2.Preparation and characterization of an egg yolk antibody (IgY) against the recombinant human A rotavirus VP8
Zhi ZHANG ; Weidong HU ; Xiaoyang ZOU ; Tianyou LI ; Bingchao LI ; Zaixin LI
Chinese Journal of Microbiology and Immunology 2014;(4):310-314
Objective To prepare an egg yolk antibody ( IgY) against the recombinant human A rotavirus VP8 and evaluate its biological characteristics .Methods The complete VP4 gene was used as the template to clone VP8 DNA fragment by PCR .The VP8 gene was then cloned into the vector pET 28a for ex-pression of VP8 protein in the prokaryotic system.The expression plasmid of pET28a-VP8,identified by DNA sequencing,was transformed into E.coli BL21 to induce the expression of protein by 0.5 mmol/L IPTG at 30℃.The purified and refolded recombinant VP 8 protein was used to immunize laying hens in combination with complete Freund′s adjuvant ( CFA ) .Anti-VP8 IgY antibodies were extracted from egg yolks by using water dilution-ultrafiltration assay and were further analyzed by SDS-PAGE,ELISA,Western blot and Dot blot assay,respectively.Results The recombinant VP8 protein was expressed in E.coli BL21 as an inclusion body and its molecular weight was about 35 ×10 3 .The VP8 protein was well refolded in a buffer containing Tris-HCl (pH8.0).The isolated anti-VP8 IgY antibodies showed a high titer of 1∶100 000 and a high stabil-ity under the condition of pH3-11 and temperature 25-65℃.Moreover,the anti-VP8 IgY antibodies specific-ally recognized the wild type human A rotavirus .Conclusion The prepared anti-VP8 IgY antibodies showed the advantages of high titer ,good specificity and stability .It might be used as the tool in further investigation for the prevention and treatment of diarrhea caused by human A rotavirus .
3.Internal audit of Organ Procurement Organization under the requirements of high-quality development
Shunliang YANG ; Lizhi LYU ; Zhelong JIANG ; Yushu LI ; Dong WANG ; Zaixin WU
Organ Transplantation 2023;14(4):485-
High-quality development is the primary task of building a socialist modern country in an all-round way. Organ donation and transplantation in China are evolving from high-speed growth to high-quality development, which put forward new requirements for the safe, stable and healthy operation of Organ Procurement Organization (OPO). Safety is the foundation and prerequisite for achieving the goal of high-quality development. As an independent and comprehensive department, internal audit should create new achievements in the new era. The department should include OPO and organ donation into the scope of internal audit, shift the emphasis upon the overall development of organ donation. Besides, it should fully consider the actual situation in different places, conduct all-round, objective and fair evaluation, provide evaluation and consulting services for OPO to properly implement organ donation, and give full play to the supervision and prevention role of internal audit.
4.In-silico annotation of the chemical composition of Tibetan tea and its mechanism on antioxidant and lipidlowering in mice
Ning WANG ; Linman LI ; Puyu ZHANG ; Muhammad Aamer MEHMOOD ; Chaohua LAN ; Tian GAN ; Zaixin LI ; Zhi ZHANG ; Kewei XU ; Shan MO ; Gang XIA ; Tao WU ; Hui ZHU
Nutrition Research and Practice 2023;17(4):682-697
BACKGROUND/OBJECTIVES:
Tibetan tea is a kind of dark tea, due to the inherent complexity of natural products, the chemical composition and beneficial effects of Tibetan tea are not fully understood. The objective of this study was to unravel the composition of Tibetan tea using knowledge-guided multilayer network (KGMN) techniques and explore its potential antioxidant and hypolipidemic mechanisms in mice.MATERIALS/METHODS: The C57BL/6J mice were continuously gavaged with Tibetan tea extract (T group), green tea extract (G group) and ddH 2 O (H group) for 15 days. The activity of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in mice was detected.Transcriptome sequencing technology was used to investigate the molecular mechanisms underlying the antioxidant and lipid-lowering effects of Tibetan tea in mice. Furthermore, the expression levels of liver antioxidant and lipid metabolism related genes in various groups were detected by the real-time quantitative polymerase chain reaction (qPCR) method.
