[Sensitivity Comparison Experiment of Four Testing Methods for Helicobacter pylori].

Objective: To measure with standard microbiology methods the sensitivity of 4 commonly used testing methods for Helicobacter pylori (Hp) and to conduct a comparative study of the correlations and differences across the 4 methods. Methods: With the Hp standard strain (SS1) as the reference, colony forming units (CFU) as the units of quantitative analysis for detection performance, and gradient dilution of SS1 suspension as the simulation sample, we measured the sensitivity of 4 Hp testing methods, including bacterial culture, rapid urease test, antigen test, and quantitative fluorescent PCR. CFU values at different concentrations corresponding to the 4 commonly used Hp testing methods were documented and the correlations and differences were analyzed accordingly. Results: The sensitivity of Hp bacterial culture, rapid urease test, antigen test and quantitative fluorescent PCR was 2.0×10 CFU/mL, 2.0×10 5 CFU/mL, 2.0×10 5 CFU/mL, and 2.0×10 2 CFU/mL, respectively. Conclusion: The testing turnover time and sensitivity of different laboratory methods for Hp testing varied significantly. The quantitative fluorescent PCR and bacterial culture both showed relatively high sensitivity, but bacterial culture has complicated operation procedures and is too time-consuming. The rapid urease test and antigen test both were simple and quick to perform, but showed low sensitivity. For clinical and laboratory testing of Hp, appropriate testing method that can identify the corresponding changes of Hp should be selected according to the actual testing purpose.

[Preparation and Release Properties of Helicobacter pylori Recombinant Protein PLGA Microspheres and PLGA-Chitosan Microspheres].

OBJECTIVE: To preparethe poly lactic-co-glycolic acid (PLGA) microspheres and PLGA-chitosan microspheres containing Helicobacter pylori recombinant protein, namely the BIB protein, and to explore their optimal preparation parameters and in vitro release performance in gastric and intestinal fluids. METHODS: Double emulsions (water-in-oil-in-water, or W1/O/W2) solvent evaporation method was used to prepare the BIB-PLGA microspheres and the BIB-PLGA-chitosan microspheres. Univariate analysis was done to study the impact of the water-to-oil ratio (W1/O), PLGA mass fraction and PVA concentration on the morphology, particle size, polydispersity index (PDI), encapsulation efficiency (EE), and drug loading (DL) so as to identify the optimal parameters. Bicinchoninic acid (BCA) assay was used to determine the protein concentration and the release efficiency of BIB. RESULTS: The optimal preparation parameters identified in the study were as follows: W1/O at 1∶2, PLGA mass fraction at 5%, and PVA mass fraction at 0.2%. The BIB-PLGA microspheres were found to be (2.11±0.08) µm in particle size, 0.35±0.18 in PDI, (78.20±1.73)% in EE and (10.58±0.23)% in DL. The BIB-PLGA-chitosan microspheres were (2.28±0.52) µm in particle size, 0.39±0.54 in PDI, and (78.87±1.30)% and (15.50±0.25)% in EE and DL, respectively. Both BIB-PLGA microspheres and BIB-PLGA-chitosan microspheres showed slow-release property in gastric and intestinal fluids in vitro, with BIB-PLGA-chitosan microspheres showing better slow-release performance. CONCLUSION: The BIB-PLGA microspheres and BIB-PLGA-chitosan microspheres prepared with the double emulsions solvent evaporation method showed high DL and EE, controllable particle sizes, dispersive appearance, and slow-release property in gastric and intestinal fluids in vitro.

Anti-bacterial and anti-viral effects of Fengreqing oral liquid () in vitro and in vivo.

