The effects of attenuated Salmonella carrying IL-2/NK4 double gene on immune function in mice / 中国生物制品学杂志

ABSTRACT

@#Objective To study the effects of attenuated Salmonella(Ty21a-pIRES-IL-2-NK4,TPIN)carrying interleukin-2(IL-2)/4-kringle antagonist of hepatocyte growth factor(NK4)double gene on humoral and cellular immune function.Methods Eighteen BALB/c mice,half male and half female,were randomly divided into control group(1. 5 mL 10%NaHCO3 by gastric tube feeding),Ty21a group(0. 1 mL Ty21a by gastric tube feeding)and TPIN group(0. 1 mL TPIN by gastric tube feeding),with 6 mice in each group. The immunization was boosted twice 7 d after the initial immunization. At 21d after administration,the blood samples were collected from eyeballs and the serum was separated,which was detected for the serum IgG antibody level by ELISA. The thymus and spleen of mice were isolated aseptically,and the spleen cells were stimulated by Ty21a and TPIN respectively in vitro. After 72 h,the proliferation ability of spleen cells was measured by CCK-8 assay,and the expression level of cytokines in spleen cells was detected by ELISA. The spleen and thymus were weighed,the spleen and thymus indexes were analyzed,and HE staining was performed.Results Compared with the control group and Ty21a group,the serum IgG level(F = 111. 74,P < 0. 01)and the contents of IFNγ,IL-4 and IL-10 in spleen cell supernatant(F = 38. 21,11. 37 and 26. 92,respectively,each P < 0. 05)increased significantly,as well as the spleen and thymus indexes(F = 10. 419 and 5. 859,respectively,each P < 0. 05)showed significant increase. In mice of Ty21a and TPIN group,the thymus cortex widened,lymphocytes increased,and there was mild inflammatory reaction;the white pulp and lymphocytes in spleen increased with neutrophil infiltration.Conclusion TPIN has a good immune protective effect,and can significantly stimulate the body to produce humoral immunity and cellular immunity,which may have a good therapeutic effect on tumors.