RESULTS:
The results showed that a total of 42 flavonoids are provisionally annotated in Tibetan tea using KGMN strategies. Tibetan tea significantly reduced body weight gain and increased T-AOC and SOD activities in mice compared with the H group. Based on the results of transcriptome and qPCR, it was confirmed that Tibetan tea could play a key role in antioxidant and lipid lowering by regulating oxidative stress and lipid metabolism related pathways such as insulin resistance, P53 signaling pathway, insulin signaling pathway, fatty acid elongation and fatty acid metabolism.
CONCLUSIONS
This study was the first to use computational tools to deeply explore the composition of Tibetan tea and revealed its potential antioxidant and hypolipidemic mechanisms, and it provides new insights into the composition and bioactivity of Tibetan tea.
5.Enhanced immune response of a novel T-cell immunogen in vaccine for foot-and-mouth disease.
Qing ZHAO ; Pu SUN ; Zaixin LIU ; Pinghua LI ; Huifang BAO ; Yimei CAO ; Xingwen BAI ; Yuanfang FU ; Zengjun LU ; Dong LI
Chinese Journal of Biotechnology 2011;27(9):1281-1291
We investigated the enhanced immune response of a recombinant T cell immunogen as an effective cellular immune adjuvant. The T cell immunogen named TI contained several T cell epitopes from the VP1, VP4, 3A and 3D proteins of foot-and-mouth disease virus (FMDV) and two pan-T helper (T(H)) cell sites to broaden the immunogenicity of the protein. Meanwhile, another fusion protein named OA-VP1 was expressed in bacteria, which contained two VP1 proteins of O and Asia1 type FMDV. Mice were vaccinated with commercially inactivated vaccine or OA-VP1 protein with or without the TI immunogen. The results show that mice inoculated with inactivated vaccine or OA-VP1 protein supplemented with TI immunogen produced significantly higher level of neutralizing antibodies (P < 0.01 or P < 0.05) than the mice only inoculated with inactivated vaccine or OA-VP1 protein by microneutralization assay. An obvious increase in T cell number by flow cytometric analysis and significantly higher concentration of IFN-gamma secreted in culture media of spleen lymphocytes were observed in groups supplemented with TI immunogen (P < 0.01). TI immunogen was an effective stimulator for humoral and cellular immunity and could help improve the immunogenicity of inactivated vaccine or protein subunit vaccine.
Adjuvants, Immunologic
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pharmacology
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Animals
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Capsid Proteins
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genetics
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immunology
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Epitopes, T-Lymphocyte
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genetics
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immunology
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Foot-and-Mouth Disease
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immunology
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prevention & control
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virology
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Foot-and-Mouth Disease Virus
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immunology
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Immunization
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Mice
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Viral Vaccines
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genetics
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immunology
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pharmacology
6. Isolation of cariogenic Streptococcus mutans and the inhibitory effect of egg yolk antibody on caries
Xingling LI ; Zhi ZHANG ; Zaixin LI ; Ningjun DENG ; Bo ZENG ; Yongmei CHEN
Chinese Journal of Stomatology 2017;52(4):248-253
Objective:
To isolate the cariogenic
7.Five-case report for transvenous epicardial pacemaker implantation via coronary sinus in patients after prosthetic tricuspid valve replacement.
Qiying XIE ; Tianlun YANG ; Zelin SUN ; Xiaoqun PU ; Chuanchang LI ; Zaixin YU ; Jun YI ; Jinhua DENG ; Shuangyuan MENG
Journal of Central South University(Medical Sciences) 2015;40(7):820-824
Five patients after prosthetic tricuspid valve, who received pacemaker implantation via coronary sinus during Oct, 2011 and Jul, 2014, were enrolled. Pacemakers were implanted via coronary vein in 5 patients without complications. The stimulation thresholds keep stable and symptoms (such as short breath and fatigue) were disappeared during the follow-up. For patients after tricuspid valve replacement, implantation of pacemaker via coronary sinus provides a safe and invasive approach and avoids opening the chest again.
Cardiac Surgical Procedures
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Coronary Sinus
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Heart Valve Prosthesis Implantation
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Humans
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Pacemaker, Artificial
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Tricuspid Valve
8.A method for immortalizing swine monoclonal B cells secreting anti-PRRSV antibodies.