OBJECTIVE: To investigate the anti-bacterial and anti-viral effects of Fengreqing oral liquid (, FRQ) in vitro and in vivo. METHODS: The minimum inhibitory concentrations of Fengreqing Oral Liquid against six gram-positive bacteria (Staphylococcus aureus, Streptococcus mutans, Peptostreptococcus anaerobius, Hemolytic streptococcus, Streptococcus pneumoniae, Klebsiella pneumoniae), seven gram-negative bacteria (Escherichia coli, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Haemophilus influenzae, Helicobacter pylori, Pseudomonas aeruginosa, Gardnerella vaginalis) and Candida albicans were detected by the paper disc diffusion method. The inhibition rate of A/PuertoRico/8/34(H1N1) (PR8) influenza virus in different concentrations of Fengreqing oral solution was detected by chicken embryo method. CCK8 method was used to detect the half-cell infection of RSV, VSV and CVB3. The effect of FRQ on the survival curve of mice was detected by using co-infection model of Streptococcus pneumoniae and influenza virus. RESULTS: In vitro, FRQ can inhibit Actinobacillus actinomycetemcomitans, Helicobacter pylori, Gardnerella vaginalis, Staphylococcus aureus, Streptococcus mutans and Streptococcus pneumoniae and has an antiviral effect on the envelope virus H1N1. In vivo, Fengreqing oral solution had therapeutic effect on influenza-Streptococcus pneumoniae co-infection in mice, significantly improving the survival rate of mice. The medium dose and low dose FRQ significantly prolonged the survival time of mice. CONCLUSION: FRQ has good anti-bacterial and anti-viral effectsin vivo and in vitro.

Epidemiology of norovirus gastroenteritis in hospitalized children under five years old in western China, 2015-2019.

OBJECTIVES: Norovirus is associated with one-fifth of all gastroenteritis cases, but basic epidemiological data is lacking, especially in developing countries. As long-term surveillance on norovirus gastroenteritis is scarce in western China, this study aims to update the epidemiological knowledge of norovirus gastroenteritis and to characterize the genotypes of norovirus strains. METHODS: Stool samples were collected from hospitalized children under 5 years old with gastroenteritis in Chengdu, China. All samples were tested for norovirus as well as rotavirus, sapovirus, enteric adenovirus, and astrovirus by real-time RT-PCR. RdRp and VP1 genes were sequenced in norovirus-positive samples to investigate viral phylogenies. RESULTS: Of the 1181 samples collected from 2015 to 2019, 242 (20.5%) were positive for norovirus. Among norovirus-positive cases, 65 cases had co-infection with another virus; norovirus/enteric adenovirus was most frequently detected (50.8%, 33/65). The highest positive rate was observed in children aged 13-18 months (23.7%, 68/287). Norovirus infection peaked in autumn (36.6%, 91/249), followed by summer (20.3%, 70/345). Pearson correlation analysis showed significant correlation between the norovirus-positive rate and humidity (r = 0.773, P < 0.05). GII.4 Sydney 2012 [P31] (48.5%, 79/163) and GII.3 [P12] (35.6%, 58/163) were the dominant norovirus strains. CONCLUSIONS: Norovirus has become one of the most common causes of viral gastroenteritis in children under 5 years old in western China. Continuous monitoring is imperative for predicting the emergence of new epidemic strains and for current vaccine development.

[Monoclonal Antibody Against N Terminal 439-451 Epitopes of Anti-Mullerian Hormone and Its Properties].

OBJECTIVE: To prepare the specific monoclonal antibody against the N-terminal specific epitope peptide of anti-mullerian hormone (AMH) and to identify its specificity. METHODS: Using bioinformatics analysis software to predict the specific peptide fragment of AMH. Then synthesized four antigenic epitope peptide segments of mature N-terminal region of AMH as the screening target antigen. Synthesized AMH wholegene.Using the prokaryotic expression system to abtain recombinant AMH protein. Immunized BALB/c mice with the recombinant AMH, and prepared mouse spleen cells for fusing with SP/20 cells. Preparation of AMH monoclonal antibody by hybridoma technology. The monoclonal antibodies against AMH were screened by using four N-terminal epitope peptides (1: 439-451 RGRDPRGPGRAQ, 2: 273-285 PPRPSAELEESPP, 3: 42-54 DLDWPPGSPQEPL, 4: 494-506 WPQSDRNPRYGNH) as antigens, and indirect ELISA and Western blot were used to identify the antigen binding characteristics of the selected monoclonal antibodies. RESULTS: Two hybridoma cell lines with stable anti-AMH-1 and anti-AMH-2 antibody activities were screened. The two antibodies were named anti-AMH-1 and anti-AMH-2 respectively. The antibody titers were 1∶12 000 and 1∶1 600 after purification. Western blot confirmed that the two McAbs recognized different antigens. Anti-AMH-1 could not only recognize the N-terminal 439-451 epitope peptide of AMH, but also recognize the amino acid sequence of recombinant AMH, as well as the ovarian tissue. Anti-AMH-2 could recognize recombinant AMH and ovarian tissue. CONCLUSION: Two monoclonal antibodies against N-terminal specific epitopes of human AMH were successfully constructed.

