Objective   To investigate the role of JAK2/STAT3 signaling pathway in IL-6-induced suppression during the maturation of mouse bone marrow-derived dendritic cells (BMDCs) after LPS treatment.    Methods   To obtain immature BMDCs

mouse bone marrow cells were isolated and cultured in complete culture medium containing GM-CSF and IL-4 after removing the nonadherent cells. The cell morphology was observed by using a phase contrast inverted microscope. LPS was added into the culture medium of BMDCs to induce the cell maturation. The expression of costimulators and MHC class   Ⅱ    molecules on the surface of LPS-treated BMDCs with or without IL-6 treatment was analyzed by flow cytometry. The expression of p-JAK2

STAT3 and p-STAT3 were detected by Western blot analysis.    Results   DCs were obtained from mouse bone marrow with normal morphology and high purity. Compared with BMDCs incubated with LPS only

LPS-treated DCs cultured in the presence of IL-6 expressed much lower levels of CD40

CD80

CD86 and MHC class  Ⅱ    molecules. The expression level of cytoplasmic p-JAK2 and p-STAT3 in BMDCs treated with both LPS and IL-6 were much higher than in BMDCs treated with LPS only.    Conclusion   JAK2/STAT3 pathway may be involved in the suppression of LPS-induced DCs maturation by IL-6.