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Depletion of conventional mature B cells and compromised specific antibody response in bovine immunoglobulin μ heavy-chain transgenic mice

Min ZHANG,Xueqian CHENG,Dan CHU,Jingwen LIANG,Yi SUN,Li MA,Beilei XU,Min ZHENG,Meili WANG,Liming REN,Xiaoxiang HU,Qingyong MENG,Ran ZHANG,Ying GUO,Yunping DAI,Robert AITKEN,Ning LI,Yaofeng ZHAO

《农业科学与工程前沿（英文）》 2014年 第1卷 第2期   页码 158-173 doi: 10.15302/J-FASE-2014015

摘要： In this study, we introduced the bovine immunoglobulin μ heavy-chain gene (the orphaned gene on BTA11) into mouse germline cells. Bovine IgM was highly expressed in selected transgenic lines, and it largely inhibited rearrangements of the endogenous immunoglobulin heavy chain (IgH) genes in these lines. The forced expression of bovine IgM resulted in reduced numbers of pro- and pre-B cells but increased the number of immature B cells in the transgenic mice. Bovine IgM-expressing B cells can migrate from the bone marrow to the spleen, but most of the cells are arrested at the T1 transitional B cell stage, leading to a significantly lower number of T2 transitional and mature B cells in the spleen. Although the serum concentrations of endogenous IgM and IgG in the transgenic mice were significantly decreased, the IgA levels were slightly increased compared to the WT mice. The bovine IgM level in the serum was only one-tenth to one-fifth of that of endogenous mouse IgM, suggesting that most of the serum immunoglobulin were contributed by endogenous IgH gene-expressing B cells. These transgenic mice also exhibited a lower frequency of unique complementarity determining region 3 (CDR3) sequences in their VH repertoire and Vκ repertoire but exhibited an increased frequency of unique CDR3 in their Vλ repertoire. Compared to the WT mice, the transgenic mice had a significantly higher percentage of mouse IgM-expressing B cells that expressed λ chains. Finally, we showed that the transgenic mice were deficient in a specific antibody response to antigen stimulation.

关键词： bovine Ig μ heavy-chain     transgenic mice     B cell development     allelic exclusion     immune response     Ig repertoire    

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Efficient purification of cell culture-derived classical swine fever virus by ultrafiltration and size-exclusion

Ruining WANG,Yubao ZHI,Junqing GUO,Qingmei LI,Li WANG,Jifei YANG,Qianyue JIN,Yinbiao WANG,Yanyan YANG,Guangxu XING,Songlin QIAO,Mengmeng ZHAO,Ruiguang DENG,Gaiping ZHANG

《农业科学与工程前沿（英文）》 2015年 第2卷 第3期   页码 230-236 doi: 10.15302/J-FASE-2015071

摘要： Large-scale production of cell culture-based classical swine fever virus (CSFV) vaccine is hampered by the adverse reactions caused by contaminants from host cell and culture medium. Hence, we have developed an efficient method for purifying CSFV from cell-culture medium. Pure viral particles were obtained with two steps of tangential-flow filtration (TFF) and size-exclusion chromatography (SEC), and were compared with particles from ultracentrifugation by transmission electron microscopy (TEM), infectivity and recovery test, and real time fluorescent quantitative PCR (FQ-PCR). TFF concentrated the virus particles effectively with a retention rate of 98.5%, and 86.2% of viral particles were obtained from the ultrafiltration retentate through a Sepharose 4 F F column on a biological liquid chromatography system. CSFV purified by TFF-SEC or ultracentrifugation were both biologically active from 1.0×10 TCID ·mL to 3.0×10 TCID ·mL , but the combination of TFF and SEC produced more pure virus particles than by ultracentrifugation alone. In addition, pure CSFV particles with the expected diameter of 40–60 nm were roughly spherical without any visible contamination. Mice immunized with CSFV purified by TFF-SEC produced higher antibody levels compared with immunization with ultracentrifugation-purified CSFV ( <0.05). The purification procedures in this study are reliable technically and feasible for purification of large volumes of viruses.

