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Jun Dai,
Decui Pei,
Baoning Wang, Yu Kuang,
Laifeng Ren,
Kang Cao,
Bin Zuo,
Jingjing Shao,
Sha Li,
Zhonghua Jiang,
Mingyuan Li
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ABSTRACT: Secondary pneumonia due to Staphylococcus aureus (S. aureus) causes significant morbidity and mortality. The aim of the research was designed a novel DNA vaccine encoding the Mycobacterium tuberculosis secreted antigen Ag85A fused with the influenza A virus (IAV) HA2 protein to provide protection against both influenza and secondary infection with S. aureus. The DNA vaccine vector efficiently expressed the encoded antigen in mammalian cells, as determined by RT-PCR, Western blotting and immunofluorescence analysis. Mice were immunized with the vaccine by intramuscular injection before challenge with IAV and S. aureus. The pulmonary and the splenocyte culture IFN-gamma levels were significant higher in immunized mice than their respective controls. Although the antibody titer in the HI test was low, the sera of mice immunized with the novel vaccine vector were effective in neutralisation assay in vitro. The vaccine could reduce the loss of body weight in mice during IAV challenge. Both Western blotting and RT-PCR showed that the vaccine markedly enhanced toll like receptor 2 (TLR2) expression in splenocytes after the secondary infection with S. aureus. The survival rate of mice with high TLR2 expression (pEGFP/Ag85A-HA2 or iPR) was significantly increased compared with mice immunized with pEGFP/HA2 after challenge with S. aureus. However, the pulmonary IL-10 concentration and S. aureus titer were significantly decreased in immunized mice, and expression of TLR2 was increased after challenge with S. aureus. These results demonstrated that Ag85A could strengthen the immune response to IAV and S. aureus, and TLR2 was involved in the host response to S. aureus..
Virology Journal 01/2013; 10(1):40. · 2.34 Impact Factor
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ABSTRACT: Type 1 diabetes (T1D) is a chronic autoimmune disease caused by proinflammatory autoreactive T cells that mediate the selective destruction of insulin-producing β cells via both direct and indirect mechanisms. Many immune cells and proinflammatory cytokines are involved in the pathogenesis of autoimmune diabetes. Immune intervention is effective for the prevention and treatment of T1D by blocking the autoimmune assault to β cells. The non-structural protein 1(NS1) of influenza A viruses is a non-essential virulence factor encoded on segment 8 that has multiple accessory functions, including suppression of innate immunity and adaptive immunity, inhibition of apoptosis and activation of phosphoinositide 3-kinase (PI3K). This research investigated whether the expression of NS1 can prevent and treat diabetes mellitus induced by Streptozotocin (STZ). The NS1 expressing plasmid pEGFP-C2/NS1 was constructed and injected intramuscularly to both thighs of mice. Its effect on mice was observed. Intramuscular delivery of pEGFP-C2/NS1 resulted in reduction in hyperglycemia and diabetes incidence, with an increase in insulin. pEGFP-C2/NS1 could also increase glycogen and regulated serum cytokine levels. In addition, by comparison to the mice treated with empty vector pEGFP-C2, ameliorative insulitis was observed in the mice treated with recombinant plasmid pEGFP-C2/NS1. This result suggests that the expression of NS1 is effective for the prevention and treatment of diabetes mellitus induced by STZ in a mouse model.
Biochemical and Biophysical Research Communications 03/2012; 419(1):120-5. · 2.48 Impact Factor
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ABSTRACT: New approaches to improve the traditional gene carriers are still required. Here we explore Fe(3)O(4) modified with degradable polymers that enhances gene delivery and target delivery using permanent magnetic field. Two magnetic Fe(3)O(4) nanoparticles coated with chitosan (CTS) and polyethylene glycol (PEG) were synthesized by means of controlled chemical coprecipitation. Plasmid pEGFP was encapsulated as a reported gene. The ferriferous oxide complexes were approximately spherical; surface charge of CTS-Fe(3)O(4) and PEG-Fe(3)O(4) was about 20 mv and 0 mv, respectively. The controlled release of DNA from the CTS-Fe(3)O(4) nanoparticles was observed. Concurrently, a desired Fe(3)O(4) concentration of less than 2 mM was verified as safe by means of a cytotoxicity test in vitro. Presence of the permanent magnetic field significantly increased the transfection efficiency. Furthermore, the passive target property and safety of magnetic nanoparticles were also demonstrated in an in vivo test. The novel gene delivery system was proved to be an effective tool required for future target expression and gene therapy in vivo.
