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@#Objective To develop and verify a reversed phase high-performance liquid chromatography method for the determination of the purity of recombinant Mycobacterium tuberculosis(Mtb)Ag85b protein stock solution.Methods Fourfactor,three-level orthogonal test was designed,with the area,trailing factor,peak area and peak area RSD as the evaluation indexes to explore the optimal detection conditions. The methodology verification of specificity,linear range,precision and durability was conducted in accordance with the general principles of Chinese Pharmacopoeia(Volume Ⅳ,2020 edition)9101.Results The results of all the evaluation indexes were good when the elution ratio of organic phase was30% ～ 95%,the detection temperature was 35 ℃,the sample volume was 3 μg,and the elution time of 95% organic phase was 15 min. The method had the linear correlation coefficient(R2)of 0. 998 5,the linear range of 1. 8 ～ 4. 2 μg,the reproducibility RSD of 0. 01%,and the intermediate precision RSD of 0. 16%,with good durability under slight changes of column temperature and flow rate.Conclusion The reversed phase high-performance liquid chromatography method for the purity determination of recombinant Mtb Ag85b protein stock solution was developed,which has good specificity,precision and durability,and can be used for the quality control of recombinant Mtb Ag85b protein stock solution.
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PURPOSE: In the present study, the protective immunological markers in serum and peripheral blood mononuclear cells (PBMCs) of bacillus Calmette-Guerin (BCG) vaccinated and unvaccinated children were evaluated after vaccination. Further, PBMCs of children with low protective levels were boosted with BCG, Ag85B, and Ag85B peptides to study their booster effects to increase waning BCG induced immunity. MATERIALS AND METHODS: Fifty children from 1 month to 18 years of age were randomized for the study. Blood samples were collected from 27 participants with/without BCG vaccination. Immunological markers (anti-BCG, interferon gamma [IFN-gamma], and adenosine deaminase activity) were assessed in both serum and PBMCs of children. Children with low levels of protective immunological markers were further recruited and their PBMCs were boosted with BCG, Ag85B, and Ag85B peptides. RESULTS: Children in age group of 4-6 years were associated with significantly (p<0.05) higher BCG-specific IgG and IFN-gamma levels compared to those in age group greater than 10 years. Vaccinated children had greater repertoire of immunological memory which on in vitro stimulation with BCG showed increase in BCG-specific response compared to unvaccinated controls. Assessment of booster effects of BCG, Ag85B, and Ag85B peptides in PBMCs of children revealed greater potential of peptides to boost BCG induced immunity compared to BCG and Ag85B. CONCLUSION: To conclude, children within age 4-6 years are associated with high immunological markers which eventually diminish with age thereby suggesting need for booster dose in later years. Mycobacterium tuberculosis peptides along with BCG may be used as attractive candidates to boost such waning BCG induced immunity in children.
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Child , Humans , Adenosine Deaminase , Bacillus , BCG Vaccine , Immunoglobulin G , Immunologic Memory , Interferon-gamma , Interferons , Mycobacterium bovis , Mycobacterium tuberculosis , Peptides , VaccinationABSTRACT
AIM:To investigate the maturation of mice immature myeloid dendritic cells (mDCs) induced by antigen(Ag)85B of mycobacterium tuberculosis, and the expression of TSLPR and OX40L mediated by TSLP in vitro. METHODS:Recombinant mouse GM-CSF ( rmGM-CSF) and rmIL-4 were used to induce bone marrow precursor cells of C57BL/6 mice to differentiate into immature mDCs in vitro.mDCs were identified followed by purification using CD 11c binding magnetic beads .The morphological characteristic of mDCs was observed under inverted phase-contrast microscope and scanning electron microscope .The surface phenotypes of mDCs were determined by flow cytometry .To obtain the opti-mal concentrations of Ag85B and TSLP, immature mDCs were cultured with different concentrations of Ag 85B or TSLP at 0 (control group), 50, 100 and 200 μg/L for 24 h, and the expression of cell surface molecules CD 80, CD86, TSLPR and OX40L was detected by flow cytometry.In addition, the expression of TSLPR and OX40L in Ag85B and TSLP-co-stimula-ted mDCs was determined by flow cytometry .RESULTS:After 