The Specific Anti-gastric Cancer Effects Of DC Modified By SOCS1Antagonists (pJAK2Polypeptide)

Objective: To investigate the way to prepare dendritic cells (DCs) modified withsuppressors of cytokine signaling1antagonist (pJAK2polypeptide) in vitro, and toobserve its specific killing effect of gastric cancer.Methods: Peripheral blood of healthy human was collected and the peripheralblood mononuclear cells (PBMCs) were isolated. DCs were induced in the presenceof rhGM-CSF and rhIL-4; medium was changed every three days, and equivalentcytokines were added. On the fifth day, they were divided into three groups: controlgroup, antigen-loaded group and polypeptide modified group. After4hours, rhTNF-αand LPS were added into each group, and cells were harvested for experiment after24hours. Then the morphological features of DCs were observed by invertedmicroscope every day; the phenotype changes were detected by flow cytometry; theproliferative ability of autogenous T cells stimulated by mDCs of different groupswas evaluated by MTT assay; the killing effect of cytotoxic T lymphocyte (CTL) togastric carcinoma cells was evaluated by LDH cytotoxicity test; the concentration ofIL-12and IFN-γ was detected by ELISA.Results: Dendritic cells were obtained successfully and they all had the typicalmorphology features. When the antigen concentration was0.1mg/mL, the expressionlevel of immunophenotyping was higher than mDC group（P <0.05）. Meanwhile,polypeptide modified group had higher expression of CD83, CD80, CD86andHLA-DR than mDC group (P <0.01), and had the highest expression when thepolypeptide concentration was30μM. In the mixed lymphocyte culture for96hours,the stimulation index of each group mDCs to autogenous T cells was the highestwhen the ration of DCs to T cells was1:10. When the ratio of effector cells to targetcells was from5:1to20:1, the CTL killing effect had a positive correlation. When theratio of effector cells to target cells was20:1, CTL activity level of Ly+p-30μM groupwas (40.42±3.13)%, higher than the Ly-0.1mg/mL group significantl（yP <0.01）.Theconcentration level of IL-12was increased obviously after the stimulation of rhTNF-αand LPS; the concentration in Ly+p-30μM group was (426.44±28.89)pg/mL, higher than Ly-0.1mg/mLgroup obviously(P <0.01). The IFN-γ level of Ly+p-30μM groupwas higher than Ly-0.1mg/mL group (P <0.01).Conclusions: pJAK2polypeptide can enhance the antigen presentation andspecific antitumor effect of dendritic cells towards gastric carcinoma cells.