What is Myeloid cell surface antigen CD33 and its biological function

Human Myeloid cell surface antigen CD33 (CD33) is a type I transmembrane glycoprotein expressed on the surface of myeloid progenitor cells. It is expressed on hematopoietic cells including monocytes, macrophages, neutrophils, dendritic cells, and mast cells. CD33 is also expressed on some B cells, T cells and NK cells.

CD33 is involved in several biological functions, including leukocyte adhesion, antigen presentation, and signal transduction. It is also involved in the regulation of macrophage activation, phagocytosis, and endocytosis. CD33 is thought to play a role in the regulation of immune responses by mediating the activation of T lymphocytes.

CD33 is involved in several diseases, such as Alzheimer's disease, acute myeloid leukemia, and multiple myeloma. It has been suggested that CD33 is involved in the development of Alzheimer's disease by mediating tau hyperphosphorylation and Aβ accumulation. In acute myeloid leukemia, CD33 is involved in antigen presentation, macrophage activation, and signal transduction. In multiple myeloma, CD33 is involved in the regulation of myeloid progenitor cell adhesion and proliferation.

Drugs targeting CD33 have been developed for the treatment of acute myeloid leukemia. One of the most promising CD33 inhibitors is gemtuzumab ozogamicin (GO), which is an antibody-drug conjugate (ADC). This ADC combines a monoclonal antibody targeting CD33 with a cytotoxic agent, allowing for the selective targeting of CD33-positive leukemic cells.

Recent research has revealed that CD33 is involved in the regulation of numerous biological processes. Studies have also suggested that CD33 is a potential therapeutic target for the treatment of various diseases, including Alzheimer's disease and acute myeloid leukemia. In addition, research has shown that CD33-targeted drugs, such as GO, are effective in the treatment of acute myeloid leukemia.