关键词： classical swine fever virus     virus purification     tangential-flow filtration     size-exclusion chromatography    

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Tetra-detector size exclusion chromatography characterization of molecular and solution properties of

Qingbin Guo,Sheng Chang

《环境科学与工程前沿（英文）》 2017年 第11卷 第2期 doi: 10.1007/s11783-017-0922-x

摘要： Tetra-detector HPSEC was evaluated for the SMP characterization Molecular weight and intrinsic viscosity of the SMP were characterized Specific viscosity and osmotic pressure of the SMP solution were studied Approach to analyze the concentration polarization of the SMP was discussed Characterization of the molecular properties of soluble microbial products (SMP) is critical for understanding the membrane filtration and fouling mechanisms in anaerobic and aerobic membrane bioreactors (AnMBR & MBR). In this study, the distributions of the absolute molecular weight and intrinsic viscosity of SMP polysaccharides from an AnMBR were effectively determined by a high performance size exclusion chromatography (HPSEC) that was coupled with the refractive index (RI), diode array UV (DAUV), right and low angle light scattering (LS), and viscometer (Vis) detectors. Based on the tetra-detector HPSEC determined absolute molecular weights and intrinsic viscosity, a universal calibration relationship for the SMP polysaccharides was developed and the molecular conformations, average molecular weights, and hydrodynamic sizes of the SMP polysaccharides were also explored. Two factors which can be derived from the tetra-detector HPSEC analysis were proposed for the characterization of the viscous and osmotic pressure properties of the SMP polysaccharides. In addition, it was also extrapolated how to analyze the resistance characteristics of the concentration polarization layers formed in membrane filtration based on the molecular properties determined by the tetra-detector HPSEC analysis.

关键词： Soluble microbial product     Extracellular polymeric substance     Membrane bioreactor     Membrane fouling     Molecular weight     Intrinsic viscosity    

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The role of natriuretic peptide precursor A gene polymorphism in the development of coronary heart disease in Chinese Han population?

Ripen NSENGA MD, Longxian CHENG PhD, Mei’an HE PhD, Tangchun WU PhD,

《医学前沿（英文）》 2009年 第3卷 第4期   页码 437-442 doi: 10.1007/s11684-009-0074-x

摘要： Natriuretic peptide precursor A (NPPA) is synthesized, stored, and released by atrial myocytes. Previous studies have shown that NPPA plays a significant role in the regulation of coronary circulation and in atherosclerosis. Rs5065 NPPA gene polymorphism leads to the translation of NPPA with two additional arginines and has been suggested to be associated with salt-sensitive hypertension. The purpose of the present study was to investigate the relationship between the rs5065 NPPA gene polymorphism and the risk of coronary heart disease (CHD) in Chinese Han population. We genotyped the single nucleotide polymorphism (SNP) rs5065 NPPA in the human NPPA gene in 1861 sex- and age-matched subjects, comprising of 904 CHD cases and 957 controls of Chinese Han population. Genotyping of SNP was performed with Taqman SNP allelic discrimination assays by means of an ABI 7900HT. Our study showed that the frequencies of rs5065 NPPA C allele in the case and the control groups were 0.012 and 0.005, respectively. There was significant difference in C allele frequency distribution between the two groups (OR=2.607, 95% CI: 1.197−5.678, =0.012). In the case group, there was significant difference between smokers and nonsmokers with subjects carrying C allele (=0.037), and no significant difference in gender, age, fasting total cholesterol (TC), triglycerides (TG), fasting plasma glucose (FPG), body mass index (BMI), and blood pressure (BP) between the cases and the controls (>0.05). Our results suggest that the C allele of rs5065 NPPA gene polymorphism may be associated with the risk of CHD.

关键词： natriuretic peptide precursor A     coronary heart disease     gene polymorphism     allelic discrimination     polymorphism     single nucleotide    

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标题 作者 时间 类型 操作

Depletion of conventional mature B cells and compromised specific antibody response in bovine immunoglobulin μ heavy-chain transgenic mice

Min ZHANG,Xueqian CHENG,Dan CHU,Jingwen LIANG,Yi SUN,Li MA,Beilei XU,Min ZHENG,Meili WANG,Liming REN,Xiaoxiang HU,Qingyong MENG,Ran ZHANG,Ying GUO,Yunping DAI,Robert AITKEN,Ning LI,Yaofeng ZHAO

期刊论文

Efficient purification of cell culture-derived classical swine fever virus by ultrafiltration and size-exclusion

Ruining WANG,Yubao ZHI,Junqing GUO,Qingmei LI,Li WANG,Jifei YANG,Qianyue JIN,Yinbiao WANG,Yanyan YANG,Guangxu XING,Songlin QIAO,Mengmeng ZHAO,Ruiguang DENG,Gaiping ZHANG

期刊论文

Tetra-detector size exclusion chromatography characterization of molecular and solution properties of

Qingbin Guo,Sheng Chang

期刊论文

The role of natriuretic peptide precursor A gene polymorphism in the development of coronary heart disease in Chinese Han population?

Ripen NSENGA MD, Longxian CHENG PhD, Mei’an HE PhD, Tangchun WU PhD,

期刊论文