Abstract:

Objective To discuss the improvement effect of hydatid antigen B （HA-B） on the immune thrombocytopenia （ITP） of the mice， and to clarify its related mechanism. Methods The C57/B6 mice with wild-type （WT） and tumor necrosis factor receptor 2 （TNFR2） gene knockout （TNFR2^－/－） were divided into WT control group， WT-ITP model group， WT-HA-B group， TNFR2^－/－control group， TNFR2^－/－ ITP model group， and TNFR2^－/－ HA-B group. The body weights， organ indexes， and blood routine indexes of mice in various groups were detected. The percentages of M2 macrophages in peripheral blood of mice in various groups were detected by flow cytometry； enzyme-linked immunosorbent assay （ELISA） method was used to detect the levels of Arginase 1 （Arg1）， interleukin-10 （IL-10），inductible nitric oxide synthase （iNOS），and interleukin-6 （IL-6） in serum of the mice in various groups； real-time fluorescence quantitative PCR （RT-qPCR） method was used to detect the expression levels of Arg1， IL-10， iNOS and IL-6 in bone marrow derived macrophages （BMDM） of the mice in various groups. The BMDM of the mice in WT control group and TNFR2^－/－ control group were induced into the M2 macrophages （WT M2 group and TNFR2^－/－ M2 group）. After adding HA-B （WT M2+HA-B group and TNFR2^－/－ M2+HA-B group）， the expression levels of Arg1 and IL-10 mRNA in the cells in various groups were detected by RT-qPCR method. Results Compared with WT control group and TNFR2^－/－ control group， the body weights of the rats in WT-ITP model group and TNFR2^－/－ ITP model group were decreased （P<0.05）， the spleen and thymus indexes were increased （P<0.05）， the platelet counts and red blood cell counts were decreased （P<0.05）， the hemoglobin levels were decreased （P<0.05）， the white blood cell counts were increased （P<0.05）， and the coagulation time were increased（P<0.05）； the percentages of M2 macrophages in the peripheral blood were decreased （P<0.05）， the levels of Arg1 and IL-10 in serum were decreased （P<0.05）， and the levels of iNOS and IL-6 were increased （P<0.05）； the expression levels of Arg1 and IL-10 mRNA in the BMDM were decreased （P<0.05）， while the expression levels of iNOS and IL-6 mRNA were increased （P<0.05）. Compared with WT-ITP model group， the body weight of the mice in WT-HA-B group was increased （P<0.05）， the spleen and thymus indexes were decrease （P<0.05）， the platelet count and red blood cell count were increased （P<0.05）， the hemoglobin level was increased （P<0.05）， the white blood cell count was decrease （P<0.05）， and the coagulation time was decreased （P<0.05）； the percentage of M2 macrophages in the peripheral blood was increased （P<0.05）， the levels of Arg1 and IL-10 in the serum were increased （P<0.05）， and the levels of iNOS and IL-6 in serum were decreased （P<0.05）；the expression levels of Arg1 and IL-10 mRNA in the BMDM were increased（P<0.05）， while the expression levels of iNOS and IL-6 mRNA were decreased （P<0.05）. Compared with WT-HA-B group， the body weight of the mice in TNFR2^－/－ HA-B group was decreased （P<0.05）， the spleen and thymus indexes were increased （P<0.05）， the platelet count and red blood cell count were decreased （P<0.05）， the hemoglobin level was decreased （P<0.05）， the white blood cell count was increased （P<0.05）， and the coagulation time was increased （P<0.05）； the percentage of M2 macrophages in the peripheral blood was decreased （P<0.05）， the levels of Arg1 and IL-10 in the serum were decreased （P<0.05）， and the levels of iNOS and IL-6 were increased （P<0.05）； the expression levels of Arg1 and IL-10 mRNA in the BMDM were decreased （P<0.05）， while the expression levels of iNOS and IL-6 mRNA were increased （P<0.05）. Compared with WT M2 group， the expression levels of Arg1 and IL-10 mRNA in the macrophages in WT M2+HA-B group were increased （P<0.05）； compared with WT M2+HA-B group， the expression levels of Arg1 and IL-10 mRNA in the M2 macrophages in TNFR2^－/－M2+HA-B group were decreased （P<0.05）. Conclusion HA-B can promote the macrophage M2 polarization through TNFR2， thereby exerting the therapeutic effect on ITP.

Key words: Hydatid antigen B, Macrophages M2 polarization, Immune thrombocytopenia, Tumor necrosis factor receptor 2