7 d of culture in vitro, the cells showed irregular dendritic protrusions under the inverted-phase contrast microscope , and had wrinkles and dendritic splits under scanning electron mi-croscope , conformed to the morphological characteristics of immature mDCs .The mDCs cells expressed higher level of spe-cific marker CD11c, lower level of co-stimulatory molecules CD80 and CD86, which conformed to the phenotype of imma-ture mDCs.The CD80 +and CD86 +cell ratios of mDCs displayed significant increases in 50, 100 and 200μg/L Ag85B or TSLP groups compared with control group (P<0.05).The ratios of TSLPR +and OX40L+cells did not differ among dif-ferent concentrations of Ag 85B groups.The ratios of TSLPR +and OX40L+cells were significantly increased in 100 μg/L and 200μg/L TSLP groups compared with control group and 50μg/L TSLP group (P<0.05).Under the circumstance of optimal Ag85B or TSLP treatment concentration at 200 μg/L, there was significantly decreased in TSLPR and OX 40L cell ratio of mDCs in Ag85B group or Ag85B combined with TSLP group when compared with TSLP group (P<0.05), and no significant difference among Ag85B group, Ag85B combined with TSLP group and control group was observed .CONCLU-SION: Ag85B enhances mDCs maturation by up-regulating the expression of co-stimulatory molecules CD80 and CD86, and inhibit the expression of pro-inflammatory specific molecules TSLPR and OX40L on TSLP-activated mDCs, indicating that Ag85B modifies the development of asthmatic airway inflammation through the pathway of TSLP -activated mDCs.
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PURPOSE: In the present study booster efficacies of Ag85 B, Bacillus Calmette-Guerin (BCG), and Ag85B peptides were evaluated using prime boost regimes in BALB/c mice. MATERIALS AND METHODS: Mice were primed with BCG vaccine and subsequently boosted with Ag85B, BCG and cocktail of Ag85B peptides. RESULTS: Based on analysis of immune response it was observed mice boosted with Ag85B peptides showed significant (p < 0.001) cytokines levels (interferon gamma, interleukin 12) and BCG specific antibodies (anti-BCG and anti-purified protein derivative titre) compared to booster dose of BCG, Ag85B and BCG alone. CONCLUSION: Our pilot results suggest that prime boost regimes with Ag85B peptides can boost waning BCG induced immunity and may improve immunogenicity of BCG vaccine. However, lot of work is further needed using experimental model of tuberculosis infection to justify the result.
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Animals , Mice , Antibodies , Bacillus , BCG Vaccine , Cytokines , Interleukins , Models, Theoretical , Mycobacterium bovis , Peptides , Pilot Projects , Tuberculosis , VaccinesABSTRACT
Objective: To use in vivo fluorescence image analysis system for evaluating the efficacies of pVAX1-Ag85A and pVAX1-Ag85B DNA vaccines in treatment of bladder cancer cell-implanted tumors in mice. Methods: Discosomasp red fluorescent protein (DsRed) stably transfected bladder cancer BTT cell line (BTT-DsRed) was established and BTT-DsRed cell-implanted mouse model was constructed. Six days later, 24 BTT-DsRed-bearing mice were randomly divided into pVAX1-Ag85A DNA vaccine group, pVAX1-Ag85B DNA vaccine group, and saline group through injecting the pVAX1-Ag85A, pVAX1-Ag85B, and saline into the right hind limbs of mice, respectively. The growth and metastasis of implanted BTT-DsRed tumors were examined by in vivo fluorescence image analysis system. Results: BTT cell line stably transfected with DsRed (BTT-DsRed) was successfully established. Fluorescence visible mouse model was successfully es-tablished by inoculating BTT-DsRed cells into hind limbs of mice. After treatment with pVAX1-Ag85A or pVAX1-Ag85B for 2 weeks, the in vivo tumor fluorescence intensity in pVAX1-Ag85B group was significantly lower than that in the saline group (P <0.05). After 3 weeks, tumor fluorescence intensities in both pVAX1-Ag85A and pVAX1-Ag85B groups were significantly lower than that in the saline group (P < 0.01). But the efficacies of pVAX1-Ag85A and pVAX1-Ag85B groups were similar (P > 0.05). The distant lymphatic metastasis rate in pVAX1-Ag85B group was significantly lower than those in the saline (25.0% vs 87.5%) and pVAX1-Ag85A groups (25.0% vs 62.5%) (P <0.05). Conclusion: In vivo fluorescence image analysis system can dynamically, sensitively and visually evaluate the anti-tumor effects of DNA vaccines against bladder cancer cell-implanted tumors. Both pVAX1-Ag85A and pVAX1-Ag85B DNA vaccines have anti-tumor effects for bladder cancers.
