Human CD300a binds to phosphatidylethanolamine and phosphatidylserine, and modulates the phagocytosis of dead cells.

ABSTRACT: CD300a is an immunoreceptor tyrosine-based inhibitory motif (ITIM) containing molecule that belongs to the CD300 family of paired activating/inhibitory receptors. It has been shown that its ligation inhibits activation signals on cells of both myeloid and lymphoid lineages. The ligands for CD300a have not been identified. Here, we show that a CD300a-Ig fusion protein specifically binds to apoptotic cells that are evolutionary apart, such as human and insect cells, suggesting that the ligand has to be conserved. Using surface plasmon resonance, ultracentrifugation, ELISA, and reporter cell assays, we identified phosphatidylethanolamine (PE) and phosphatidylserine (PS), 2 phospholipids that translocate to the outer leaflet of the plasma membrane of dead cells, as the ligands for CD300a. Muta

SUBMITTER: Simhadri VR 

PROVIDER: S-EPMC3327458 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature