CD33 encodes a myeloid-specific inhibitory receptor belonging to the SIGLEC (Sialic acid-binding Immunoglobulin-like Lectin) family. The receptor recognizes α2-3 and α2-6 linked sialylated glycans and regulates immune cell activation by recruiting the phosphatases SHP-1 and SHP-2 through intracellular ITIM motifs. CD33 is primarily expressed on monocytes, macrophages, myeloid progenitors, microglia, and dendritic cells where it contributes to immune homeostasis, negative regulation of cytokine production, phagocytosis, and inflammatory signaling.
| Official Symbol | CD33 |
| Full Name | CD33 Molecule |
| Aliases | SIGLEC3, GP67, P67 |
| NCBI Gene | 945 |
| Chromosome | 19q13.41 |
| Category | Count |
|---|---|
| Protein Interactions | 479+ |
| Pathways | 9+ |
| Associated Drugs | 39+ |
| Clinical Variants | 29+ |
| Scientific Publications | 930+ |
CD33 is an inhibitory immune receptor expressed on cells of the myeloid lineage. Following binding to sialylated glycans, CD33 activates ITIM-mediated signaling, recruiting SHP-1 and SHP-2 phosphatases to suppress immune activation, regulate cytokine secretion, and maintain immune tolerance. CD33 is an established therapeutic target in acute myeloid leukemia (AML) and is also under investigation for neurodegenerative diseases including Alzheimer's disease.