ABSTRACT
@#ObjectiveTo investigate the anti-tumor effect of agonist MnCl_2of a novel cyclic guanosine monophosphate-adenosine monophosphate synthase(c GAS)/stimulator of interferon genes(STING)pathway collaborated with tumor cell lysate(Lysate)and the neo-antigen 10K-Adpgk of mouse colon cancer MC38 cell line.MethodsBone marrow-derived dendritic cells(BMDCs)were extracted from mouse bone marrow and divided into three groups:PBS,1 μmol/L MnCl_2and 10 μmol/L MnCl_2,which were analyzed for the maturation by flow cytometry,determined for the concentration of IL-6 in supernatant by ELISA,and detected for the transcription levels of IL-6,IFN-α,IFN β and CXCL9 genes by q PCR.Mouse tumor model was established by using MC38 cell line.When the tumor volume reached 100 mm3,the mice were randomly divided into two groups for administration,PBS,Lysate,MnCl_2,10K-Adpgk,Lysate + MnCl_2group and Lysate +10K-Adpgk + MnCl_2combined treatment group,which were administered subcutaneously through the tail for 3 times,with each interval of 1 week,and measured for the tumor volume every 2 days.One week after the last dose,serum samples were collected and determined for the concentrations of IFNγ and TNFα by ELISA.The tumor and spleen were isolated.The proportions of tumor infiltrating T cells and T cells in peripheral blood mononuclear cells(PBMCs)and the ratio of T cells to memory T cells in spleen were detected by flow cytometry,and the proportion of antigen specific T cells in spleen was detected by ELISPOT.Results10 μmol/L MnCl_2stimulated the maturation of BMDCs and activated the subsequent immune process.The tumor volumes of mice in the combined treatment group were considerably smaller than those in PBS group,the contents of IFNγ and TNF-α in serum were higher than those in other groups,and the proportions of tumor infiltrating T cells,T cells in PBMCs and ratio of T cells to memory T cells in spleen were also significantly higher than those in PBS group.Combined therapy caused strong antigen-specific T cell immune response.ConclusionThe addition of the novel adjuvant MnCl_2significantly enhanced the treatment effect of tumor cell lysate and neo-antigen,which provided an experimental basis for the development of the combination tumor treatment method based on MnCl_2and tumor antigens.