Adenovirus-Mediated CRM197 Sensitizes Human Glioma Cells to Gemcitabine by the Mitochondrial Pathway.

PURPOSE: The cross-reacting material 197 (CRM197) is a mutation of the diphtheria toxin. The protein of CRM197 was used successfully for the therapy of various tumors in the recent studies. In this study, the recombinant adenoviruses containing the CRM197gene(AdCRM197) were used to enhance the cellar toxicity of gemcitabine in human glioma U87, U251, and H4 cells. PROCEDURES: MTT assay and flow cytometric analysis were performed to test the apoptosis of the U87, U251 and H4 cells with the combined treatment of AdCRM197 plus gemcitabine. Western blotting analyses were carried out to detect the cell apoptosis of the mitochondrial pathway. And the xenograft nude mice were used to observe the enhanced antitumor effect of AdCRM197 in vivo. RESULTS: AdCRM197 sensitizes human glioma cells to gemcitabine in vitro by the mitochondrial pathway. Tumor volume was inhibited and survival time was prolonged in the U251 or U87 xenografted nude mice with gemcitabine plus AdCRM197. The enhanced antitumor effect of AdCRM197 was also detected by the immunohistochemical analyses and TUNEL staining. CONCLUSION: The authors found that AdCRM197 sensitized the human glioma to gemcitabine not only in vitro but also in vivo. They provide the first evidence that adenovirus-mediated CRM197 may be a potential chemosensitizing agent for the treatment of cancer. The diphtheria toxin is of great toxicity that even one molecule of diphtheria toxin is enough to kill one cell. However, because of the high toxicity, the diphtheria toxin would kill the packing cells when it is being packaged into the recombinant viruses. Therefore, the diphtheria toxin is hard to be used in the gene therapy for virus vectors. The cross-reacting material 197 (CRM197) is a mutation of the diphtheria toxin. Unlike DTA, CRM197 exhibit a weak toxicity. The week toxicity of CRM197 is a good feature for the virus packaging. In the present study, we used a recombinant adenovirus which carried a CRM197 gene (AdCRM197) to enhance the cellar toxicity of gemcitabine in human glioma cells.

Efficacy and Safety of Opioids for the Prevention of Etomidate-Induced Myoclonus: A Meta-Analysis.

Etomidate is a widely used hypnotic drug for induction of general anesthesia and sedation, especially in elderly patients and hemodynamically unstable patients. Myoclonus, however, is the most prominent problem during induction of anesthesia with etomidate. Many agents have been used to prevent it and opioid is one of them. This meta-analysis was to evaluate effects of opioids pretreatment for preventing etomidate-induced myoclonus. We searched the PubMed, EMBASE, and the Cochrane Library databases and published studies in English updated to September 2015. Randomized controlled trials of opioids versus placebo/control in patients were included. We evaluated the prophylactic effect of opioids on etomidate-induced myoclonus. All statistical analysis was performed using RevMan 5.2 software. Nine randomized controlled trials involving 604 participants were included. The results indicated that compared with placebo/control, opioids allow more patients to experience no myoclonic movements after etomidate injection [risk ratio (RR) 2.76, 95% confidence interval (CI) 1.75-4.37, P < 0.0001]. The numbers of patients with mild myoclonus [(RR) 0.53, 95% (CI) 0.36-0.78, P = 0.001], moderate myoclonus [(RR) 0.36, 95% (CI) 0.23-0.55, P < 0.00001], and severe myoclonus [(RR) 0.20, 95% (CI) 0.08-0.52, P = 0.0009] after etomidate injection were significantly decreased with the pretreatment of opioids. This meta-analysis suggests that pretreatment with opioids before injecting etomidate was effective for preventing etomidate-induced myoclonus and can reduce the intensity of myoclonus without any adverse effects.