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Objective To construct protective immunity to Mycobncterium tuberculosis latent infection, a novel fusion protein consisting of HspX, the 190 to 198 peptide of Mpt64 and Ag85B, which were confirmed to be the effective protective antigens mainly expressed in the dormancy and exponential phase of growth, was constructed and its immunogenicity was investigated. Methods Ag85B and Mpt64190-198-HspX sequences were amplified by PCR and cloned into plasmids pET-28a. The fusion protein, Ag85BMpt64190-198-HspX (AMH) was expressed in E. coli BL21 and purified with Ni-NTA resins. C57BL/6 mice were immunized three times at 2-week intervals subcutaneously with AMH formulated with the adjuvant composed of dimethyl-dioctyldecyl ammonium bromide (DDA) and BCG polysaccharide nucleic acid (BCGPSN). Humoral and cell-mediated immunity responses were analyzed at five weeks after the last injection. Results AMH was expressed stably in E. coli and could be purified well by Ni-NTA affinity chromatography. C57BL/6 mice immunized with AMH subunit vaccine generated specific cellular and humoral immunologic response to the stimulation of Ag85B, Mpt64190-198 and HspX. Conclusion It suggested that AMH was a promising candidate antigen of tuberculosis subunit vaccine.
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Eighty-five complex (85A, 85B and 85C), 35-kDa and superoxide dismutase (SOD) were cloned, expressed and purified as antigens in an enzyme-linked immunosorbent assay (ELISA) to compare the serological reactivity of cows with different shedding levels of Mycobacterium avium subsp. paratuberculosis (MPT). Antibody responses to all recombinant antigens positively increased depending on shedding levels. In particular, antibody responses to the 35 kDa were higher than those to the others in all shedder groups. Also, the mean of O. D. values among Ag 85 complex, 85B showed slightly higher response than others with high sensitivity and specificity in all shedder groups. In receiver operating characteristic (ROC) curve analysis, the result of 35 kDa ELISA yielded an area under the curve value of 0.945 (95% confidence interval = 0.895 . 0.996), which indicated that this 35 kDa is more accurate indicator of MPT infection than other antigens. At the cut-off point recommended by the ROC curve analysis, the sensitivity and specificity of 35 kDa ELISA were higher than those of other antigens with 93.3% and 86.4%, respectively. Finally, a commercially available ELISA kit was used to clarify 200 positive and 200 negative sera. We then re-tested these serum samples with our ELISA test using the 35-kDa antigens. 35 kDa ELISA and commercial kit showed almost similar results in ROC curve analysis even though two of positive sera in commercial kit were negative in 35 kDa ELISA. The sera, which showed difference in the comparison with commercial ELISA kit, they also did not react with 35 kDa in Western blot. These results suggest that a 35-kDa based ELISA can be useful for detecting MPT infection.
