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Objective:This study is designed to investigate the toxicity of lipoprotein (L16) and non-lipoprotein (U16) of Brucella outer membrane protein (OMP) 16 on osteoblasts. Methods:Recombinant L16 and U16 proteins were prepared by using prokaryotic expression system of Escherichia coli ( E. coli) BL21 (DE3) and purified by Ni column. Using group design, mouse osteoblasts (MC3T3 cells) were co-incubated with L16 and U16, respectively. Brucella lipopolysaccharide (LPS) stimulus was used as the positive control, and cells without any stimulation were used as the negative control. Incubation time was 24 h. The activity of co-incubated MC3T3 cells were detected by CCK-8; the supernatant of cultured cells was collected and the release rate of lactate dehydrogenase (LDH) in the supernatant was detected by bioluminescence, and the virulence of L16 and U16 on MC3T3 cells was evaluated. Annexin Ⅴ-PE/7-AAD double staining flow cytometry was further used to analyze the apoptosis rate of MC3T3 cells, and the activation level of apoptosis executive protein Caspase-3 was detected by Western blotting (WB). Results:The activity of MC3T3 cells in L16 group [(56.16±1.63)%] was significantly lower than that in U16 and LPS groups [(97.02±1.44)%, (98.64±0.90)%, P < 0.01], the LDH release rate [(84.64±0.96)%] was significantly higher than that in U16 and LPS groups [(34.82±3.41)%, (26.75±1.95)%, P < 0.01]. Annexin Ⅴ-PE/7-AAD double staining results showed that the apoptosis rate was (46.45±2.19)% in L16 group, while the remaining groups were all less than 1%. WB results showed that activated Caspase-3 (cleaved-Caspase-3) existed in L16 stimulated cells, but not in U16 stimulated cells and LPS control cells. Conclusion:L16 can induce the apoptosis of osteoblasts and inhibit the proliferation of osteoblasts, but U16 has no obvious effect indicating that Brucella L16 with complete lipid structure is necessary for virulence effect.
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Objective:Using the monoclonal antibody to Brucella Omp31, flow cytometry (FCM) method for detecting Brucella antigens is established, and to analyze its potential value in clinical diagnosis. Methods:The supernatants of sonicated proteins (SSPs) from Brucella abortus (2308, 104M and S19), Brucella melitensis (M5-90), and Brucella suis (S2) were identified by Western blotting and enzyme-linked immunosorbent assay (ELISA) with monoclonal antibody (mAb) 5H3 to Brucella Omp31, which were prepared by breaking Brucella species with ultra-sonication. The recombinant eukaryotic plasmid (pcDNA3.1-Omp31) was constructed and transfected in 293FT cells, and the expression of Omp31 was detected by Western blotting. THP-1 cells were infected by Brucella melitensis M5-90 strain to simulate mononuclear phagocytes carrying with Brucella spp. To identify the ability of mAb 5H3, FCM for detecting intracellular Brucella was established, mAb 5H3 was labeled with fluorescein isothiocyanate (FITC-5H3) or P-phycoerythrin (PE-5H3), and then the transfected 293FT cells and THP-1 cells invaded by M5-90 strain were individually identified by FCM with FITC-5H3, and sensitivity of FITC-5H3 in FCM was tested. The PBMCs collected from brucellosis patients or normal blood donors were tested by FCM with double mAbs including PE-5H3 and FITC-CD14 to evaluate this method's feasibility in clinical practice. Results:MAb 5H3 was able to identify Brucella melitensis (M5-90) and Brucella suis (S2), as well as Brucella abortus (2308, 104M and S19) with Omp31 gene deletion. The mAb 5H3 labeled with FITC or PE was used for identifying Brucella antigen in various cells by FCM. The results revealed that the proportion of 293FT positive cells expressing Omp31 was about 59.3%, and the proportion of THP-1 positive cells infected by vaccine strain M5-90 was about 6.2%. In addition, the sensitivity of FCM with FITC-5H3 for the 293FT cells transfected with pcDNA3.1-Omp31 was about 4%. The FCM based on double mAbs staining of PE-5H3 and FITC-CD14 was preliminarily established. For brucellosis patients, the proportion of cells (1.93%) stained with the double mAbs in PBMCs was higher than that of normal blood donors (< 0.30%, negative) in FCM. Conclusions:A FCM assay is preliminary established basing on mAb 5H3 against Omp31 for detecting intracellular Brucella. Moreover, we have found that mAb 5H3 could recognize Brucella abortus originally lacking Omp31, which reduces the defect of Omp31 applied in all Brucella species detection. The development of this FCM assay provides a new strategy and usable reagents for brucellosis pathogens diagnosis.
