Expressions and activation of JAK2 and STAT5 during the process of differentiation of human cord blood CD34~+ cells into dendritic cells / 第三军医大学学报

ABSTRACT

Objective To understand the roles of JAK STAT pathway in the process of differentiation of human cord blood CD34 + hematopoietic stem cells into dendritic cells (DCs) by detecting the expressions and activation of JAK2 and STAT5. Methods CD34 + hematopoietic stem cells isolated from human umbilical cord blood and cultured for two weeks were induced to differentiate into DCs in vitro . Total cellular JAK2 and STAT5 and tyrosine phosphorylated protein stimulated by granulocyte/macrophage colony stimulating factor (GM CSF) at different time points (0, 7, and 14) during DC differentiation were detected by Western blotting. Results The amount of JAK2 protein was similar at 0, 7, and 14 d without GM CSF stimulation. With the differentiation of cells into DCs, the amount of tyrosine phospho JAK2 induced by GM CSF increased markedly. Both total cellular and tyrosine phospho STAT5 expression increased markedly during DC differentiation. Maximal tyrosine phospho STAT5 expression was later than JAK2. Conclusion JAK STAT pathway may take part in the signal mechanism of DCs differentiation from CD34 + hematopoietic stem cells stimulated by GM CSF.