FMS-like tyrosine kinase 3 ligand

FMS-like tyrosine kinase 3 ligand (also known as FLT3L) is a growth factor that regulates the development of hematopoietic cells, the cells that give rise to all other blood cells. It is a member of a small family of growth factors that includes stem cell factor (SCF) and colony-stimulating factor 1 (CSF-1).

FLT3L binds to and activates the FMS-like tyrosine kinase 3 (FLT3) receptor, a class III receptor tyrosine kinase. This binding and activation leads to the proliferation, differentiation, and survival of hematopoietic cells. FLT3L is essential for the development of the immune system and is particularly important for the generation of dendritic cells, which are key regulators of immune responses.

FLT3L is produced by various cell types, including T cells and bone marrow stromal cells. It is also found in the plasma and serum of healthy individuals. The level of FLT3L in the blood can be used as a biomarker for certain diseases, such as acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS).

FLT3L has been used in clinical trials as a therapeutic agent to boost the immune response in cancer patients. It has also been used to enhance the efficacy of cancer vaccines.

Structure

FLT3L is a soluble protein that is secreted by cells. It is composed of a single polypeptide chain that is folded into a compact, globular structure. The protein has a molecular weight of approximately 30 kilodaltons.

Function

FLT3L binds to the FLT3 receptor on the surface of hematopoietic cells. This binding activates the receptor, triggering a cascade of intracellular signaling events that lead to the proliferation, differentiation, and survival of the cells.

Clinical significance

The level of FLT3L in the blood can be used as a biomarker for certain diseases. Elevated levels of FLT3L have been observed in patients with AML and MDS. In these patients, the high level of FLT3L is thought to reflect an increased demand for hematopoietic cells.

FLT3L has been used in clinical trials as a therapeutic agent to boost the immune response in cancer patients. It has been shown to increase the number of dendritic cells, enhancing the body's ability to mount an immune response against cancer cells.

See also

• FMS-like tyrosine kinase 3
• Hematopoietic stem cell
• Dendritic cell
• Acute myeloid leukemia
• Myelodysplastic syndromes