Monocyte-derived Macrophages: the Supplements of Hepatic Macrophage in Echinococcus Multilocularis Infected Mice

Abstract

Background Alveolar echinococcosis (AE) is a potentially lethal zoonosis caused by the cestode Echinococcus multilocularis. The aim of this research is to investigate the dynamic changes of monocytes, macrophages and related cytokines in animal models of persistent infection of Echinococcus multilocularis, specifically exploring the possible immune changes in infection of Echinococcus multilocularis.Methods An infection model was established by intraperitoneal injection of a protoscolex suspension. The pathological changes of mice liver were observed by HE staining and the score scale of infection was established. The ratio of Ly6Chi and Ly6Clo Monocytes in peripheral blood of mice was detected by flow cytometry. The distribution and expression of CX3CL1, CX3CR1, iNOS, CD163 and CD11b in mouse liver were detected by immunohistochemistry. The mRNA expression levels of TNF-α and Arg1 in mouse liver were detected by qRT-PCR. The expression levels of INF-γ, IL-17, IL-4 and IL-10 in peripheral blood of mice were detected by ELISA.Results The results of HE staining showed that significant lesions appeared in the later stages of infection in the liver. The results of the infection degree score scale showed that the severity score value increased with the prolongation of the infection time. The results of flow cytometry showed that the proportion of Ly6Chi monocytes in the peripheral blood of the experimental group mice was decreased after a brief rise, Ly6Clo monocytes decreased first and then increased. The results of immunohistochemistry showed that the expression of CX3CL1, CX3CR1, CD11b, CD163 and iNOS in the mice liver of the experimental group was increased. The results of qRT-PCR showed that the expression level of TNF-α and Arg1 mRNA in the liver of the experimental group mice increased. The results of ELISA showed that the expression level of IFN-γ, IL-17, IL-4 and IL-10 increased with the duration of infection.Conclusions Monocytes as a supplement to hepatic macrophage, monocytes and kupffer cells (KCs) both participate in Th1 and Th2 immune responses of the body by differentiating into M1 or M2 at different stages of Echinococcus multilocularis infection.