Vero细胞无血清培养基研究进展

Vero细胞是世界卫生组织和我国生物制品规程认可的生产人和动物疫苗的细胞系。为了避免外来污染和血清中不确定成分对细胞生长及其下游工作带来的影响,用无血清培养基或化学成分明确的培养基培养Vero细胞已成为病毒疫苗生产的一个重要发展趋势。Vero细胞无血清培养基的组成包括基础培养基和添加因子两大部分,常见的添加因子有转铁蛋白、胰岛素、微量元素、生长因子和维生素等。论文对Vero细胞无血清培养基的研究进展做一综述,以期为Vero细胞的无血清培养基研制及疫苗的生产提供参考。     

哺乳动物细胞无血清全悬浮培养技术研究进展

随着生物制品行业的快速发展,哺乳动物细胞无血清全悬浮培养技术已经运用到越来越多的领域中。该技术能够扩大哺乳动物细胞培养的规模,提高生物制品的产量及质量,拓宽哺乳动物细胞的应用领域,并促进哺乳动物细胞生产实现工业化与产业化。但悬浮驯化后的细胞,与父母代细胞相比,蛋白表达水平与生长调节通路均发生了不同程度的改变,使其生产性能受到影响。对此,国内外学者开展了大量的研究并取得了较好进展。作者阐述了哺乳动物细胞无血清全悬浮培养技术的研究现状以及临床生产工艺的优化策略,以期为哺乳动物细胞无血清全悬浮培养技术的发展提供参考。     

不同培养基对小鼠胚胎干细胞培养的影响

探讨了培养基中各组成(基础培养基、添加物、血清)对小鼠胚胎干细胞(ES细胞)培养的影响.结果如下:GMEM与DMEM这2种基本培养基在对ES细胞维持培养上差异不显著.GMEM 18%血清 4mmol/L谷氨酰胺 0.1mmol/L非必需氨基酸、DMEM 18%血清 4mmol/L谷氨酰胺 0.1mmol/L非必需氨基酸以及DMEM 18%血清,这3种培养基都有较好的对ES细胞维持培养能力.在培养基中不需要额外添加谷氨酰胺和非必需氨基酸.血清浓度会直接影响ES细胞培养效果,应使用18%的优质血清.     

用低血清培养基和常规培养基培养细胞对FMDV增殖影响的比较

对15批用低血清培养基培养的细胞与用常规培养基培养的细胞进行口蹄疫病毒增殖培养对比试验,结果表明:两者之间在FMDV增埴指标上,LD50和TCID50无明显差别；低血清培养基比常规培养基病变时间短1h.     

Sf9昆虫细胞悬浮培养工艺的研究

对Sf9昆虫细胞在不同培养基、培养基中是否添加血清及不同生物反应器中的培养工艺进行了研究,发现Sf9细胞在Sf900Ⅱ无血清培养基中生长比在添加10％小牛血清的Grace培养基中更好,在Sf900Ⅱ无血清培养基14 L搅拌式生物反应器分批培养细胞密度可达1.4×107/mL.过程生化特性分析表明,总氨基酸的消耗及主要代谢副产物特别是乳酸及游离氨的积累是培养后期细胞密度降低及活性下降的重要原因.本研究为Sf9细胞生物反应器培养工艺优化及利用昆虫杆状病毒蛋白表达系统高效表达重组蛋白生产亚单位疫苗奠定了良好基础.     

动物细胞无血清培养技术研究进展

生物医药是21世纪的朝阳产业,动物细胞无血清培养技术在生物医药领域中发挥着重要作用。无血清培养技术包括无血清培养基的开发、适应细胞株的驯化以及细胞规模化培养技术等关键技术,以细胞生物反应器高密度培养技术作为基础的细胞无血清悬浮培养技术推动了生物制药的快速发展。     

昆虫细胞无血清培养基研究进展

随着昆虫杆状病毒表达载体系统的广泛应用,昆虫细胞大规模无血清培养已成为一种发展趋势。目前的昆虫细胞培养基中主要有糖类、维生素、氨基酸、脂类、无机盐、有机酸等基础成分,此外还需要添加血清或酵母提取物和水解乳蛋白等血清替代物。然而使用血清会带来诸多难以解决的问题,因此开发使用血清替代物和无血清培养基已成为生物制品行业关注的主要方向。论文综述了昆虫细胞无血清培养基的研究进展,包括研究历程、研究现状、基础成分和其他添加物等。     

