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Objective This study aimed to investigate the effect of splenic CD11clow CD45RBhigh dendritic cell (DC)derived from endotoxin tolerance (ET)mice on the expression of zinc finger protein A20 in acute liver failure (ALF)and to clarify the possible mechanism.Methods ET mice were modeled. CD11clow CD45RBhigh DC were isolated from spleen by magnetic activated cell sorting (MACS).One hundred and twenty-six healthy male BALB/c mice were randomly divided into four groups:control group (group A,n=6),ALF group (group B,n =40),normal CD11clow CD45RBhigh DC-treated group (group C,n=40),ET-CD11clow CD45RBhigh DC-treated group (group D,n=40).Mice in group B,C and D were injected with D-galactosamine (D-GalN)600 mg/kg and lipopolysaccharides (LPS)10 μg/mouse.Mice in group A were given the same volume of normal saline (NS).Half an hour after the D-GalN/LPS injection,mice in group C were treated with splenic CD11clow CD45RBhigh DC derived from normal mice (1 ×10 6/mouse,0.2 mL/mouse).Mice in group D were treated with splenic CD11clow CD45RBhigh DC derived from ET mice (1 × 10 6/mouse,0.2 mL/mouse).Mice in group A and B were given the same volume of 0.9% NaCl solution (0.2 mL/mouse).Alanine aminotransferase (ALT)and aspartate aminotransferase (AST)levels were measured at each time point.Liver histopathological changes were confirmed by hematoxglin and eosin methods.Expressions of tumor necrosis factor-α (TNF-α),nuclear factor-kappa B (NF-κB),and zinc finger protein A20 were measured by reverse transcriptase polymerase chain reaction(RT-PCR)and Western blot.One-way analysis of variance was used to compare means between groups.Normal distribution and homogeneity of variance were tested.LSD test was conducted in patients accorded with homogeneity of variance.Results ALT and AST levels increased 2 h after modeling in group B and peaked at 24 h,which were significantly higher than groups A (t = 31 .00, 11 .52,both P <0.05).ALT and AST levels also increased after 2 h after modeling and peaked at 24 h in group C and group D,which were both significantly higher than group B (t =14.60,26.43,both P <0.05).The mRNA levels and protein expressions of TNF-αand NF-κB in group B increased gradually and peaked at 12 h after D-GalN/LPS injection.Compared to that of group A,the differences were both statistically significant (t = 427.58,122.42,179.35 ,165 .98,all P < 0.05 ).The mRNA level and protein expression of zinc finger protein A20 in group B decreased gradually and reached the minimum at 12 h after D-GalN/LPS injection,which was statistically different compared to group A (t = 90.80, 160.43,both P <0.05).On the contrary,the levels of zinc finger protein A20 in group C and D increased gradually and peaked at 12 h after D-GalN/LPS injection.The expression level of zinc finger protein A20 in group D was significantly higher than group C (t = 11 .21 ,24.80,both P < 0.05 ).Conclusion Treatment of splenic CD11clow CD45RBhigh DC derived from ET mice contributes to liver protection against D-GalN/LPS-induced ALF.
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Objective To isolate and culture splenic CD11clow CD45RBhigh dendritic cells (DC) derived from endotoxin tolerance (ET) mice and investigate its biological characterization.Methods Mice weighed 20 to 25 gram were completely randomized into two groups including ET group and control group with 6 each.ET mice were modeled by intraperitoneal injection of low-dose lipopolysaccharide (LPS) for several days (pretreated with LPS 0.1 μg/mouse for 5 d).Mice in control group were given the same volume of normal saline (NS).CD11clowCD45RBhighDC were isolated from spleen by magnetic activated cell sorting (MACS).The immunological phenotypes were detected by flow cytometry.The suppressive capacity of CD11clow CD45RBhigh DC was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay in allogenic mixed T cells reaction.The expressions of interleukin (IL)-10 and IL-12 produced by CD11clow CD45RBhigh DC were measured by enzyme-linked immunosorbent assay (ELISA).Statistical significance was analyzed through one-way analysis of variance (ANOVA).The homogeneity of variances was detected by Levene test.If variances were homogeneous,the least significant difference (LSD) test was used.If not,Dunnett T3 test was applied.Results The consistence of CD1 1 clow CD45RBhigh DC in control group was 30 ％,reaching the amount of (5.30±0.12) × 105/mouse ;In ET group,the percentage of CD11clow CD45RBhighDC achieved 80 ％ and the production was (1.20 ± 0.13) × 106/mouse the difference was statistically significant (t=3.23,P＜0.01).The cellar morphology in two groups showed no obvious difference.Compared to expression levels of all cell phenotypes (histocompatibility complex-Ⅱ,CD40 and CD80) in normal mice,the cell surface expression levels of CD11clowCD45RBhigh DC in ET mice were much lower.The difference in two groups was statistically significant.Splenic CD11clowCD45RBhighDC derived from ET mice with cell concentration of 1∶ 10,1∶50and 1∶100 had more obvious prohibitory effects on allogenic T cells (t1∶0 =1.36,P1∶10 ＜0.01,t1∶50 =2.49,P1∶50 ＜0.01,1∶100 =1.88,Pm00 ＜0.01).Secretion of IL-10 produced by CD11clowCD45RBhighDC of ET mice was significantly increased (t1∶0=13.63,P1∶10 ＜0.01,t1∶50 =13.45,P1∶50 ＜0.01,t1∶00 =9.31,P1∶00 ＜0.01),but the expression of IL-12 was lower (t1∶0 =2.62,P1∶0 =0.02,1∶∶50 =2.74,P1∶0=0.02,t1∶100 =2.99,P1∶100 =0.01).Conclusion Splenic CD11clow CD45RBhigh DC from ET mice have weaker ability of antigen presenting and allogeneic lymphocytes proliferation stimulating than those from normal mice.
