Development of functional antibodies against influenza B virus by activation-induced cytidine deaminase in hybridoma cells

Highlights
1. Class-switch recombination was mimicked in hybridomas through a controllable expression system of activation-induced cytidine deaminase.
2. IgG antibodies were generated through this system in an anti-Flu B IgM hybridoma 7G1.
3. IgG1 and IgG2a subtypes of 7G1 present improved antiviral activity in vitro and in vivo.     

Scutellarein inhibits RANKL-induced osteoclast formation in vitro and prevents LPS-induced bone loss in vivo

Osteoporosis, arthritis, Peget's disease, bone tumor, periprosthetic joint infection, and periprosthetic loosening have a common characteristic of osteolysis, which is characterized by the enhanced osteoclastic bone resorptive function. At present, the treatment target of these diseases is to interfere with osteoclastic formation and function. Scutellarein (Scu), a flavonoids compound, can inhibit the progress of tumor and inflammation. However, the role of Scu in inflammatory osteolysis isn’t elucidated clearly. Our study showed that Scu inhibited bone destruction induced by LPS in vivo and OC morphology and function induced by RANKL in vitro. Mechanistic studies revealed that Scu suppressed osteoclastic marker gene expression by RANKL-induced, such as Ctsk9, Mmp9, Acp5, and Atp6v0d2. In addition, we found that the inhibition effects of osteoclastogenesis and bone resorption function of Scu were mediated via attenuating NF-κB and NFAT signaling pathways. In conclusion, the results showed that Scu may become a potential new drug for the treatment of inflammatory osteolysis.     

Time-Course Association Mapping of the Grain-Filling Rate in Rice (Oryza sativa L.)

Detecting quantity trait locus (QTLs) and elite alleles that are associated with grain-filling rate (GFR) in rice is essential for promoting the utilization of hybrid japonica rice and improving rice yield. Ninety-five varieties including 58 landraces and 37 elite varieties from the core germplasm collection were genotyped with 263 simple sequence repeat (SSR) markers. The GFR of the 95 varieties was evaluated at five stages, 7, 14, 21, 28 and 35 days after flowering (DAF) both in 2011 and 2012. We found abundant phenotypic and genetic diversity in the studied population. A population structure analysis identified seven subpopulations. A linkage disequilibrium (LD) analysis indicated that the levels of LD ranged from 60.3 cM to 84.8 cM and artificial selection had enhanced the LD. A time-course association analysis detected 31 marker-GFR associations involving 24 SSR markers located on chromosomes 1, 2, 3, 4, 5, 6, 8, 9, 11 and 12 of rice at five stages. The elite alleles for high GFR at each stage were detected. Fifteen excellent parental combinations were predicted, and the best parental combination ‘Nannongjing62401×Laolaihong’ could theoretically increase 4.086 mg grain^-1 d^-1 at the five stages. Our results demonstrate that the time-course association mapping for GFR in rice could detect elite alleles at different filling stages and that these elite alleles could be used to improve the GFR via pyramiding breeding.     

Sigma receptor knockdown augments dysfunction and apoptosis of beta cells induced by palmitate

Sigma-1 receptor (Sig-1R) is located in the endoplasmic reticulum (ER) and clustered on the mitochondria related endoplasmic membranes, which are involved in the regulation of nervous system disease. Here, we designed Sig-1R silence MIN6 cells and studied the influence of Sig-1R silence on beta cells. We showed Sig-1R inactivation in MIN6 cells could not only decrease cell proliferation but also inhibit cell cycle, and this inhibitory effect on cell cycle might be achieved by regulating the FoxM1/Plk1/Cenpa pathway. Moreover, Sig-1R deficiency increased MIN6 cells sensitivity to lipotoxicity, exaggerated palmitate (PA)-induced apoptosis, and impaired insulin secretion. On the other hand, ER chaperone GRP78 and ER proapoptotic molecules CHOP increased in Sig-1R knockdown MIN6 cells. The ATP level decreased and reactive oxygen species (ROS) increased in this kind of cells. Furthermore not only GRP78 and CHOP levels, but also ATP and ROS levels changed more in Sig-1R silence cells after cultured with PA. Therefore, Sig-1R deficiency exaggerated PA induced beta cells apoptosis by aggravating ER stress and mitochondrial dysfunction. Together, our study showed that Sig-1R might influence the proliferation, apoptosis, and function of beta cells.     