从小鼠类ES细胞分化群中分离培养一类衍生细胞及其培养特性

将小鼠囊胚在饲养层、无类LIF因子的培养基中培养出类ES细胞团,将该类ES细胞团传至第三代,暂停传代,继续培养,则4～5 d后该细胞团会向周围分化出一种圆而发亮的衍生细胞,该衍生细胞会不断地向周围生长,约20 d后该衍生细胞铺满培养皿底.将该衍生细胞传至铺有饲养层的培养瓶中继续传代至第七代,再将其传代至无饲养层的培养瓶中,约12 d后,其在无饲养层的培养瓶中长满瓶底.以后随着传代数的增加,该细胞长满瓶底所需时间越来越短,最后稳定在2～3 d.对传代至第30代的细胞进行生长曲线测定,并以不同的基础培养基、不同的血清浓度、不同的胰岛素浓度等条件培养该细胞,结果发现：该衍生细胞分别在DMEM高糖、DMEM低糖、DMEM-F12、PRMI1640等为基础的培养基中都能生长,但以DMEM-F12为最优.在血清浓度分别为10%、14%、18%的DMEM高糖培养基中培养显示：该细胞在高浓度血清的培养基中具有生长更好的趋势.在胰岛素浓度分别为0、0.25、0.5、1 μg/ml的DMEM高糖培养基中培养显示：该细胞在无胰岛素的培养基中无法正常生长,在0.5 μg/ml胰岛素浓度的培养基中生长最佳.     

无血清培养基的研究进展

正血清组分的复杂性和不确定性及批次间的差异增加了疫苗等细胞产品生产及质量控制的难度,同时血清易引起细菌、真菌、病毒及支原体的污染,增加了疫苗生产的安全性隐患。并且血清本身价格也比较昂贵,这些均使得血清在生产和研究中的应用存在诸多不利。在培养基中添加血清对人们所造成的这些困扰,已经使得不论是科研人员还是工业生产企业对于无血清培养产生了强烈需求。有大量实践证明无血清培养基不仅能在很大程度上避免     

国产商品化无血清培养基

上海旭太生物工程有限公司最近成功自行试制了在BHK21细胞和非洲绿猴肾Vero细胞的无血清培养基。这二种培养基在各自的细胞上按中国生物制品的操作规程的要求，在少血清时（1％～2％的血清）传代培养，而后用无血清培养基作维持培养。目前技术传代培养已可传到7代，无血清培养可维持2代，这样满足了疫苗生产目前的工艺要求。     

Evaluation of bovine embryos produced in high performance serum-free media

This review evaluates the quality of bovine embryos developed from in vitro-matured (IVM) and -fertilized (IVF) oocytes cultured in either serum-free or serum-containing media. Bovine embryos cultured in serum-supplemented medium contain numerous cytoplasmic lipid droplets and immature mitochondria compared to those cultured in serum-free medium. The accumulation of cytoplasmic lipids in embryos developed in serum-containing medium may be a result of incorporation of lipoproteins from the serum and may result in impaired function of mitochondria. The improved serum-free media (IVMD101 and IVD101) offer several advantages over culture in serum-containing medium, including increased rates of blastocyst formation and higher cell numbers. Additionally, the survival and hatching rates of embryos produced in serum-free media after post-thaw culture were superior to those of embryos produced in the serum-containing medium, suggesting that the abnormal accumulation of cytoplasmic lipids in embryos may have a negative effect on the sensitivity of embryos to chilling and freezing. These serum-free culture systems have proven to be beneficial for the production of good quality embryos from IVM-IVF bovine oocytes. Furthermore, recent studies have shown a correlation between mitochondrial function (oxygen consumption) and embryo quality. A new method using scanning electrochemical microscopy may be capable of assessing the viability and developmental potential of bovine embryos.     

Effect of insulin,transferrin and selenium and epidermal growth factor on development of buffalo oocytes to the blastocyst stage in vitro in serum-free,semidefined media

The in vitro development of buffalo oocytes up to the blastocyst stage was studied in serum-free, semidefined media containing bovine serum albumin, follicle-stimulating hormone (FSH), insulin, transferrin and selenium (ITS) and epidermal growth factor (EGF). In experiment 1, oocytes aspirated from abattoir-derived ovaries were cultured in eight serum-free, semidefined culture media containing different combinations of these four factors. In experiment 2, the maturation of buffalo oocytes and the development of the embryos were compared in a complex co-culture system and in the serum-free, semidefined media. Supplementation with FSH and EGF significantly (P < 0.05) increased the maturation rates of buffalo oocytes, and the yield of blastocysts was higher (P < 0.05) in media containing EGF and ITS. The yield of blastocysts was lower in the serum-free semidefined media (P < 0.05) than in the complex co-culture system.     