Inhibition of antiviral drug cidofovir on proliferation of human papillomavirus-infected cervical cancer cells.

In order to evaluate the potential application value of cidofovir (CDV) in the prevention of human papillomavirus (HPV) infection and treatment of cervical cancer, the inhibitory effect of CDV on the proliferation of HPV 18-positive HeLa cells in cervical cancer was preliminarily investigated, using cisplatin (DDP) as a positive control. An MTT assay was used to analyze the effects of CDV and DDP on HeLa cell proliferation. In addition, clone formation assay and Giemsa staining were used to examine the extent of HeLa cell apoptosis caused by CDV and DDP. Flow cytometry was also used to detect the shape and size of apoptotic cells following propidium iodide staining, while western blot analysis identified the expression levels of of E6 and p53 proteins in HeLa cells. A cell climbing immunofluorescence technique was used to locate the subcellular position of p53 in HeLa cells. The results demonstrated that CDV and DDP inhibited the proliferation of HeLa cells in a concentration- and time-dependent manner. Flow cytometry showed that CDV and DDP treatments resulted in cell arrest in the S-phase, and triggered programmed cell death. Furthermore, western blot analysis revealed that CDV and DDP inhibited E6 protein expression and activated p53 expression in HeLa cells. Finally, the immunofluorescence results indicated that CDV and DDP inhibited the nuclear export of p53 by E6 protein, which is required for degradation of endogenous p53 by MDM2 and human papilloma virus E6. In conclusion, CDV and DDP inhibited HeLa cell proliferation in a concentration- and time-dependent manner, reduced the expression of E6 protein, and reinstated p53 protein activity. Thus, CDV regulates cell cycle arrest and apoptosis, and may be a potential cervical cancer therapeutic strategy.

[The New Bacteria Expressing Recombinant Multi-epitope Vaccine against Helicobacter pylori and Its Microbiological Characteristics].

OJECTIVE: To construct the engineering bacteria with recombinant plasmid expressing the multi-epitope vaccine which composed of Helicobacter pylori urea membrane channel protein (UreI), Helicobacter pylori urease B subunit (UreB) and cholera toxin B subunit (CTB), and then to study it's microbiological characteristics. METHODS: The sequence contains some dominant epitopes of Helicobacter pylori UreI and UreB was designed, and ctB was added at the N-terminal, all the sequence were linked by flexible linkers. Codon optimization was done according to Escherichia coli (E. coli) BL21 (DE3) bias, the optimized sequence was designated BIB. BIB sequence was synthesized and cloned into plasmid pET28a(+). The recombinant plasmid was confirmed by restriction enzyme digestion and DNA sequencing. The recombinant protein BIB was expressed in E. coli BL21 (DE3) and analyzed by Western blot. RESULTS: The plasmid of pET28a(+)/BIB was constructed successfully, confirmed by restriction enzyme digestion and DNA sequencing. The recombinant protein BIB with relative molecular mass about 33 x 10(3) could be produced by E. coli BL21 (DE3) and was detected by Western blot. The relative molecular mass and N-terminal amino acid sequence of BIB were 100% identity with the design. CONCLUTION: The engineering bacteria with recombinant plasmid expressing the multi-epitope vaccine against Helicobacter pylori was constructed successfully. The recombinant protein BIB can be identified by anti-Sydney strain 1 of Helicobacter pylori (H. pylori SS1) polyclonal antibody and anti-CTB monoclonal antibody, which demonstrated that BIB has the expected antigenicity.

Protection against Helicobacter pylori infection in BALB/c mice by oral administration of multi-epitope vaccine of CTB-UreI-UreB.

