Nectin-like protein 2 defines a subset of T-cell zone dendritic cells and is a ligand for class-I-restricted T-cell-associated molecule.
Galibert L., Diemer G.S., Liu Z., Johnson R.S., Smith J.L., Walzer T., Comeau M.R., Rauch C.T., Wolfson M.F., Sorensen R.A., Van der Vuurst de Vries A.-R., Branstetter D.G., Koelling R.M., Scholler J., Fanslow W.C., Baum P.R., Derry J.M., Yan W.
Dendritic cells (DCs) are a phenotypically and functionally heterogenous population of leukocytes with distinct subsets serving a different set of specialized immune functions. Here we applied an in vitro whole cell panning approach using antibody phage display technology to identify cell-surface epitopes specifically expressed on human blood BDCA3(+) DCs. A single-chain antibody fragment (anti-1F12 scFv) was isolated that recognizes a conserved surface antigen expressed on both human BDCA3(+) DCs and mouse CD8alpha(+) DCs. We demonstrate that anti-1F12 scFv binds Nectin-like protein 2 (Necl2, Tslc1, SynCaM, SgIGSF, or Igsf4), an adhesion molecule involved in tumor suppression, synapse formation, and spermatogenesis. Thus, Necl2 defines a specialized subset of DCs in both mouse and human. We further show that Necl2 binds Class-I-restricted T-cell-associated molecule (CRTAM), a receptor primarily expressed on activated cytotoxic lymphocytes. When present on antigen presenting cells, Necl2 regulates IL-22 expression by activated CD8(+) T-cells. We propose that Necl2/CRTAM molecular pair could regulate a large panel of cell/cell interactions both within and outside of the immune system.