CD33 Human

CD33 is a single-pass type I membrane protein that contains two immunoglobulin-like domains: one V-set domain and one C2-set domain . The extracellular portion of CD33 is responsible for binding sialic acids, while the intracellular portion contains immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that are involved in the inhibition of cellular activation .

The primary function of CD33 is to modulate the immune response. It acts as an inhibitory receptor that dampens the activation of immune cells, thereby preventing excessive inflammation and autoimmunity . CD33 achieves this by recruiting phosphatases to its ITIMs, which then dephosphorylate key signaling molecules involved in cell activation .

Recombinant CD33 is a form of the protein that is produced using recombinant DNA technology. This involves inserting the gene encoding CD33 into a suitable expression system, such as HEK293 cells, to produce the protein in large quantities . Recombinant CD33 is often tagged with a polyhistidine tag to facilitate purification and detection .

Recombinant CD33 is widely used in research and therapeutic applications. It is utilized in studies investigating the role of CD33 in immune regulation and its potential as a therapeutic target for diseases such as acute myeloid leukemia (AML) . CD33 is the target of gemtuzumab ozogamicin (Mylotarg®), an antibody-drug conjugate used in the treatment of AML .

Recombinant CD33 is typically provided as a lyophilized powder and should be stored at -20°C to -80°C to maintain its stability . It is recommended to aliquot the protein to avoid repeated freeze-thaw cycles, which can degrade the protein .