Journal of drug delivery. 01/2012; 2012:920764.
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Jun Dai,
Decui Pei,
Baoning Wang, Yu Kuang,
Laifeng Ren,
Kang Cao,
Huan Wang,
Bin Zuo,
Jingjing Shao,
Sha Li,
Hong Li,
Mingyuan Li
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ABSTRACT: A novel DNA vaccine vector encoding the Mycobacterium tuberculosis secreted antigen Ag85A fused with the influenza A virus (IAV) HA2 protein epitopes, pEGFP/Ag85A-sHA2 (pAg85A-sHA2), was designed to provide protection against influenza. The antigen encoded by the DNA vaccine vector was efficiently expressed in mammalian cells, as determined by reverse transcription polymerase chain reaction (RT-PCR) and fluorescence analyses. Mice were immunized with the vaccine vector by intramuscular injection before challenge with A/Puerto Rico/8/34 virus (PR8 virus). Sera and the splenocyte culture IFN-γ levels were significantly higher in immunized mice compared with the control mice. The novel vaccine group showed a high neutralization antibody titer in vitro. The novel vaccine vector also reduced the viral loads, increased the survival rates in mice after the PR8 virus challenge and reduced the alveolar inflammatory cell numbers. Sera IL-4 concentrations were significantly increased in mice immunized with the novel vaccine vector on Day 12 after challenge with the PR8 virus. These results demonstrated that short HA2 (sHA2) protein epitopes may provide protection against the PR8 virus and that Ag85A could strengthen the immune response to HA2 epitopes, thus, Ag85A may be developed as a new adjuvant for influenza vaccines.
Viruses 01/2012; 4(12):3606-3624. · 1.50 Impact Factor
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ABSTRACT: In order to develop a promising HCV gene vaccine candidate to induce effective immune response and explore the application of magnetic nanoparticles as gene delivery system.
The DNA fragment containing multi-epitope antigen gene of HCV with five conserved mimotopes was synthesized and cloned into plasmid pcDNA3.1 (+). The Fe3O4 modified with chitoson was prepared and the cytotoxicity of the magnetic material was detected in vitro. Analysis of recombinant plasmid in vitro expression, and its immunogenicity loaded by CTS-Fe3O4 in mice were evaluated in detail.
The HCV multi-epitope gene vaccine pcDNA3.1 (+)-MA was successfully constructed and recognized by 81% HCV positive sera. There was no cytotoxicity of CTS-Fe3O4 when its concentration was equal or less than 1 mmol/L. Both the antibody production and T-cell activity were induced.
It was believed that DNA encoding MA was an attractive approach for the therapeutic and prophylactic vaccines against HCV and the Fe3O4 modified with chitoson showed excellent target, safety and adjuvant effect as gene carrier.
Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 11/2011; 42(6):757-61, 788.
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ABSTRACT: In order to develop a promising vaccine candidate utilizing a combined approach to induce both antibody production and T-cell activity, the DNA fragment containing MA of HCV with five conserved epitopes was synthesized. Two types of HCV vaccine candidates (the DNA type and DNA/polymers) were constructed using MA. PLA-PEG-PLA and PLGA-PEG-PLGA were synthesized and used as micelles with encapsulated plasmid pcDNA3.1(+)-MA. The preparation of copolymers, the cloning and analysis of recombinant plasmid DNA, in vitro expression, and immunogenicity in transgenic mice were evaluated in detail. The results indicated that even single immunization and oral immunization with DNA/polymers achieved satisfying immune responses in vivo tests. As biodegradable and nontoxic triblock copolymers, the novel copolymers demonstrated a great advantage, as they made long-term and single-immunizing vaccines possible; in addition, the copolymers showed a better adjuvant effect and scarcely any side effects.