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Objective To investigate the percentage of regulatory T cells (Treg) in peripheral blood lymphocytes of patients with chronic brucellosis and the percentage change before and after treatment of different regimens,and to analyze the influence of Treg cell-induced immunosuppression on the therapeutic effect of chronic stage brucellosis.Methods Using case-control study,35 patients with chronic brucellosis who were hospitalized in Heilongjiang General Hospital of Agriculture Bureau [28 males,7 females,aged (45.37 ± 20.16) years old] were selected as case group.According to the treatment regimen,they were divided into standard treatment group (15 cases) and immune enhancer group (20 cases),the treatment was 20 d;30 cases of in-hospital health examinations were selected [16 males and 14 females,aged (35.53 ± 11.38) years old] as control group.Peripheral blood sample of the subject was collected before and after the treatment,the Treg cells as a percentage in peripheral blood lymphocytes were detected by flow cytometry.And the percentage change of Treg cells of brucellosis patients who underwent different treatment regimens was analyzed.Results Before treatment,the percentage of Treg cells in peripheral blood lymphocytes of the control group,the standard therapy and the immune enhancer groups [(1.69 ± 0.38)％,(3.12 ± 0.86)％,(3.05 ± 1.07)％] was significantly different (F =25.89,P ＜ 0.05);compared with the control group,the percentage of Treg cells in the peripheral blood lymphocytes of the standard treatment group and the immune enhancer group increased (P ＜ 0.05);there was no significant difference between the standard treatment group and the immune enhancer group (P ＞ 0.05).After treatment,the percentage of Treg cells in peripheral blood lymphocytes of the control group,the standard therapy and the immune enhancer groups [(1.69 ± 0.38)％,(3.06 ± 0.76)％,(2.85 ± 0.89)％] was significantly different (F =30.84,P ＜ 0.05);compared with the control group,the percentage of Treg cells in the peripheral blood lymphocytes of the standard treatment group and the immune enhancer group increased (P ＜ 0.05);there was no significant difference between the standard treatment group and the immune enhancer group (P ＞ 0.05),and compared with the same group before the treatment,respectively,the differences were not statistically significant (P ＞ 0.05).Conclusions The percentages of Treg cells in peripheral blood lymphocytes of the chronic brucellosis patient are not significantly changed before and after different treatment regimens.It suggests that the immunesuppression induced by Treg cells may be one of the reasons why the host organism cannot effectively remove residual Brucella in the body,which leads to chronic infection.
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Objective To investigate the role of mutations in C region that may contribute to occult hepatitis B virus infection.Methods C genes were amplified from two OBI blood donor samples respectively.Plasmids with mutations in C region of hepatitis B virus were constructed by overlapping PCR.HBsAg and HBeAg in Huh7 cells and in the serum of Balb/c mice were detected by CMLA.HBcAg in liver tissue was detected by immunohistochemistry,while HBV-RNA was tested by RT-PCR.Results Mutations in C region significantly reduced the expression level of HBeAg and HBcAg,but had no significant effect on HBsAg and HBV-RNA.Conclusion The mutations in C region affect the expression level of HBeAg and HBcAg,which may play an important role in the occurrence of OBI.
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Objective To investigate the humoral and cellular immune responses in patients with acute brucellosis, and evaluate dynamic changes of regulatory T-lymphocytes (Foxp3+ Treg) in the peripheral blood of patients during treatment, in order to clarify the relationship between immunosuppression and the therapeutic effect in human brucellosis.Methods Sixty-five patients with brucellosis hospitalized at the Third Department of Infectious Diseases, Heilongjiang Agriculture and Reclamation Bureau General Hospital between July 2015 and November 2015 were included.Twenty-eight patients were treated with conventional therapy (group A: patients received 3 courses of treatment.Each lasted for 20 days with one-week interval), and 37 patients were treated with conventional therapy in combination with immunopotentiator (group B).Thirty healthy volunteers were enrolled as the controlled group.The ratio of CD3+CD4+ Foxp3+ Treg cells in the peripheral blood of brucellosis patients were measured by flow cytometry (FCM) at the end of each course of treatment.Data in accordance with normal distribution were described as mean±standard deviation.Comparison between two groups was done by two sample t test.Comparison among multiple groups was performed by analysis of variance and SNK test.Data that did not fit the normal distribution were analyzed by multiple-sample nonparametric test.Results After the first (20 d), second (50 d) and third course of treatment (80 d), the ratios of Foxp3+Treg in the peripheral blood of 65 acute brucellosis patients were 2.83%, 3.77% and 4.03%, respectively, which were all significantly higher than control group (1.69%;t=5.97, 9.05 and 5.66, respectively, all P0.05), while those were both higher than control group (t=7.09 and 4.94, respectively;both P<0.01).At the end of the second course, the ratio of Foxp3+ Treg in group B was higher than group A (t=2.22, P<0.01), and both of them were higher than control group (t=10.79 and 7.25, respectively;both P<0.01).At the end of treatment, Foxp3+ Treg in group A was also significantly higher than the other two groups (t=6.02 and 6.45, respectively;both P<0.01).Conclusions In patients with acute brucellosis treated with the standard antibiosis treatment in combination with immunopotentiator, the ratio of Foxp3+Tregs significantly increases and maintains at a high level, which suggests that extra immunopotentiator may be not helpful for the treatment of brucellosis at the very early stage.
