Flt-3 ligand, in combination with bovine granulocyte-macrophage colony-stimulating factor and interleukin-4, promotes the growth of bovine bone marrow derived dendritic cells

Culture of bone marrow precursor cells with cytokines, including granulocyt e-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and t he tyrosine kinase receptor binding proteins Flt-3 ligand (Flt-3L) and stem -cell factor (SCF), has previously been shown, in both mouse and. human, to result in the generation of large numbers of dendritic cells. We extend th ese findings to bovine dendritic cells. Culture of bovine bone marrow cells with GM-CSF, IL-4 and either Flt-3L or SCF enhanced the generation of low buoyant-density dendritic cells. However, only the addition of Flt-3L to ce lls cultured with GM-CSF and IL-4 was shown to increase the number of dendr itic cells and induce the differentiation of dendritic cells with potent ca pacity to stimulate allogeneic T cells and resting CD4(+) memory T cells. T he effective ability to stimulate T cells was associated with the expressio n of major histocompatibility complex (MHC) class II molecules and CD80/86 by dendritic cells. Bovine bone marrow derived dendritic cells appeared to be exclusively of myeloid origin because they expressed the myeloid-related antigens CD14, MyD-1 and CD11b.