CD85a/ILT-5

CD85a, better known as immunoglobulin-like transcript 5 (ILT-5, LILRB3), is an inhibitory receptor of the leukocyte immunoglobulin-like receptor family expressed on monocytes, macrophages, granulocytes and dendritic cells. Its extracellular region contains four immunoglobulin-like domains, while cytoplasmic immunoreceptor tyrosine-based inhibitory motifs recruit SHP-1 and SHP-2 phosphatases to dampen activation triggered by Fc receptors and Toll-like receptors. Ligand recognition includes HLA class I molecules and certain sialylated or microbial carbohydrate structures. CD85a is studied for its role in myeloid tolerance, antifungal immunity and as a candidate checkpoint in myeloid leukemia.