TABLE 2.
Useful markers of cell function and differentiation
| Cell marker | Alternative name | Function and/or comment | Presented in vivo |
|---|---|---|---|
| CD11a | LFA-1; integrin αL subunit | Associates with CD18, up-regulated in inflammation; LFA-1 mediates lymphocyte adhesion by binding ICAM-1 and also binds ICAM-2 and -3 | Leukocytes |
| CD11b | Integrin αM subunit; Mac-1, CR3, C3biR | Associates with CD18, up-regulated in inflammation; this complex serves as a receptor for the iC3b component; Mac-1 also serves as an adhesion molecule for ICAM-1 | Granulocytes, monocytes, NK cells |
| CD11c | Integrin αX subunit; p150/95 | Associates with CD18; up-regulated in inflammation | Granulocytes, monocytes, macrophages, NK cells, T- and B-cell subsets |
| CD16a | Transmembrane form of FcγRIIIA/FcγRIIIB | Low-affinity receptor for aggregated IgG | NK cells and neutrophils |
| CD16b | GPI-linked form of FcγRIIIb | Low-affinity receptor for human IgG | Only expressed on neutrophils (granulocytes) |
| CD18 | Integrin β2 subunit | Associates with CD11a, -b, -c, -d | Leukocytes |
| CD32 | Fc receptor RII | Low-affinity receptor for aggregated IgG | Monocytes, granulocytes, B cells |
| CD35 | CR1; C3b receptor | Binds complement C3b and C4b and enhances phagocytosis | Monocytes, granulocytes, B cells, erythrocytes, dendritic cells, NK cells |
| CD54 | ICAM-1 | Mediates adhesion through the binding of LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18) | Endothelial and activated cell types |
| CD71 | T9, transferring receptor | Intracellular adhesion | Proliferating cells, activated T- and B-cells, macrophages |
| CD89 | Fcα receptor R, Fcα-R, IgA Fc receptor, IgA receptor | Binds both monomeric and polymeric forms of either IgA1 or IgA2 at the boundary between the Cd2 and Cd3 domain, induces phagocytosis, degranulation, respiratory burst, and killing of microorganisms | Eosinophils, neutrophils, monocytes, and alveolar macrophages |
| Annexin-5 | Lipocortin 5, endonexin 2, VAC-a, anchorin CII, PAP-1 | Calcium binding protein which interacts with acidic membrane phospholipids; during the early stages of apoptosis, the phosphotidyl serine molecule flips on the cell membrane, exposing an external binding site for annexin-5 | Marker of early, middle, and late cellular apoptosis |
| FMLP receptor | Chemotactic peptide receptor | Binds formyl-Met-Leu-Phe | |
| P2Y11 | ATP receptor | Binding of ATP during cyclic AMP granulocytic differentiation of HL-60 and NB-4 cells | Granulocytic differentiation |