DNAM-1 (CD226) is a member of the immunoglobulin superfamily and is expressed on NK cells, T cells, monocytes, macrophages, and platelets. Its ligands in humans and mice are the poliovirus receptor CD155 and its family member CD112 (PPR-2 [PVR-related family 2], also called nectin-2). Human CD155 and CD112 are broadly distributed on epithelial and endothelial cells in many tissues; notably, they are overexpressed on various cancers, including colorectal cancer, gastric cancer, and ovarian cancer; neuroblastoma; myeloid leukemias; multiple myeloma; and melanoma. Interactions between CD155 and CD112 on tumor cells and DNAM-1 on NK and T cells augment cell-mediated cytotoxicity and cytokine production; DNAM-1 is likely involved in immunity against CD155- and CD112-expressing malignant tumors. In fact, in a model of chemically induced tumors in DNAM-1-deficient mice, DNAM-1 is important for immune surveillance against CD155-expressing cancers. Therefore, CD155 on tumors is crucial for DNAM-1-mediated cancer immunity.
Iguchi-Manaka A, Okumura G, Kojima H, et al. Increased Soluble CD155 in the Serum of Cancer Patients. Shiku H, ed. PLoS ONE. 2016;11(4):e0152982.