkpoint Axis
TIGIT / DNAM-1 / CD155 (PVR) checkpoint axis. A single family of tumour ligands — CD155 (PVR) and CD112 (Nectin-2) — is shared by one activating receptor, DNAM-1 (CD226), and three inhibitory ones, TIGIT, CD96 and PVRIG. Because TIGIT binds CD155 with the highest affinity, it out-competes DNAM-1 and applies the brake. Click any protein for the matching Assay Genie In Vivo functional-grade antibody or ELISA kit.
The PVR / nectin axis is an emerging immune checkpoint that mirrors the CD28/CTLA-4 system. Tumour and myeloid cells display CD155 (PVR) and CD112 (Nectin-2), which are read by competing receptors on NK and T cells. The activating receptor DNAM-1 (CD226) co-stimulates cytotoxicity via Grb2 / Vav1 → PI3K → ERK and NF-κB, driving perforin, granzyme B and IFN-γ.
Three inhibitory receptors oppose it: TIGIT (highest affinity for CD155), CD96 and PVRIG (CD112R). Engaged TIGIT signals through its cytoplasmic ITIM / ITT-like motifs to recruit the phosphatase SHIP-1, which dephosphorylates PI3K, ERK and NF-κB nodes and sequesters Grb2 — damping NK/T-cell activation and promoting exhaustion. Because TIGIT out-competes DNAM-1 for CD155, the net output tilts toward inhibition in the tumour microenvironment.
Checkpoint blockade restores the balance: antibody against the shared ligand CD155 (PVR) frees DNAM-1, and anti-TIGIT is being combined with anti-PD-1 in immunotherapy research. Assay Genie stocks an In Vivo functional-grade anti-CD155/PVR antibody; TIGIT, DNAM-1, CD96, CD112 and the downstream signalling nodes are covered by ELISA kits. For research use only; not for diagnostic or therapeutic procedures. Mouse targets shown.
Every protein node links to a product: CD155/PVR opens the Assay Genie In Vivo antibody; the receptors and signalling nodes open the matching ELISA kit.