The Anti-tumor Ability Of DC/Tumor Fusion Cell Vaccine Can Be Enhanced By MIP-10 Load Folic Acid Modified Chitosan Nanoparticles And The Study On Its Mechanism

In recent years,tumor biological immunotherapy as a new type of cancer treatment is gradually known by people.Anti-tumor vaccines based on Dendritic cells(DCs)one of the hot spots of research.The fusion vaccine of DCs and tumors cells is an extremely promising anti-tumor strategy and has a wide range of applications in the tumor immunotherapy.DC/tumor fusion vaccines research has developed rapidly and has also entered clinical trials.DC/tumor fusion vaccines can kill tumor cells.But the immune microenvironment of tumor will hinder the CTLs to local tumor,so the effect of DC/tumor fusion vaccines aren’t good.Thus,improving the anti-tumor activity of DC/tumor fusion vaccines is critically important for the treatment of cancers.The IFN-induced protein-10(IP-10)can bind to its receptor,CXCR3,which is expressed on activated T cells,macrophages and NK cells.Given that the number of activated T cells infiltrated in the tumors is crucial for tumor-specific T cell immunity,a new approach to recruit more effector T cells may enhance tumor-specific T cell responses and control the progression of tumors.In order to enhance the anti-tumor activity of DC/tumor fusion vaccines in vivo,we have developed the bioreactor of Folic acid to use it for liver cancer in mice model.Objective:To prepare the bioreactor of FA-chitosan/mIP10 and investigate the anti-tumor effects and the underlying mechanisms of FA-chitosan/mIP10 in mouse HCC model.Methods:Mouse IP-10 plasmid was encapsulated into FA-chitosan to obtain FA-chitosan/mIP10 by complex coacervation.Fourier transform infrared spectroscopy(FTIR)were used to evaluate the production of mannoselipid.Dynamic light scattering instrument(DLS)and scanning electron microscope(SEM)were applied to characterize the particle size,morphology,and zeta potential of FA-chitosan/mIP10.The gel retardation assay was used to ensure that IP-10 plasmid was successfully encapsulated into the conjugated compounds of FA-chitosan.The phagocytosis experiment was conducted to confirm the specifically targeting to Hepal-6 of FA-chitosan.We employed a mouse model of Hepal-6 in C57BL/6 mice,and subcutaneous injection of FA-chitosan/mIP10 and DC2.4/Hepal-6 fusion cells was applied to treat HCC in mice.To determine the anti-tumor immunity of both FA-chitosan/mIP10 and DC2.4/Hepal-6 fusion cells in vivo,we measured tumor growth and mouse survival.Furthermore,flow cytometry was used to measure the frequency of CXCR3+CD8+T cells and myeloid-derived suppressor cells(MDSCs).Enzyme-linked immunospot assay(ELISPOT)were used to measure the levels of interferon-gamma(IFN-y).In addition,the IP-10 protein expression of local tumor vascular,density,proliferation,and apoptosis of tumor cells were evaluated using immunological histological chemistry staining.Results:The successful development of FA-chitosan/mIP10 can effectively target liver cancer cells Hepal-6.The combination treatment of FA-chitosan/mIP10 and DC2.4/Hepal-6 fusion cells significantly inhibited the growth of tumor,prolonged the survival time of mice in HCC-bearing mice,recruited CXCR3+CD8+ T cells to the local tumor,increased the expression of IP-10 protein,and decreased the MDSCs in spleen and the bone marrow.And the combination treatment also stimulated the spleen to secrete higher levels of IFN-y,inhibited the proliferation of tumor cells,and promoted apoptosis of tumor cells in HCC-bearing mice.Conclusion:The bioreactor of FA-chitosan/mIP-10 can increase the effect of the fusion cells DC2.4/Hepal-6 to against tumors,which may be a promising strategy for the intervention of human HCC tumor in the clinic.