Use of a serum-free medium to produce in vitro Neospora caninum and Toxoplasma gondii tachyzoites on Vero cells

Neospora caninum and Toxoplasma gondii are cyst-forming coccidian parasites of human and veterinary clinical relevance. In vitro cultivation of the protozoans using Vero cells is usually performed in order to produce antigenic materials. Quantitative and qualitative comparisons of Vero cells grown in RPMI medium supplemented either with foetal calf serum (FCS), horse serum (HS) or a specific serum-free additive (DefCell) were performed. A serum-free cell culture system used to propagate N. caninum (NC-1 isolate) and T. gondii tachyzoites (Rh stain) were compared with the other two cell culture systems. FCS supplemented media was found to be more effective than the others in promoting Vero cells and N. caninum tachyzoites. However, it was found unable to support adequate T. gondii tachyzoite proliferation. Vero cells, T. gondii and N. caninum tachyzoite production gave similar growth patterns with either HS or DefCell supplemented media. Defcell was considered as a good alternative to supplement culture medium.     

Marek's disease virus-transformed chicken T-cell lines respond to lymphokines.

Current assays for chicken interleukin-2 (IL-2) utilize mitogen-activated lymphocytes. However, very high inter-assay variability and sporadic high background proliferation limit their usefulness. In view of the above, several Marek's disease virus (MDV)-transformed T-cell lines (which grow well in a serum-supplemented medium) were tested for a response to chicken IL-2 when grown in serum-free media. Five of six lines examined showed a dose-dependent proliferative response to chicken T-cell conditioned media. One line, MDCC-CU14, was chosen for further studies. In addition to the tumor cells' dose-dependent responses to semi-purified chicken IL-2, they expressed T-cell activation antigens on the cell surface. Furthermore, the level of surface expression was enhanced on cells provided IL-2. Co-incubation of the tumor cells with monoclonal antibody INN-CH-16 (specific for an antigen on the surface of activated T-cells) and IL-2 resulted in a modulation of lymphokine-induced proliferation. Together, these data suggest that signalling mechanisms in MDV T-cell tumors are intact and that these lines can be used as an assay for chicken T-cell lymphokines. Furthermore, they provide an interesting model for the study of avian and mammalian T-cell transformation. Implications for the study of Marek's disease are also discussed.     

昆虫杆状病毒表达系统研究进展及其应用展望

昆虫杆状病毒表达系统作为四大表达系统之一,已广泛应用于重组蛋白的合成。该系统具有如多角体启动子控制下的高效表达,比较完善的转译后加工修饰,容易从无血清培养上清中纯化,无内毒素污染等特点。杆状病毒表达载体系统研究的最新进展:高强度早期启动子群杆状病毒转移载体的成功合成,以扩大寄主范围和增进重组蛋白稳定性为目的的亲本病毒的改造;通用的昆虫细胞培养基配方的不断优化,特定昆虫细胞株培养基的研制和适用于大规模悬浮培养的无血清培养基的商品化;旨在进行复杂糖基化及提供相对稳定细胞环境的宿主细胞工程;以新标记物(tag)载体和相关亲和层析方法为代表的蛋白质高效纯化方法的进步。昆虫杆状病毒表达载体系统在基础研究、医药卫生和农业上具有广阔的应用前景。     

Bovine costimulator. I. Production kinetics,partial purification,and quantification in serum-free Iscove's medium

Bovine peripheral blood leukocytes were examined for blast transformation in response to T-cell lectins in serum-containing RPMI 1640 medium and serum-free Iscove's medium. Phytohemagglutinin-induced blastogenesis was significantly greater in Iscove's medium than in RPMI containing ten percent fetal calf serum. Concanavalin A-induced blast transformation was equivalent in both media. However, the kinetics of lectin response and the quantity of lectin required for optimum blastogenesis was considerably different in the two culture media. Concanavalin A-induced blast transformation of bovine thymocytes in Iscove's medium revealed that at a concentration of 10⁶ cells/ml, inconsequential blastogenesis ensued; but at 10⁷ cells/ml blast transformation was significant and dose-dependent. Therefore, conditioned media from concanavalin A-stimulated bovine peripheral blood leukocytes, prepared in serum-free Iscove's medium, were assayed for costimulator activity using bovine thymocytes at 10⁶ cells/ml in Iscove's medium as indicator cells. Both optimum lectin requirements and cell concentrations for production of costimulator activity were found. Conditioned medium, generated with the total exclusion of serum and with optimal costimulator activity, was fractionated via gel exclusion chromatography. A quantitative assay was described, and results indicated that bovine costimulator had an approximate molecular weight of 20,000 daltons.