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Objective:To develop a recombinant protein vaccine based on KPC-2, a drug resistance target in Klebsiella pneumoniae, and evaluate its immunogenicity, protective efficacy and mechanism in a mouse model of pneumonia. Methods:KPC-2 was expressed in Escherichia coli and purified using GST affinity chromatography. A recombinant protein vaccine was prepared with KPC-2 and used to immunize New Zealand rabbits through subcutaneous injection. Serum samples were isolated from cardiac blood and Protein G chromatography was used to purify polyclonal antibodies against KPC-2. Opsonophagocytic killing assay was used to assess the bactericidal activity of the polyclonal antibodies in vitro. Female BALB/c mice were immunized three times with the recombinant protein vaccine, and the titers of specific IgG antibodies in serum were measured by indirect ELISA. One week after the last vaccination, the mice were infected with Klebsiella pneumoniae strain SRT through tracheal intubation, and received a single intravenous dose of meropenem (0.1 mg) 1 h later. The protective efficacy of the KPC-2 recombinant protein vaccine was evaluated by comparing the survival rates, bacterial colonization and histopathological changes between vaccine group and adjuvant group as well as the survival rates between meropenem group and normal saline group. Moreover, the protective efficacy of polyclonal antibodies against KPC-2 was evaluated through passive immunization. Results:The level of specific IgG antibodies in serum was significantly higher in the vaccine group than in the adjuvant group ( t=4.325, P<0.05). The survival rate in the vaccine group was also higher than that of the adjuvant group [70% (7/10) vs 10% (1/10), P<0.05]. Furthermore, lung inflammation was less severe and bacterial burden was reduced in the vaccine group as compared with those of the control group ( t=3.127, P<0.05). Both active and passive vaccination strategies demonstrated strong protective efficacy against Klebsiella pneumoniae infection, and had a synergistic effect when used in combination with antibiotic therapy. The polyclonal antibodies against KPC-2 had bactericidal activity in vitro ( t=5.427, P<0.05). Conclusions:The prepared KPC-2 vaccine has better immunogenicity and protective efficacy. It can induce strong humoral immune responses. This study suggest that drug resistance target may be used as a candidate antigen for future vaccine development.

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Objective:To evaluate the impact of three small compounds, namely sodium diethyldithiocarbamate (DTC), levamisole (LMS) and imiquimod (Imi), on the immunogenicity and protective efficacy of the candidate antigen PA0833 from Pseudomonas aeruginosa ( Pa) and analyze the underlying mechanisms. Methods:PA0833 was formulated with aluminum adjuvant and the above small compounds, respectively. BALB/c mice were immunized with these vaccines intramuscularly on days 0, 14 and 21. Serum samples were collected and the levels of PA0833-specific IgG were measured by ELISA. The protective efficacy of these vaccines was evaluated by assessment of survival rates, body weights, clinical scores, inflammatory factors, and histopathological changes after infecting the immunized mice with Pa PAO1 strains. Besides, the mice were injected with DTC intramuscularly for seven consecutive days to analyze the mechanism of DTC in enhancing immune response using transcriptome sequencing and flow cytometry. Results:All these small compounds were capable of effectively enhancing the immunogenicity of PA0833 formulated with aluminum adjuvant, reducing bacterial loads in lung tissues, inhibiting the secretion of TNF-α, IL-6 and IL-1β, and improving mouse survival rates upon Pa infection. DTC was more effective than the other two compounds. Transcriptome sequencing identified 121 up-regulated genes and 18 down-regulated genes in DTC-treated group as compared with PBS control group. These differentially expressed genes were significantly enriched in immune pathways, with a strong activation of the IL-17 pathway. Flow cytometry analysis demonstrated significant activation of dendritic cells and proliferation of Th17 cells in splenocytes in DTC-treated group as compared with PBS control group. Conclusions:All three small compounds are able of effectively enhance antigen immunogenicity with DTC being the most effective, indicating that DTC can be used as a novel adjuvant in vaccine development.

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2019 Novel Coronavirus (2019-nCoV) is a virus identified as the cause of the outbreak of pneumonia first detected in Wuhan, China. Investigations on the transmissibility, severity, and other features associated with this virus are ongoing. Currently, there is no vaccine or therapeutic antibody to prevent the infection, and more time is required to develop an effective immune strategy against the pathogen. In contrast, specific inhibitors targeting the key protease involved in replication and proliferation of the virus are the most effective means to alleviate the epidemic. The main protease of SARS-CoV is essential for the life cycle of the virus, which showed 96.1% of similarity with the main proteaseof 2019-nCoV, is considered to be an attractive target for drug development. In this study, we have identified 4 small molecular drugs with high binding capacity with SARS-CoV main protease by high-throughput screening based on the 8,000 clinical drug libraries, all these drugs have been widely used in clinical applications with guaranteed safety, which may serve as promising candidates to treat the infection of 2019-nCoV.

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Biotechnological Pharmaceutics is a compulsory course for biotechnology undergraduates in our school. We designed and implemented an elective course named Structural Biology to help students master technological principles through practice. This elective course included in-classroom lectures and experiments; during which we encouraged students to work together, and design, prepare, implement, and complete projects; examination score of Biotechnological Pharmaceutics was used to assess learning outcomes. The results showed that students who took this course gained higher score in the examination, indicating that the elective course is effective to improve the learning effect of Biotechnological Pharmaceutics for biotechnology undergraduates.

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Biotechnological Pharmaceutics is a compulsory course for biotechnology undergraduates in our school.We designed and implemented an elective course named Structural Biology to help students master technological principles through practice.This elective course included in-classroom lectures and experiments; during which we encouraged students to work together,and design,prepare,implement,and complete projects; examination score of Biotechnological Pharmaceutics was used to assess learning outcomes.The results showed that students who took this course gained higher score in the examination,indicating that the elective course is effective to improve the learning effect of Biotechnological Pharmaceutics for biotechnology undergraduates.

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One of the major challenge in neural prosthetic device design is to ensure charge-balanced stimulation. This paper presents a new calibration technique to minimize the mismatch between anodic and cathodic current amplitudes. The proposed circuit mainly consists of a digital and an analog calibration, where a successive approximation register (SAR) logic and a comparator are used in digital calibration while a source follower is adopted in analog calibration. With a 0.18 µm high voltage CMOS process, the simulation shows that the maximum current mismatch is 45 nA (<0.05%).

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Mutants of pertussis toxin (PT) S1 subunit and filamentous hemagglutinin (FHA) type I immunodominant domain from Bordetella pertussis (B. pertussis) are considered to be effective candidate antigens for acellular pertussis vaccines; however, the substantial progress is hampered in part for the lack of a suitable in vitro expression system. In this paper, the gene sequences of a S1 mutant C180-R9K/E129G (mS1) and a truncated peptide named Fs from FHA type I immunodominant domain were linked together and constructed to pET22b expression vector as a fusion gene; after inducing with IPTG, it was highly expressed in E. coli BL21 (DE3) as inclusion body. The fusion protein FsmS1 was purified from cell lysates and refolded successfully. The result of Western blotting indicate that it was able to react with both anti-S1 and anti-FHA McAbs; antiserum produced from New Zealand white rabbits immunized with this protein was able to recognize both native PT and FHA antigens as determined by western blotting. These data have provided a novel feasible method to produce PT S1 subunit and FHA type I immunodominant domain in large scale in vitro, which is implicated for the development of multivalent subunit vaccines candidate against B. pertussis infection.

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