Comparative immunology, microbiology and infectious diseases 01/2011; 34(1):65-72. · 2.99 Impact Factor
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ABSTRACT: To construct the ureI and ctB-ureI eukaryotic expression plasmid with pIRES-RD2 and study the expressing characters of those plasmids in HEK 293.
We got the ureI and ctB-ureI gene from the procaryotic expression plasmid pET32a(+)-ureI and pET32a(+)-ctB-ureI by restriction enzyme BglII and XhoI, respectively.The pET32a(+)-ctB-ureI had been designed that ureI fused with Cholerae toxin B gene (ctB) at the 5'terminal of ureI to increase the immunogenicity of ureI, and then inserted those gens to eukaryotic expression plasmid pIRES-RD2 by ligase. After sequenced, the pIRES-RD2-ureI and pIRES-RD2-ctB-ureI were identical with the targets. These plasmids were transfected HEK293T cell strain by Lipofetmiane 2000. Then studied the transfection ratio of those cells by Fluorescence microscope, studied the expression features and the immunoreactivity of those cells by Immunofluorescence and Immunohistochemisty with the special antibodies.
Fluorescence microscope showed about 80% cells had been transfected the target plasmids, and Immunofluorescence and Immunohistochemisty demonstrated that the transfected cells expressed the recombinant proteins which located at the cytoplasm of HEK 293 strain after 48-72 hours. And the expressed products could react with the special antibodies, respectively.
We successfully constructed the ureI and ctB-ureI eukaryotic expression plasmid with pIRES-RD2, which were pIRES2-DsRed2-ureI and pIRES2-DsRed2-ctB/ureI. Both these two plasmids could express ureI or ctB-ureI in HEK 293 cell, and the expressed products had immunoreactivity, respectively.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 08/2010; 26(8):764-6.
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ABSTRACT: To observe the immune effect of Hap recombinant protein on murine model of bronchopneumonia infected with NTHi, and explore the mechanism about the anti-NTHi infection.
The C57BL/6 mice intranasally immunized with purified Hap recombinant protein and CT-B were challenged by NTHi encased in agar beads. The immunifaction of anti-infection was observed through encocyte counting of BALF, bacteria detection of lung and the pathologyical change of lung tissue.
In the challenge with NTHi experiment, the inflammatory exudation of the infected murine and pathological change of lung tissue was relieved by combined immunization of Hap recombinant protein and CT-B, and quantity of NTHi in lung of the infected murine was reduced obviously.
The Hap recombinant protein also had good ability of anti-NTHi infection in the murine model of NTHi bronchopneumonia. This study could offer the oretical and experimental basis for development of new vaccine against NTHi.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 07/2010; 26(7):635-7, 641.
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ABSTRACT: To study the anti-influenza A virus effects of traditional Chinese medicine Kanggan granules in chicken embryo and BALB/c mice.
The influenza A virus (H(1)N(1), FM1) was used in the experiments. FM1 was cultured in chicken embryo and the anti-FM1 activity of Kanggan granules was evaluated through the post-medication hemagglutination titer of FM1. In animal test, 120 healthy BALB/c mice were randomly divided into six groups, normal control, virus control, ribavirin, high-dosage, middle-dosage and low-dosage. The FM1 infection model was established by dripping FM1 into nasal cavity and then the appropriate treatments were prescribed. The effective anti- FM1 indices of Kanggan granules included survival status, protective percentage of death and life elongation percentage of mice infected with FM1.
The high and middle doses of Kanggan granules could inhibit the replication of FM1 remarkably in chicken embryo, and could reduced hemagglutination titer to 5 and 3 times. In animal experiments, all mice treated with Kanggan granules could improve the general status of infected mice, the protective percentages of death were 35.0% to 55.0%, the life elongation percentages were 73.0% to 88.9% and the minimal effective dose was 3.00 g/kg.
