We review the structure, cellular distribution, ligand specificity, and function of two emerging types of receptors involved in natural killer (NK) and myeloid cell recognition of other cells: ILT/LIR/MIR and 2B4 receptors. ILT/LIR/MIR receptors are differentially expressed on lymphoid and myeloid cells and two of them, ILT2 and ILT4, recognize HLA class I molecules. Whereas some receptors inhibit, others induce cell activation. 2B4 is broadly expressed on leukocytes, binds CD48, and mediates non-MHC-restricted cytotoxicity by NK cells.
- Cell sulface molecules
- Dendritic cells
- Immunoglobulin superfamily
- Major histocompatibility complex