Objective:To understand the expression levels of Tim-3,a new proinflammatory factor in the early stages of Echinococcus granulosus infection in mice.Methods: BALB/c mice were infected with E.granulosus.Peritoneal macrophages and spleen cells were collected at 1,5,9 and 13 days post-infection.At different time points ,the levels of Tim-3 in peritoneal macrophages and spleen CD3+lymphocyte subsets were detected by FCM , and the relative expression of TLR 4 mRNA was detected by qRT-PCR.Results:There was no significant difference in the expression levels of Tim-3 of CD3+spleen lymphocyte subsets between E.granulosus group and control group (P>0.05).The expression levels of Tim-3 of spleen macrophages (9,13 days) and peritoneal macrophage (5,9,13 days) were much higher in E.granulosus infected group than those in control group with statistical significance (P<0.05).The numbers of macrophages were no change.Compared with control groups,the relative expression of TLR4 mRNA at 1 day post-infection was statistically higher in E.granulosus infected group ( P<0.05 ).Conclusion:During early stage of E.granulosus infection in mice,the levels of Tim-3 expression are upregulated,while the expression of TLR4 are downregulated,which may inhibit the function of macrophages resulting in host-immunity-defensive-system inhibition and immune tolerance of E.granulosus to host.

Objective:To investigate the effects of TGF-β1 on T lymphocytes of BALB/c mice infected with Echinococcus granulosus( E.granulosus ) in vitro.Methods: The inhibitor group:the spleen cells of BALB/c mouse were co-cultured with E.granulosus and SB525334.The control group:the spleen cells of BALB/c mouse were co-cultured with E.granulosus and PBS.The blank group:the spleen cells of BALB/c mouse were co-cultured with RPMI-1640 medium and SB525334.The lymphocytes were collected at 48 h post-infection.The T lymphocyte subsets, the number of CD4+CD25+T cells, the number of NK cells, and the expression of NKG2D receptor were detected by flow cytometry.The NK cell activity was determined with the lactate dehydrogenase leakage assay(LDH).Results:The inhibition the TGF-β1 receptors resulted in the increase of in the number of CD4+T cells,the decrease in the number of CD8+T cells,the increase of in the ratio CD4+/CD8+T cells,the decrease of in the number of CD4+CD25+T cells,the increase in the expression of the NKG2D receptors,the increase in the lysis rate of Yac-1 cells by NK cells,and a positive cor-relation between the expression of activity receptor NKG2D and killing activity of NK, which were mediated by E.granulosus.Conclusion: The inhibition of TGF-β1 receptors can enhance the immune response of T lymphocytes against E.granulosus infection in vitro.

Objective To investigate the prokaryotic expression and immunoreactivity of BspE,a type Ⅳ secretion protein of Brucella,and the effect of recombinant protein BspE on cytokines.Methods According to the BspE gene of Brucella M5-90 published in GenBank,the gene fragments were synthesized by a company and then ligated into PUC57 vector for sequencing.The sequenced gene was cloned into a prokaryotic expression vector pET-28α and transformed.Induced expression was performed in E.coli DE3 competent cells.The obtained target protein was purified by a Ni-NTA affinity column,and its reactogenicity was analyzed by Western blotting.Mouse RAW264.7 cells were treated with 25 g/L BspE recombinant protein for 12,24,48 h,and the control group was treated with the same amount of BSA instead of BspE,and enzyme-linked immunosorbent assay (ELISA) was used to detect interleukin (IL)-1β level.Results The recombinant expresed plasmid of pET-28α-BspE was successfully obtained.The results of Western blotting showed a single band with a relative molecular mass of about 30.1 × 103,and the recombinant protein BspE had good reactogenicity,and IL-1β levels (ng/L)were significantly elevated by the recombinant protein BspE (12 h:43.27 ± 2.13 vs 30.24 ± 1.66,24 h:57.78 ± 3.44 vs 41.22 ± 1.22,48 h:72.52 ± 3.04 vs 46.77 ± 2.75,t =8.38,7.86,10.89,P ＜ 0.05).Conclusions BspE recombinant protein has better immunoreactivity and can increase the expression level of IL-1β in mouse macrophages.This study provides a scientific basis for the role of effector proteins in the pathogenesis of Brucella.

In order to explore the role of BspE protein in Brucella infection,yeast two-hybrid tech-nique was used to screen host cell proteins that interact with BspE protein.The constructed BspE recombinant plasmid pGBKT7-BspE was used as bait plasmid to hybridize with the RAW264.7-cD-NA library of mouse mononuclear macrophages by yeast two-hybridization technique.The positive clones were extracted by plasmid,sequenced and co-immunoprecipitation to determine the host cell proteins that could interact with BspE.The subcellular localization of BspE proteins was analyzed by confocal laser microscopy.The physical and chemical properties,protein structure and function of BspE interacting proteins were analyzed by bioinformatics.The siRNA for one of the BspE inter-acting proteins was synthesized,the expression of its gene was silenced in HEK293T cells,and the silenced cells was infected with Brucella M5-90 and the number of intracellular bacteria was coun-ted.The results showed that the decoy plasmid pGBKT7-BspE was successfully constructed,and the plasmid could express BspE protein in yeast.Eight positive clones were obtained from the host cell genome library by yeast two-hybridization.The positive clones were identified as RBM27 and PCBP1 by sequencing,backcross and co-immunoprecipitation.Bioinformatics was used to predict the cell location,protein structure and amino acid composition of RBM27 and PCBP1.After siRNA interference,the expression level of PCBP1 was significantly decreased and the amount of M5-90 in the cell was increased.Brucellosis secreted protein BspE interacts with host proteins RBM27 and PCBPl,and PCBP1 negatively regulates the proliferation of Brucellosis.