Kanggan granules can inhibit the replication of influenza A virus and protect the mice infected with FM1.
Zhonghua yi xue za zhi 07/2010; 90(26):1863-5.
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ABSTRACT: To express and purify Hap protein of nontypeable Haemophilus influenzae (NTHi) in prokaryotic system, and study its immunogenicity and adhesive activity.
Hap protein was expressed in E.coli BL21 with pET32a (+)-Hap and purified by affinity chromatography. The adhesive activity of the recombinant Hap protein was observed in competitive adhesion assay using scanning electron microscope and bacterial counting. BALB/C mice were immunized intranasally with the purified recombinant Hap protein and cholera toxin B subunit (CT-B), and anti-Hap IgA and IgG were detected by enzyme-linked immunosorbent assay.
SDS-PAGE analysis showed a single band of the target protein, whose purity reached 85% according to the result of Gel analysis software. The concentration of the protein was 3.2 g/L after ultrafiltration and condensation. Competitive adhesion assay showed that compared with control group, the recombinant Hap protein significantly inhibited the adhesion of NTHi to ECM (P<0.01). Compared with Hap immunization alone, immunization with Hap combined with CT-B resulted in significantly higher titers of anti-Hap IgG and IgA in mice (P<0.05).
Highly purified recombinant Hap protein has been obtained in a prokaryotic system and shows good immunogenic and adhesive activities. These results will establish the basis for further study of NTHi vaccine.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 05/2010; 30(5):953-6.
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ABSTRACT: This study was aimed to construct a prokaryotic expressing vector of Hap gene from Nontypeable Haemophilus influenzae, and express and identify the fusion proteins of Hap-His in E. coli. The gene encoding protein Hap was amplified from Nontypeable Haemophilus influenzae ATCC49247 chromosomal DNA by PCR, then it was cloned into prokaryotic expression plasmid pET-32a (+). The recombinant plasmid pET-32a(+)-Hap was transformed into E. coli BL21 and expression was induced by Isopropy-beta-D-thiogalatoside(IPTG). The Hap-His fusion protein expressed so was analyzed by SDS-PAGE and Western-blot. The results showed that the recombinant expressive plasmid pET-32a (+)-Hap was constructed successfully, and the recombinant plasmid expressed Hap-His fusion protein with relative molecule mass 176 000 and mainly existed in inclusion body. This fusion protein could combine with anti-His monoclonal antibody specifically through Western blot analysis. Successful expression of Hap-His fusion protein in prokaryotic cell could lay a basis for further study of immunocompetence of Hap protein and development of NTHi vaccine.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 10/2009; 26(5):1072-6.
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ABSTRACT: Influenza (flu) pandemics have presented a threat to human health in the past century. Because of outbreaks of avian flu in humans in some developing countries in recent years, humans are more eager to find a way to control flu. Mammalian beta-defensins (beta-defensins) are associated primarily with mucosal and skin innate immunity. Previous studies have demonstrated antimicrobial properties of a variety of defensin peptides. We have identified the presence of mouse beta-defensin 1, 2, and 3 genes (Mbd-1, 2, and 3) in trachea and lung tissues by RT-PCR before and after infection with influenza virus. We constructed a eukaryotic expression plasmid containing Mbd-3, pcDNA 3.1(+)/MBD-3, and the plasmid was introduced into Madin-Darby canine kidney (MDCK) cells by transfection. The expression of Mbd-3 in MDCK cells was verified by immunofluorescence test, RT-PCR, and Western blot. The pcDNA 3.1(+)/MBD-3 plasmid was injected into mice to observe its effect against influenza A virus (IAV) in vivo. Mouse beta-defensin genes could be expressed in trachea and lung tissues before IAV infection, but expression of Mbd-2 and Mbd-3 was increased significantly after IAV infection. The survival rate of mice with MBD-3 against IAV challenge was 71.43%, and MDCK cells with MBD-3 could clearly inhibit IAV replication. The results demonstrated that mouse beta-defensins possess anti-influenza virus activity, suggesting that mouse beta-defensins might be used as agents to prevent and treat influenza.