Chronic gastric infection by the Gram-negative bacterium Helicobacter pylori (H. pylori) is strongly associated with gastritis, gastric ulcer and the development of distal gastric carcinoma and gastric mucosal lymphoma in humans. Antibiotic treatment of H. pylori is becoming less effective because of increasing antibiotic resistance; other treatment approaches such as specifically targeted methods, etc. to destroy this organism would be beneficial. An epitope vaccine is a promising option for protection against H. pylori infection. In this study, a multi-epitope vaccine was constructed by linking cholera toxin B subunit (CTB), two antigenic fragments of H. pylori urease I subunit (UreI20-29, UreI98-107) and four antigenic fragments of H. pylori urease B subunit (UreB12-23, UreB229-251, UreB327-400, UreB515-561), resulting in the recombinant CTB-UreI-UreB (BIB). Its protective effect against H. pylori infection was evaluated in BALB/c mice. Significant protection against H. pylori challenge was achieved in BALB/c mice immunized with BIB (15/18, 83.3%), rIB plus rCTB (6/18, 33.3%) and rIB (2/18, 11.1%) separately, while no protective effect was found in the mice immunized with either adjuvant rCTB alone or PBS. The induction of significant protection against H. pylori is possibly mediated by specific serum IgA and mucosal sIgA antibodies, and a mixed Th1/Th2/Th17 cells response. This multi-epitope vaccine might be a promising vaccine candidate that helps to control H. pylori infection.

Nutlin-3-induced redistribution of chromatin-bound IFI16 in human hepatocellular carcinoma cells in vitro is associated with p53 activation.

AIM: Interferon-γ inducible protein 16 (IFI16), a DNA sensor for DNA double-strand break (DSB), is expressed in most human hepatocellular carcinoma cell (HCC) lines. In this study we investigated the re-localization of chromatin-bound IFI16 by Nutlin-3, a DNA damage agent, in HCC cells in vitro, and the potential mechanisms. METHODS: Human HCC SMMC-7721 (wild-type TP53), Huh-7 (mutant TP53), Hep3B (null TP53) and normal fetal liver L02 cell lines were examined. DSB damage in HCC cells was detected via γH2AX expression and foci formation assay. The expression of IFI16 and IFNB mRNA was measured using RT-PCR, and subcellular localization and expression of the IFI16 protein were detected using chromatin fractionation, Western blot analysis, and fluorescence microscopy. RESULTS: Treatment of SMMC-7721 cells with Nutlin-3 (10 µmol/L) or etoposide (40 µmol/L) induced significant DSB damage. In SMMC-7721 cells, Nutlin-3 significantly increased the expression levels of IFI16 and IFNB mRNA, and partially redistributed chromatin-bound IFI16 protein to the cytoplasm. These effects were blocked by pretreatment with pifithrin-α, a p53 inhibitor. Furthermore, Nutlin-3 did not induce ectopic expression of IFI16 protein in Huh-7 and Hep3B cells. Moreover, the association of IFI16 with chromatin and Nutlin-3-induced changes in localization were not detected in L02 cells. CONCLUSION: Nutlin-3 regulates the subcellular localization of IFI16 in HCC cells in vitro in a p53-dependent manner.

[The research on the construction and characteristics of recombinant engineering bacteria with multi-epitope of Helicobacter pylori].

OBJECTIVE: To construct the multi epitope prokaryotic expression plasmid and appropriate engineering bacteria expressing the multi-epitope fusion protein of urea membrane channel protein (UreI), urease B subunit (UreB) and adhesin (HpaA) of Helicobacter pylori, then study its microbiological characteristics. METHODS: The target sequence contains multi epitope gene sequence of Helicobacter pylori were designed and synthesized, subsequently; it was subcloned into the expression vector pET28a (+), confirmed by restriction enzyme digestion and DNA sequencing. The fusion protein rIBA was expressed in E. coli Rosseta (DE3) and analyzed by Western blot. RESULTS: The plasmid of pET28a(+)/IBA was constructed successfully, confirmed by endonuclease digestion and sequence analyze. The expressed rIBA protein with relative molecular mass about 40 x 10(3) and can be detected by Western blot. CONCLUSION: The prokaryotic engineering bacteria expression multi-epitope of the Helicobacter pylori was constructed successfully. The recombinant protein rIBA expressed by the engineering bacteria can be identified by Sydney strain 1 of Helicobacter pylori (H. pylori SS1) specific antibody IgY, which demonstrated that the rIBA has high correlation with H. pylori SS1.

Noxa enhances the cytotoxic effect of gemcitabine in human ovarian cancer cells.

