Regulatory effect of Astragalus Polysaccharides on immune function of mice infected by Brucella suis S2 / 中国免疫学杂志

To study the regulating effect of Astragalus Polysaccharides ( APS) to the mice infected by Brucella suis S2.Methods:120 BALB/c mice were randomly divided into 4 groups:experimental mice were injected APS 1 ml ( 0.4,1.2,3 mg/ml) via peritoneal cavity respectively once a day and the control group was injected with the same volume of saline for 3 days,then infected with Brucella suis S2 1 ml (1×107 L-1 ) by ip.Five mice of each group were killed through eye bloodletting at 1,6,12,24,48, 72 h respectively post-infection with Brucella suis S 2 and the peritoneal macrophage were obtained respectively to make smear.Phagocytic rate and phagocytic index were calculated by the Wright Giemsa staining after infected 1 h.TNF-α,IL-12 and IFN-γlevels of serum at different time points were measured by ELISA.The bacterial load of MΦand spleen were measured by coating method.Results:The phagocytic rate and phagocytic index of MΦin APS 3 dose groups were higher than those of the control group ( P<0.05 ).The microbial load of MΦin APS 3 dose groups at 1 h infected by Brucella suis S 2 were significantly higher than those of control,but significantly lower than those of control at 6,12,24,48,72 h after infected by Brucella suis S2.The microbial load of spleen in APS 3 dose groups at 6 h infected by Brucella suis S 2 were significantly higher than those of control ,but significantly lower than those of control at 12,24,48,72h after infected by Brucella suis S2.The concentrations of TNF-α,IL-12 and IFN-γin the serum of APS groups had significantly been improved ( P<0.05 ).Conclusion: APS can promote the activation of MΦin vivo and strengthen the activity of phagocytosis and killing to Brucella suis S 2.APS can promote the secretion of TNF-α,IL-12 and IFN-γof mice,strengthen the cellular immune response of mice to Brucella suis S 2.

Study on Brucella interfering the ubiquitin-dependent autophagic pathway in macrophage / 中华微生物学和免疫学杂志

Objective To investigate the effect on ubiquitin-dependent autophagic pathway in macrophage(MΦ) infected by B.suis S1330 attenuated strains.Methods Infected MΦ in vitro using Brucella S1330 strains to construct experimental model.Observed the process of phagocytic,the level of ubiquitination and autophagy in MΦ of mice.MΦ was divided into control group,infected group,positive control group and infected group after RAPA induced autophagy.The Giemsa staining immunofluorescence and Western blot were applied to observe the chances of ubiquitinated and autophagic protein in MΦ at different time points within different groups.Results Ubiquitinated bacterial protein was detected at 0.5 h after infected MΦ.With the time passing,the ubiquitinated bacterial protein increased and aggregated intracellular until MΦ dead at 12 h after infected.The expression of LC3B protein was serious deficiency in MΦ which infected group,but ubiquitinated bacterial protein decreased significantly in MΦ after RAPA induced.Conclusion Brucella S1330 stain can arouse intracellular ubiquitination process in infected MΦ,and interfere the ubiquitin-dependent autophagic pathway.A large number of aggregated and ubiquitinated bacterial protein can not be effectively removed,it leads to MΦ dysfunction and dead.