Archives of Virology 02/2009; 154(4):639-47. · 2.11 Impact Factor
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ABSTRACT: To construct the eukaryotic recombinant plasmid pcDNA3.1a(+)-M2e/CtB which contains H1N1 M2e gene and cholera toxin B subunit gene (CtB) and to study the expression and immunity of recombinant protein M2e/CTB in NIH3T3 cells.
M2e/CtB gene was cloned by PCR and digested with Hind III and Xho I. M2e/CtB was linked into pcDNA3.1a(+) to build eukaryotic expression plasmid pcDNA3.1a(+)-M2e/CtB. The pcDNA3.1a(+)-M2e/CtB was transfered into competent E.coli JM109. The transformed colonies were verified by Hind III and Xho I, PCR, and sequencing. The NIH3T3 cells were transfected with pcDNA3.1a(+)-M2e/CtB by positive ion polymer. The product of M2e/CtB gene with stable expression was analysed by immunofluorescence, RT-PCR sequencing, and Western blot.
The digested pcDNA3.1a (+)-M2e/CtB contains correct M2e and CtB gene. Blastn results showed the genetic homongenicity of M2e and CtB were 100%, respectively. The pcDNA3.1a(+)-M2e/CtB efficiently expressed M2e/CTB protein in the eukaryotic NIH3T3 cells. The cell lysis and supernant both contained the M2e/CTB protein, which had the immunity and reactivity to both anti-M2e and anti-CTB. The relative molecular mass of M2e/CTB protein was about 18 000 analysed by Western blot.
A new recombinant eukaryotic plasmid pcDNA3.1a(+)- M2e/CtB has been successfully constructed. The plasmid can express the fused protein of M2e with CTB. Our study will help further research into new and effective DNA vaccines against influenza virus A.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 04/2008; 24(3):263-6.
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ABSTRACT: To optimize the isolation and purification conditions for Hap(s) protein of non-typeable Haemophilus influenzae.
Hap(s) protein was purified by ammonium sulfate precipitation, dialysis desalting and Hitrap weak cation exchange columns of CM Sepharose Fast Flow. The condition of the elution was optimized for pH and ionic strength, the absorbance at 280 nm of the elution samples were detected, and the targeted protein band in the collected samples was observed by SDS-PAGE electrophoresis.
The Hitrap ion exchange column was eluted with buffer 1, which resulted in a baseline distribution of absorbance at 280 nm. Buffer 2 elution of the column resulted in the presence of peak absorbance with trails, which was identified to be constituted by some low molecular weight bands by subsequent SDS-PAGE. In serial column elution with buffer 3 with different ionic strength, a peak absorbance was observed with the ionic strength of 100 mmol/L NaCl, and SDS-PAGE confirmed that the peak was generated by the target protein. No obvious peaks or bands in SDS-PAGE occurred with the other ionic strengths.
The pH of the buffer only affect the elution of the irrelevant proteins rather than the Hap(s) protein, and elution with the buffer containing 100 mmol/L NaCl can be optimal for eluting the Hap(s) protein.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 01/2008; 27(12):1880-3.
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ABSTRACT: To prepare and characterize the monoclonal antibody (mAb) against human SOCS3.
BALB/c mice were immunized with recombinant GST-SOCS3 protein, from which the spleen cells were isolated and fused with Sp2/0 cells. After several rounds of screening and cloning, the hybridoma cell strain secreting anti-SOCS3 mAb was obtained, whose specificity was evaluated using ELISA and Western blotting, and the titer, immunoglobulin subtype and affinity of the mAb were also measured.
The hybridoma cell strain secreting anti-SOCS3 mAb was identified to belong to IgG2a subtype. The mAb titers in cultural supernatant and acetic fluid were 1:640 and 1:25600, respectively, as determined by ELISA with affinity reaching 4.84x10(6) L/mol.
The success in anti-SOCS3 mAb preparation provides the basis for further study of the negative regulation of cytokine signal transduction and the immunoregulation in microorganism infections.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 12/2007; 27(11):1778-80.