Noxa is an important proapoptotic protein in the intrinsic pathway of cell apoptosis. Experiments were carried out to investigate whether Noxa could, therefore, enhance the cytotoxic effect of gemcitabine in human ovarian cancer cell lines (A2780 and COC1). In this study, the combined treatment of Noxa and gemcitabine, in vitro, significantly inhibited the proliferation of A2780 and COC1 cells, as verified by MTT assay, Hoechst staining, and flow cytometric analysis. Moreover, the combination of Noxa and gemcitabine inhibited tumor growth and prolonged the survival of nude mice in vivo. The combined treatment also inhibited the growth of tumor xenografts through the inhibition of proliferation and the induction of apoptosis, as observed in immunohistochemical anti-PCNA staining and TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Our data suggest that Noxa exhibited potent proapoptotic activity against human ovarian cancer cells, and the combination of Noxa and gemcitabine showed a more significant cytotoxic effect against ovarian cancer cells in comparison with either of these agents alone. To our knowledge, we have provided the first evidence that Noxa can enhance therapeutic responses of ovarian cancer cells to gemcitabine, and that it could be potentially useful as a chemosensitizer in ovarian cancer therapy.

[Investigation of HCV multi-epitope gene vaccine loaded by CTS-Fe3O4].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Study on the anti-NTHi infection of Hap recombinant protein in vivo].

AIM: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Construction eukaryotic plasmids of the ureI and ctB-ureI and profile its' expression in cell].

AIM: To construct the ureI and ctB-ureI eukaryotic expression plasmid with pIRES-RD2 and study the expressing characters of those plasmids in HEK 293. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Construction and expression characteristics in vitro of human papillomavirus type 16 E7 suicidal DNA vaccine].

OBJECTIVE: To construct the suicidal DNA vaccine of human papillomavirus type 16 E7 gene (HPV16), and explore the DNA vaccine expression characteristics in vitro and capacity of inducing the transfected cells into apoptosis. METHODS: HPV16 E7 gene cloned by PCR from pET32/E7 was inserted into the plasmid pSCA1 to construct the recombinant plasmid pSCA/E7, followed by identification with PCR, BamH I and Sma I digestion and sequencing. pSCA/E7 was then used to transfect BHK-21 cell line. The transient expression of HPV16 E7 gene was confirmed by immuno-fluorescent staining, and the apoptosis induced by pSCA/E7 was checked with TDT-mediated dUTP nick end-labeling (TUNEL). RESULTS: The cloned E7 gene fragment was about 400 bp in length. PCR, restriction endonuclease digestion and sequence analysis revealed that the HPV16 E7 gene was cloned into the eukaryotic expression plasmid pSCA1 successfully. Immunofluorescent staining confirmed that the E7 gene could express in BHK-21 cell line. The BHK-21 cells transfected with pSCA/E7 could be induced into apoptosis which was confirmed by TUNEL. CONCLUSION: The results show that HPV16 E7 suicidal DNA vaccine can express in BHK-21 cell line, and induce the pSCA/E7 transfected cells into apoptosis. These findings may provide the foundation for exploring the therapeutic vaccine against HPV16-associated cervical cancer.

[Cloning of ureI gene from Helicobacter pylori and its expression in E. coli].

OBJECTIVE: To clone the urea membrane channel gene (ureI) from Helicobacter pylori (Hp) for its expression in E. coli, and evaluate the expression conditions and immunological features of the fusion protein. METHODS: ureI gene cloned by PCR from Hp was inserted into the plasmid pET32a (+) to construct the recombinant plasmid pET32a/ureI, followed by identification by BglII and HindIII digestion and sequencing. E. coli BL-21+(DE3) was transformed with pET32a/ureI to obtain the engineered bacterium BL21+/UreI, which was cultured at different temperatures and induced with 1.0 mmol/L IPTG for expression of the recombinant protein. The expressed proteins were identified by SDS-PAGE and analyzed by Pro-gel analyzer 4.0. Western blotting was performed to evaluate the immunogenicity of the expressed protein. RESULTS: The cloned gene fragment was about 650 bp in length, and BglII and HindIII digestion of pET32a/ureI yielded a 650-bp band. Sequence analysis revealed that the cloned ureI gene contained 646 bp without reading frame alterations. Comparison against GenBank indicated a homology of 100% of the cloned gene with ureI gene of the corresponding Hp strains, and also one no less than 98.5% with ureI gene from other strains. The engineered E. coli BL21+/UreI could express recombinant UreI (rUreI) with His tag, and the target protein accounted for 20.2% of the total bacterial proteins after 1.0 mmol/L IPTG induction of the bacterium at 37 degrees C for 14 h. SDS-PAGE and Western blotting showed that the recombinant UreI protein was produced mainly in the inclusion bodies and fused with his-tag (rUreI/his), which could react with human anti-Hp and mAb to his tag but not with mAb to Hp UreB. CONCLUSIONS: We have successfully cloned ureI gene and constructed the prokaryotic expression plasmid for efficient rUreI expression, and the fusion protein rUreI/his expressed in the inclusion bodies can react specifically with both Hp antibody and his-tag antibody.

