Effects of interferon-γ on interleukin-10 and mononuclear macrophages in a mouse model of gallbladder cancer

Objective To investigate the effects of interferon-γ (IFN-γ) on interleukin-10 (IL-10) and mononuclear macrophages in a mouse model of gallbladder cancer.Methods Mouse models of gallbladder cancer were constructed by inoculating the human gallbladder cancer cell line GBC-SD subcutaneously in 20 BALB/C mice,and then all the mice were randomly divided into the IFN-γ group and the control group (10 mice in each group).Murine recombinant IFN-γ (0.1 mL,1 × 105 kU/L,diluted with normal saline) was injected into the tumors in the IFN-γgroup,and normal saline was injected into the tumors in the control group.The expression of IL-10 was detected by ELISA,and the numbers of CD14 + cells (mononuclear macrophages),CD64 + cells (M1 macrophages) and CD206+ cells (M2 macrophages) were counted by the immunohistochemistry.All data were analyzed using the Student's t test.Results The mouse models of gallbladder cancer were successfully constructed 1 week later.Nine mice survived in the IFN-γ group,and 7 mice survived in the control group.The tumor weight was (518 ± 138)mg in the IFN-γ group and (669 ± 128)mg in the control group,with a significant difference between the 2 groups (t =2.240,P ＞ 0.05).The volume of the tumor was (456 ± 172)mm3 in the IFN-γ group and (505 ± 146)mm3 in the control group,with no significant difference between the 2 groups (t =1.503,P ＞ 0.05).The concentration of IL-10 was (58 ± 16) μg/g in the IFN-γgroup,which was significantly lower than (102 ± 45) μg/g in the control group (t =2.796,P ＜ 0.05).The number of mononuclear macrophages was 81 ± 16 in the IFN-γ group,which was significantly greater than 50 ± 21 in the control group; the number of M1 macrophages was 66 ± 12 in the IFN-γ group,which was significantly greater than 9 ± 4 in the control group ; the number of M2 macrophages was 15 ± 4 in the IFN-γgroup,which was significantly lower than 40 ± 14 in the control group (t =3.214,13.127,6.914,P ＜ 0.05).Conclusions IFN-γ could decrease the concentration of IL-10 in the tumor microenvironment,and it could induce the mononuclear macrophage to infiltrate into the stroma of the gallbladder cancer cells,and most of the monocytes and macrophages were differentiate to M1 macrophages.Gallbladder neoplasms; Interleukin-10; Interferon-γ; Mononuclear macrophages