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Animals , Cattle , Antibodies, Bacterial/immunology , Antibody Formation/immunology , Antibody Specificity/immunology , Antigens, Bacterial/immunology , Blotting, Western , Cloning, Molecular , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay/veterinary , Molecular Weight , Mycobacterium avium subsp. paratuberculosis/immunology , Paratuberculosis/diagnosis , Protein Biosynthesis , Recombinant Fusion Proteins/immunology , Serologic TestsABSTRACT
BACKGROUND: IFN-gamma is the main effector mediator of the host immune response against Mycobacterium tuberculosis. Evaluating the IFN-gamma gene expression in response to M. tuberculosis antigens may help in elucidating the host defense mechanism against M. tuberculosis and in the development of a vaccine. METHODS: The IFN-gamma mRNA expression in the lymphocytes obtained from pleural effusions from tuberculous pleurisy patients (TB-PLC) after in vitro stimulation with whole cell M. tuberculosis(H37Rv), purified protein derivatives(PPD), man-lipoarabinamman (man-LAM), ara-LAM and Antigen 85B(Ag85B) were evaluated. The degree of IFN-gamma mRNA expression was determined by a semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. RESULTS: M. tuberculosis induced the expression of IFN-gamma mRNA in the TB-PLC in time and dose dependent manners. The PPD and Ag85B induced high levels of IFN-gamma mRNA expression in the TB-PLC. However, man-LAM inhibited IFN-gamma mRNA expression in the TB-PLC, while ara-LAM did not. CONCLUSION: IFN-gamma mRNA expression in TB-PLC is stimulated by PPD and Ag85B, but inhibited by man-LAM.
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Humans , Gene Expression , Interferon-gamma , Lymphocytes , Mycobacterium tuberculosis , Pleural Effusion , RNA, Messenger , Tuberculosis , Tuberculosis, PleuralABSTRACT
Objective:To investigate the immune efficacy after sequential immunization with Mycobacterium tuberculosis DNA vaccine encoding mature form of Ag85B(pTB30m)and Mycobacterium tuberculosis H37Ra in mice.Methods:Much of highly pure plasmid DNA(pTB30m)extracted by alkaline lysis method was confirmed by restriction endonuclease digestion.Then,its DNA concentration and purity were determined by UV spectrophotometry.At various intervals(4weeks,8weeks)after sequential immunization,ELISA was used to detect the level of the serum antibody against PPD.Also,the spleen lymphocytes of mice were cultured with PPD in vitro.Lymphocyte transformation was detected by MTT assay.Results:Prepared pTB30m was highly pure and came to the needed concentration.Compared with Group Naive control,the specific antibody levels against PPD and the stimulation index(SI)of spleen lymphocytes were all statistically higher in Group DNA-85B/H37Ra(P0.05),as compared with Group DNA-85B/BCG,Group H37Ra and Group BCG,However,compared with Group H37Ra and Group BCG,the SI of mice was significantly larger in Group DNA-85B/H37Ra(P
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Objective To study the anti-tumor effect of mycobacterium Ag85B/IL-2 fusion protein on syngenic mice bearing bladder cancer. Methods After being implanted BTT739 bladder transitional carcinoma cells from tumor bearing mice, 80 T739 mice were divided into Ag85B protein, BCG, IL-2 and normal saline groups (n=20). Mycobacterium Ag85B/IL-2 protein was locally injected to the mice at the site of implanting tumor in the trial group, and Ag85B protein, BCG, IL-2 and normal saline to the control group mice. The weight and volume of tumor and the survival period were recorded after treatment. Results The average weight of Ag85B/IL-2 fusion protein treatment group was significantly lower than those of Ag85B, BCG,IL-2 and normal saline group (P
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Objective:To construct an eukaryotic coexpression plasmid containing Mycobacterium tuberculosis Ag85B and MPT64 gene.Methods:Mycobacterium tuberculosis Ag85B and MPT64 gene were cloned into pBudCE4.1 to construct recombinant plasmid pBud85B-MPT.The recombinant plasmid was transfected into COS-7 cells,and its expression of Ag85B and MPT64 was assesed by RT-PCR.Results:Mycobacterium tuberculosis Ag85B and MPT64 were detected in transfected COS-7 cells.Conclusion:The recombinant plasmid pBud85B-MPT can express Ag85B and MPT simultaneously in COS-7 cells which provides the basis for further investigation of DNA vaccine against tuberculosis.