[Analysis of protein expression feature and construction of procaryotic expression system for human papillomavirus type 16 (HPV-16) E4 gene].

OBJECTIVE: To clone the E4 gene (E4) from human papillomavirus type 16(HPV-16), construct the engineering bacteria of prokaryotic expression, and explore the expression conditions and the characters of expression product. METHODS: The complete E4 gene was cloned by PCR from the sample cell extract of clinical cervical disease that was the positive HPV-16 confirmed by Real-PCR. The E4 DNA fragment was inserted into the pET32a(+) to construct a prokaryotic expression plasmid, called as pET32/E4. Then the expression plasmids were transferred into competent E. coli BL21 (DE3). Recombinant DNA was identified by Bgl II and Hind III digestion, and then sequencing. The recombine bacterium, BL21/E4, was induced with different IPTG concentrations at different temperatures. The expressed proteins were checked and analyzed by SDS-PAGE and Gel-Pro Analyzer 4. His-tag of BL21/E4 expression protein was hybridized to McAb. RESULTS: The E4 gene cloned by PCR was about 342 bp. The blasted result showed that the E4 gene had 99% homology of HVP-16 DNA sequence, the cloned E4 gene expression frame was the same as HVP-16 East Asia strain's. Compared with other HPV-16 strains in GenBank, the homology of E4 gene was above 97%. pET32/E4 could express recombinant E4 (rE4) in BL21. The highest expression, which was 12.2% or 12.8% of total bacterial proteins respectively, was gotten when BL21/E4 was induced by 0.1 mmol/L IPTG at 28 degrees C or 37 degrees C for 18 hours. The results of SDS-PAGE and Western blot showed the rE4 was expressed mainly to form the inclusion body, and to fuse with his-tag (rE4/His), that was soluble and had a molecular weight as about 34 KDa. CONCLUSION: We cloned successfully the E4 gene from HPV-16 and constructed the prokaryotic expression E. coli BL21/E4, which could expression rE4 protein fused with his-tag (rE4/His), effectively. The fused protein could react to McAb recognizing His-tag, which was convenience purified by affinity chromatography. The above research results built a good foundation for preparing the high grade of purity E4 protein and developing the relative study.

[Construction of eukaryotic expressing plasmids for HA and HA1 of influenza A virus and their transient expression in HEK293 cells].

OBJECTIVE: To construct influenza A virus (A/PR/8/34) HA and HA1 eukaryotic expressing plasmids and study their expression in HEK293 cells. METHODS: HA and HA1 genes were cloned by RT-PCR and then inserted into pcDNA3. 1 (+). After identification of restriction enzyme digestion, PCR and sequencing analysis, HA and HA1 eukaryotic expressing plasmids were transfected into HEK293 cells with PolyFect Transfection Reagent. Immunofluorescence assay was used to observe the transient expressing result. RESULTS: It was confirmed that the construction of HA and HA1 eukaryotic expressing plasmids was made successfully. The stronger fluorescence signals were detected in transfected HEK293 cells with these two kinds of plasmids by immunofluorescence assay. CONCLUSION: The experiment is a success in the construction of eukaryotic expressing plasmids for HA and HA1, thus providing a basis for further probing into the mechanism of virus infection and exploring DNA vaccine.