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We produced and identified the monoclonal antibodies against Brucella melitensis U‐lipoprotein OMP19 .A DNA fragment coding omp19 of Brucella melitensis was amplified by PCR ,and inserted into the vector of pET‐30a(+ ) ,the result‐ant recombinant plasmid ,which we designated as pET‐30a(+ )/omp19 .We then transformed the plasmid into BL21(DE3) competent cells for the expression of the OMP19 protein .After induction with different concentrations of IPTG ,the colleted cells were analyzed by SDS‐PAGE ,and then OMP19 monoclonal antibodies were prepared through hybridoma technology . These mAbs were tested to reactivity to rOMP19 and nature membrance proteins (NMP) of Brucella melitensis by Western blot and IEST .We successfully constructed an expression vector of pET 30a(+ )/omp19 .An IPTG‐induced expression of the OMP19 protein (19 kDa in molecular weight) was demonstrated by SDS‐PAGE .The fusion protein existed in the form of solu‐ble ,and the OMP19 protein of high purity could be obtained by Ni‐NTA .Western blot assay showed that the refolded protein could be recognized by the anti‐serum against Brucella melitensis .Twenty‐three mAbs to OMP19 was produced in which 91 .30% were IgG1 ,twenty‐two (95 .65% ) mAbs could recognize nature OMP19 protein ,and eighteen (78 .26% ) mAbs could recognize NMP ,four mAbs could react with Brucella melitensis .The protein maintained good immunogenicity and twenty‐three mAbs were obtained ,which we believe provides a good protein candidate for the immunological research .
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Objective To evaluate the oxacillin disk screening test for screening Streptococcus pneumoniae by the penicillin Etest method.Methods 96 clinically isolated non-meningitis strains of Streptococcus pneumoniae were collected.The sensitivity and spe-cificity of the oxacillin disc screening test was evaluated by the penicillin Etest method as a standard method for detecting the peni-cillin susceptibility.Results Among 96 non-meningitis strains of Streptococcus pneumoniae,the penicillin-susceptible Streptococcus pneumoniae(PSSP)strains detected by the penicillin Etest method accounted for 96.9%(93/96),the penicillin intermediate Strep-tococcus pneumoniae(PISP)strains accounted for 3.1%(3/96)and no penicillin resistant Streptococcus pneumoniae(PRSP)strain was found.But 16 PSSP strains were detected by the oxacillin disc screening test with the sensitivity of 17.2% and the specificity of 100.0%,respectively.The difference between the oxacillin disc screening test and the penicillin Etest method was statistically sig-nificant(χ2 =77,P <0.01 ).Conclusion The oxacillin disc screening test has the low sensitivity for preliminarily screening non-meningitis strains of Streptococcus pneumoniae.Most of Streptococcus pneumoniae must be detected by the minimum inhibitory concentration(MIC)methods such as the penicillin Etest method.
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Objective To assess the behavior of children with tic disorder (TD),and to analyze the behavioral characteristics among children with TD at different clinic conditions.Methods Sixty-three children with TD were evaluated with Child behavior checklist (CBCL).ANOVA and t-test were used to analyze the difference in the total and individual scores of CBCL in the children classified according to the different clinical types,the severity of TD,and comorbid attention-deficit hyperactivity disorder(ADHD).Results There were no significant differences among the total and individual scores of CBCL in the patients of the different clinic types( P ＜ 0.05 ) ;the scores of body complain in the patients in moderate to severe conditions (4.15 ± 2.34) were higher than that of those in mild condition ( 2.68 ± 2.22 ) ( t =- 2.540,P =0.014) ; the scores of attention problem (9.94 ± 3.57 ),disciplinary offence ( 3.94 ± 3.06 ),aggressive behavior ( 15.39 ± 5.12 ),exportoriented behavior problems ( 13.98 ± 7.34)and behavior problem (47.89 ± 17.51 )in TD comorbid ADHD were higher than in simple TD group ( 7.31 ± 3.34,2.44 ± 2.22,7.24 ± 4.93,9.78 ± 6.55,37.07 ± 17.98 ) ( t =- 2.774,- 2.166,- 1.930,- 1.956,- 2.174,P =0.007,0.034,0.048,0.04 1,0.034 ).Conclusion Children with TD at different clinical conditions have varied behavioral problems and behavioral characteristics,while comorbid ADHD is the most significant factor to affect TD patient's behaviors.
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Objective To replace the endogenous CTL epitope LLD in HBsAg with EYILSLEEL of glypican(GPC3)in order to prepare a GPC3-HBsAg multiple peptides vaccine for HBV infection.Methods The HBsAg/GPC3 DNA was amplified by gene splicing by overlap extension(SOEing)PCR from pcHBsAg plasmid and then inserted into pBSSK+ vector to construct a pBSSK/GPC3 vector.The vector was then identified by PCR,double digesting and sequencing.The fragment encoding GPC3 CTL epitope EYILSLEEL was obtained by double digesting the plasmid pBSSK/GPC3 and then inserted into pcDNA3.1+ vector.Results Sequencing and restrict endonulease digestion indicated that eukaryotic expression vector pcDNA-HBsAg/GPC3 was constructed successfully.Conclusion The endogenous CTL epitope LLD of HBsAg is replaced by the EYILSLEEL,and an eukaryotic expression vector pcDNA-HBsAg/GPC3 is constructed.