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Objective To study the effect of endotoxin tolerance (ETT) on chemokine receptor 7 (CXCR7) in the liver tissue of rats with acute liver failure (ALF).Methods SD male rats were randomly divided into three groups:normal group,ALF group and ETT group.The rats in the ETT group and ALF group were injected with lipopolysacharide (LPS) 0.1 mg/kg or saline respectively,one time / day for 5 days.At 24 hours after the 5th-day injection,all rats were injected with D-GalN 800 mg/kg and LPS 8μg/rat.Blood sample and liver tissue were collected on 2,6,12,24 and 48 hours after injection.The gene expressions of CXCR7 in the liver were measured by RT-PCR,and the protein expressions of CXCR7 were determined by Western Blot.The data analysis was performed by LSD,Dunnett's t test.Results The histological damage in the liver tissue was significantly mider in ETT group compared to ALF group.The gene expressions of CXCR7 were significantly milder in ETT group compared to ALF group (2 h:F =29.222,6 h:F=166.892,12 h:F=38.975,24h:F=34.603,48 h:F=18.929,allP＜0.01),but still severer than that of normal group.The CXCR7 protein expression in ALF group and ETT group peaked at 24 hours,but the expression of CXCR7 in ETT group was lower compared with that in in ALF group (2h:F=11.155,6 h:F=42.553,12h:F=17.082,all P＜0.01; 24 h:F=7.242,P＜0.05).Conclusions During the process of endotoxin tolerance,LPS pretreatment and D-GalN can decrease the liver injury,down-regulate the expressions of CXCR7mRNA and CXCR7.This suggests that CXCR7 may play an important role in the ETT.
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Objective To investigate the mechanism of endotoxin tolerance (ETT) through observing the expression of OX40 in liver tissues of ETT rats.Methods SD male rats were randomly divided into three groups:normal group (n=6),acute liver failure (ALF) group (n=24) and ETT group (n=24).Lipopolysacharide (LPS) 0.1 mg/kg (ETT groups) or 0.9 ％NaC1 (ALF groups) was administered by five consecutive intraperitoneal injections at 24 h intervals,and at the sixth day,all animals were treated with intraperitoneal injections of D-galactosamine (D-GalN) 800 mg/kg and LPS 8 μg/rat.Blood and liver tissue were collected at 6,12,24 and 48 hours after the injection of D-GalN/LPS.The gene expression of OX40 in the liver was measured by reverse transcription-polymerase chain reaction (RT-PCR).The protein expression of OX40 was estimated by Western blot.The tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels were determined by enzyme-linked immunosorbent assay (ELISA).The data analysis was performed by one-way ANOVA,lease significant difference (LSD) and Dunnett's T3 test.Results The expressions of TNF α and IL-6 were both significantly lower in ETT group compared to ALF group,but still higher than that of control group.The gene expressions of OX40 peaked at 12 hours and decreased gradually in ALF group.The gene expressions of OX40 were significantly lower in ETT group compared to ALF group (6 h:F=5.027,24 h:F=5.539,48 h:F=5.011,all P＜0.05; 12 h:F=36.688; P＜0.01),but still higher than that of normal group.The tendency of OX40 protein expression in ALF group was peaked at 12 hours and decreased at 24 hours.In ETT group,the expression of OX40 was lower,and the difference between ETT group and ALF group had statistical significance (6 h:F=8.658,P＜0.05; 12 h:F=34.611,24 h:F=28.176,48 h:F=16.747; all P＜0.01).Conclusions The level of OX40 is increased in ALF group,while the expressions of OX40,TNF-α and IL-6 are lower in ETT group,which suggested that OX40 may play an important role in the process of ETT.
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Objective To obtain M. Tuberculosis Ag85A protein by prokaryotic expression. Methods The fbpA gene encoding M. Tuberculosis Ag85A protein was amplified by polymerase chain reaction ( PCR) from M. Tuberculosis H37R_V strain. The PCR product was cloned into prokaryotic expression vector pProEXHTb to generate the recombi-nant plasmid pProfbpA, which was then transformed into the competence Escherichia coli BL21 cells. The recombi-nant Ag85A protein was successfully expressed by isopropyl thio-β-D-galactoside(IPTG) induction and purified by the Ni-purification system. The distribution of fbpA gene in different nonpathogenic mycobacterial strains was screened by PCR and ELISA was performed to determine the immunoreactivity of the recombinant Ag85A protein with serum from mice with mycobacterial infections. Results 32 ku Ag85A protein was successfully expressed and purified. It was confirmed by PCR and ELISA that fbpA gene presented in the genomes of M. Tuberculosis H37Rv, H37Ra, BCG, M. Smegmatis, M. Terra, M. Trivial and M. Phlei, but being absent in the genomes of M. Vaccae. The highest Ag85 A antibody titer was found in serum of TB patients and mice infected by M . Tuberculosis H37Rv .Conclusion The recombinant Ag85A protein was successfully expressed and purified.