Jian WANG ; Jing ZHANG ; Kun LI ; Pu SUN ; Guoxiu LI ; Jiaoyang LI ; Yimei CAO ; Zhixun ZHAO ; Hong YUAN ; Yuanfang FU ; Pinghua LI ; Dong LI ; Zaixin LIU ; Zengjun LU
Chinese Journal of Biotechnology 2022;38(8):2872-2882
Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease caused by porcine reproductive and respiratory syndrome virus (PRRSV), which causes great economic losses. At the moment, no effective neutralizing antibody is available for scientific research and treatment. Therefore, developing a method for screening the neutralizing monoclonal antibodies is of great significance for the prevention and treatment of PRRSV and the screening of antigen sites. Monoclonal antibodies have been widely used in the treatment and diagnosis of many human and animal diseases. Therefore, screening effective neutralizing antibodies for different pathogens is an urgent task. Among the methods for monoclonal antibody screening, B cell immortalization is an effective method to obtain neutralizing monoclonal antibody. Specifically, in this study, the bcl-6 and bcl-xl genes were connected by f2a and then the yielded product was ligated to a vector for retrovirus packaging. The swine lymphocytes immunized with PRRSV were infected the yielded mature viruses and cultured in the complete medium containing CD40L and IL21 cytokines. Then, CD21 was used as the marker to screen B cells with the magnetic bead method. Finally, monoclonal B cells were obtained and the secretion of antibodies was tested. The results showed that the plasmid, either being transfected alone or with the packaged plasmids, could be expressed, and that the packaged retrovirus could infect the cells. Moreover, the infected lymphocytes secreted antibodies, so did the screened B cells. Therefore, the method for screening monoclonal antibody against PRRSV was successfully established.
Animals
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Antibodies, Monoclonal
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Antibodies, Neutralizing
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Antibodies, Viral
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Humans
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Porcine Reproductive and Respiratory Syndrome/prevention & control*
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Porcine respiratory and reproductive syndrome virus/genetics*
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Swine
9.Development of a sandwich ELISA for detecting 3AB non-structural protein of foot-and-mouth disease virus.
Yuanfang FU ; Wei HE ; Pu SUN ; Lin YANG ; Huifang BAO ; Yimei CAO ; Xingwen BAI ; Pinghua LI ; Dong LI ; Yingli CHEN ; Lei LIU ; Zengjun LU ; Zaixin LIU
Chinese Journal of Biotechnology 2020;36(11):2357-2366
Antigenic purity is important for quality control of the foot-and-mouth (FMD) whole virus inactivated vaccine. The recommended method for evaluation the antigenic purity of FMD vaccine is to check the serum conversion to non-structural protein (NSP) 3AB antibody after 2 to 3 times inoculation of animals with inactivated vaccine. In this study, we developed a quantitative ELISA to detect the amount of residual 3AB in vaccine antigen, to provide a reference to evaluate the antigenic purity of FMD vaccine. Monoclonal antibody (Mab) of NSP 3A and HRP-conjugated Mab of NSP 3B were used to establish a sandwich ELISA to quantify the NSP 3AB in vaccine antigen of FMD. Purified NSP 3AB expressed in Escherichia coli was serially diluted and detected to draw the standard curve. The detectable limit was determined to be the lowest concentration of standard where the ratio of its OD value to OD blank well was not less than 2.0. Results: The OD value was linearly corelated with the concentration of 3AB protein within the range between 4.7 and 600 ng/mL. The correlation coefficient R² is greater than 0.99, and the lowest detectable limit is 4.7 ng/mL. The amount of 3AB protein in non-purified inactivated virus antigen was detected between 9.3 and 200 ng/mL depending on the 12 different virus strains, whereas the amount of 3AB in purified virus antigen was below the lowest detectable limit. The amount of 3AB in 9 batches of commercial FMD vaccine antigens was between 9.0 and 74 ng/mL, whereas it was below the detectable limit in other 24 batches of commercial vaccine antigens. Conclusion: the sandwich ELISA established in this study is specific and sensitive to detect the content of 3AB protein in vaccine antigen of FMD, which will be a useful method for evaluation of the antigenic purity and quality control of FMD inactivated vaccine.
Animals
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Antibodies, Viral
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Enzyme-Linked Immunosorbent Assay
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Foot-and-Mouth Disease/prevention & control*
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Foot-and-Mouth Disease Virus
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Viral Nonstructural Proteins/genetics*
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Viral Vaccines