Fms-related tyrosine kinase 3 ligand

Fms-related tyrosine kinase 3 ligand (Flt3L) is a growth factor that stimulates the proliferation and differentiation of hematopoietic stem cells by binding with other growth factors and promotes the expansion of NK cells and dendritic cell subsets. Flt3L is produced by T cells and stromal fibroblasts and targets various cells, including hematopoietic stem cells, B cells, T cells, dendritic cells, and NK cells. Flt3L binds to the homologous receptor tyrosine kinase Flt3 and activates the JAK/STAT signaling pathway.

Flt3L is a hematopoietic four-helix bundle cytokine that is structurally homologous to stem cell factor (SCF) and colony-stimulating factor 1 (CSF-1). It contains four conserved cysteines and two glycosylation sites. The extracellular portion of Flt3L is approximately 160 amino acid residues in length, while the cytoplasmic segment is about 20-30 amino acid residues long.