Malignant tumor is the leading killer of threat to human health. Dendritic cell vaccine-based immunotherapy can activate the immune response, through the identification of tumor associated antigen specific killing of tumor cells without harming normal cells. DCs, the most potent antigen-presenting cells, are the initiator of immune response and occupy a unique place in the induced immune response. But a small number of DCs in vivo are difficult to meet the need of clinical treatment and

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... ic research. To play a physiological role, GH, a protein hormone secreted by the anterior pituitary, must firstly combine with growth hormone receptor (GHR) on the surface of the target cell membranes to pass through the cell membrane. Methods: 10 ng/ml granulocyte-macrophage colony-stimulating factor (GM-CSF) and 5 ng/mlinterleukin-4 (IL-4) were used to stimulate differentiation of umbilical cord blood mononuclear cells (CBMCs) into the immature DCs and further into mature DCs. Cord blood T lympho-cytes were also obtained as a control group. Fluorescence quantitative PCR, western blotting, immunofluorescence and immunohistochemistry (IHC) were used to detect the expression of GHR in DCs group and the control group. Results: After stimulated by GM-CSF and IL-4, CBMCs were differentiated into mature DCs. GHR mRNA expression was significantly elevated in DCs as compared to that in cord blood T lymphocytes. Immunofluorescence and western-blotting analysis revealed that GHR protein expression was also significantly increased in DCs as compared with that in cord blood T lymphocytes. Moreover, IHC results showed that GHR was highly expressed in cytoplasm and nucleus of DCs, which were positively stained brown. Conclusions: CBMCs can be stimulated by the cytokine combination in vitro into DCs. Strongly positive expression of GHR was detected on DCs.