Preparation of Immunoglobulin Y (IgY) Against Lipopolysaccharide using Gel Chromatography from the Yolks of Eggs Laid by Immunized Hens

The objective is to prevent and treat injuries caused by lipopolysaccharide (LPS) from gram negative bacteria in animals and humans, we produced antibodies against LPS from egg yolk. LPS from E. coli (O111:B4) mixed with Freund’s Adjuvant was used as the immunogen to immunize Roman hens. Immunized eggs were collected, and immunoglobulin Y (IgY) was purified using a water solution, salt precipitation and gel chromatography. The molecular weight and purity were determined by SDS–PAGE, the antibody titer by noncompetitive enzyme-linked immunosorbent assay (ELISA) and antibody activity against LPS by the mortality of mice intraperitoneally injected with LPS or LPS-IgY solutions. IgY against LPS showed two protein bands at 68 and 26 kDa on the gel; the antibody titer was almost 1:25,600. After incubation with LPS, IgY decreased the mortality of mice challenged with LPS. This study provided an efficient way to produce high-titer egg yolk antibodies, which could attenuate lethal effects of LPS, by immunizing hens. Furthermore, the LPS antibody was purified well using a water solution, salting-out and gel chromatography.     

Polyvalent DNA prime and envelope protein boost HIV-1 vaccine elicits humoral and cellular responses and controls plasma viremia in rhesus macaques following rectal challenge with an R5 SHIV isolate

Immunization of macaques with multivalent DNA encoding gp120 genes from HIV-1 subtypes A, B, C and E and a gag gene followed by boosting with homologous gp120 proteins elicited strong anti-gp120 antibodies capable of neutralizing homologous and to a lesser degree heterologous HIV-1 isolates. Both Env- and Gag-specific cell mediated immune (CMI) responses were detected in the immunized animals. Following rectal challenge with an SHIV isolate encoding HIV-1(Ba-L)env, plasma viremia in the infected immunized animals was significantly lower than that observed in the na?ve animals. Further, one of six immunized animals was completely protected whereas all six na?ve animals were infected. These results demonstrate that a vaccine based on priming with a polyvalent DNA vaccine from multiple HIV-1 subtypes followed by boosting with homologous Env proteins elicits anti-HIV-1 immune responses capable of controlling rectal transmission of SHIV(Ba-L).     

安徽某铁矿酸性矿山废水中真核生物的群落结构特征

【目的】研究酸性矿山废水中真核生物的群落结构特征以及群落结构与环境因子之间的关系。【方法】利用分子生物学方法,通过构建18S rRNA基因克隆文库进行系统发育分析;利用典范对应分析(CCA)方法解析环境因子对真核生物群落结构的影响。【结果】系统发育分析表明:子囊菌门(Ascomycota)普遍存在于4个样品中,并在样品1和样品3中占统治地位,而绿藻门(Chlorophyta)和担子菌门(Basidiomycota)分别为样品2和样品4的优势类群。该酸性矿山废水中的克隆与许多已知的耐酸耐重金属真核生物亲缘关系较近,如Sarcinomyces petricola、Penicillium janthinellum、Coniochaeta velutina、Trichoderma viride、Chlorellaprotothecoides var.acidicola、Ochromonas sp.等。此外,样品中还存在大量的已知人类病原菌,如Lecythophorahoffmannii、Cryptococcus neoformans。CCA分析表明:TN、SO24-、Fe2+、Eh是影响真核生物群落空间分布的主要因素。【结论】所研究的酸性矿山废水中真核生物的群落结构在时间和空间上均有较大差异,这可能与水体的理化性质有关;高含量人类致病菌的存在是之前研究所未发现的;酸性环境中真核生物的生态学研究有助于开发高效处理酸性矿山废水的方法。     

Proteoglycan metabolism, cell death and Kashin-Beck Disease

Kashin-Beck Disease (KBD) is an endemic, chronic and degenerative osteoarthropathy principally occurring in children. The characteristic pathological change of KBD is chondrocyte necrosis in hyaline articular cartilage. Proteoglycans are one of the major components in the extracellular matrix of articular cartilage, and disrupted proteoglycan metabolism and loss of proteoglycans in articular cartilage from KBD patients has been observed. In this mini-review, we discuss the close relationship between chondrocyte death including necrosis and loss of proteoglycan, and its potential mechanism during KBD onset and development, which may provide new clues for KBD research.     

DNA methylation profiling distinguishes three clusters of breast cancer cell lines

Methylation change plays an important role in many cellular systems, including cancer development. During recent years, genome-wide or large-scale methylation data has become available thanks to rapid advances in high-throughput biotechnologies. So far, researchers have always used gene expression profiling to study disease subtypes and related therapies. In this study, we investigated methylation profiles in 30 breast cancer cell lines using methylation data generated by microarray technologies. Strong variation of the number of methylation peaks was found among these 30 cell lines; however, more peaks were found in the upstream regions than in downstream regions of genes. We further grouped the methylation profiles of these cell lines into three consensus clusters. Finally, we performed an integrative analysis of breast cancer cell lines using both methylation and gene-expression profiling data. There was no significant correlation between methylation-profiling subtypes and gene-expression profiling subtypes, suggesting the complex nature of methylation in the regulation of gene expression. However, we found basal B cell lines appeared exclusively in two methylation clusters. Although these results are preliminary, this study suggests that methylation profiling might be promising in disease subtype classification and the development of therapeutic strategies.