乳腺高效表达人溶菌酶转基因小鼠的制备

目的　研究自行构建的动物乳腺特异表达载体p2 0 5C3的表达特性。方法　将人溶菌酶 (hLYZ)cDNA插入p2 0 5C3载体 ,用获得的基因构件注射小鼠受精卵 ,用PCR和Southernblot对出生鼠进行基因整合检测 ,用微球菌溶解试验和Westernblot对表达产物进行鉴定。结果　共出生 136只F0 代小鼠 ,从中筛选出 4只 (1♀ 3♂ )转基因整合阳性鼠 ,其中的 1只母鼠不表达hLYZ ,1只雄鼠的 4只F1 代母鼠乳汁中hLYZ的表达量分别为 5、75、175和 2 0 0 μg ml,纯合后的 3只F3代母鼠乳汁中hLYZ的表达量分别为 5 2 6 μg ml、6 4 8μg ml和 75 0 μg ml,表达仅限于乳腺中 ,表达产物的相对分子质量与正常hLYZ相同。结论　p2 0 5C3能驱动hLYZcDNA在小鼠乳腺中特异和高效表达 ,可以用于动物乳腺生物反应器的研制。     

用地高辛标记探针检测转人肾素基因小鼠

采用地高辛标记探针,建立了一种快速检测和筛选转入肾素基因小鼠的方法。对实验中杂交液的选择、杂交液中探针的浓度,预杂交时间,抗体孵育前封闭时间和洗膜条件等影响因素进行了系统观察与分析,从而确定了以地高辛标记探针检测转入肾基因小鼠方法中的最佳实验条件。结果表明,该方法不仅安全,快速,而且灵敏度高,稳定性好。     

乳腺生物反应器的基础研究——载体构建,检测及反应器的建…

乳腺生物反应器的研究和开发是近年生物工程领域的研究热点。乳腺特异性表达调控的研究和表达载体的构建是该工作的基础和关键。本文介绍了乳腺蛋白基因表达调控的研究现状，外源基因乳腺特异性表达载体构建策略以及乳腺生物反应器建立方法的研究进展。     

应用转瓶和生物反应器培养表达HBsAg的哺乳动物细胞系的比较研究

大规模培养哺乳动物细胞是生产具有重要医用价值的生物制品 ,如疫苗、生长因子、单抗等的重要方法。哺乳动物细胞的大规模培养方式主要有传统的转瓶和现代的各种生物反应器。目前 ,我国乙型肝炎疫苗 (转基因中华地鼠卵巢细胞产品 )的生产采用转瓶培养方式。但近年来 ,应用载体和生物反应器大规模培养哺乳动物细胞已成为国际上细胞培养工业化最有发展前途的技术〔1〕 。本室引进了国外最新的篮式载体型生物反应器系统用于哺乳动物细胞系的大规模培养研究。本实验分别采用转瓶和生物反应器系统培养表达乙型肝炎表面抗原Ｓ和ＰｒｅＳ1的哺乳动…     

转人载脂蛋白Eε4和突变淀粉前体蛋白基因小鼠的建立

将人载脂蛋白(ApoEε4)转基因鼠和突变前体蛋白(APP)转基因小鼠交配,以建立h-ApoEε4／突变APP双转基因小鼠。共产出仔鼠23只,经PCR初步筛选,并用Southern杂交对阳性小鼠基因组DNA作进一步鉴定,得到3只双转基因小鼠。该双转基因鼠的建立为进一步阐明ApoEε4的致病作用以及对AD的研究提供了理想的研究模型。     

蓖麻蚕蛹生物反应器生产重组人表皮生长因子的研究

重组人表皮生长因子(rhEGF)已经广泛应用于医疗和化妆品。以杆状病毒AnpeNPV为基因表达载体,昆虫为生物反应器而建立的蛋白表达系统已获得成功。本文以人表皮生长因子(hEGF)基因替代柞蚕AnpeNPV中的核多角体基因而获得的AnpehEGF病毒为载体、蓖麻蚕蛹为生物反应器表达的rhEGF蛋白质,采用PCR、West-ern blot和ELISA等实验方法对其进行检测,硫酸铵沉淀和Ni-NTA Agrose亲和层析法对其进行分离纯化。实验结果显示,无论是在基因或是蛋白水平上都可检测到rhEGF的表达。AnpehEGF感染蚕蛹后第6d开始检测到rhEGF的表达量快速上升,第12d达到高峰,第3、6、9、12d的表达量分别为19.77、24.90、618.59、1 952.46ng/g,而到了病毒感染后期(第15d)出现了蛋白降解现象。表达的rhEGF通过分离纯化获得了较纯的产品。结果表明蓖麻蚕蛹作为生物反应器生产外源蛋白rhEGF是可行的,说明利用AnpeNPV和蓖麻蚕蛹可开发更加低成本而又高效的rhEGF生产新途径。     

小鼠子宫内电转基因方法的建立

目的:建立小鼠子宫内电转基因技术,比较分析转染绿色荧光蛋白(GFP)后对胚胎发育及相关蛋白表达的影响.方法:将怀孕15d的小鼠,水合氯醛麻醉后,取出两侧子宫,用毛细管注射针将2μg/μl的pCAGGS-GFP质粒0.5～1 μl准确注射到胎鼠侧脑室,在电压40 V、每次脉冲60 ms,间隔940 ms,电脉冲6次的条件下进行定时定位活体电转基因,电转后24 h取材,甲醛固定冷冻冠状切片,DAPI染细胞核观察组织形态结构变化,荧光免疫组织化学检测α-SMA的表达差异.结果:妊娠15d孕鼠转染24 h后小鼠成活率80％(8/10),胚胎成活率为54.2％(13/24),存活胚胎GFP阳性表达率为61.5％(8/13),GFP阳性表达胚胎脑组织切片,基因转染区域和正常组织区组织形态结构和α-SMA表达不存在差别.结论:成功建立了小鼠子宫内电转基因的方法.     

小鼠与人重排活化基因2启动子的比较

目的 通过比较小鼠与人重排活化基因2(RAG2)启动子，试图寻找与小鼠RAG2启动子特异性结合的转录因子。方法 采用表达luciferase的报告基因载体检测启动子的活性。采用：EMSA(electrophoresis mobility shift assay)检测与启动子结合的转录因子。结果小鼠：RAG2启动子-60／-41区域存在富G的GA盒子，而人RAG2启动子在相应位置却是富A区。突变实验结果显示，GA盒子是小鼠RAG2启动子完整活性所必须的。EMSA结果显示，Spl／Sp3结合在小鼠RAG2启动子-60／-41区域，并且Spl能够协同Pax-5、c-Myb活化小鼠RAG2启动子。结论 尽管小鼠与人RAG2启动子同源性很高，但它们结合的转录因子和功能有所不同。     

Impaired lactation in mice expressing dominant‐negative FADD in mammary epithelium

The Fas‐associated death domain (FADD/Mort1) adaptor protein was originally identified as a key mediator of apoptosis, although pleiotropic functions for FADD have also been reported. FADD‐mediated tumoricidal effects have been described in breast cancer cells; however, its physiological role in normal mammary gland epithelium is not well understood. To determine the role of FADD signaling during mammary gland development, we generated transgenic mice overexpressing dominant‐negative FADD (DN‐FADD) in mammary epithelium, using the steroid responsive mouse mammary tumor virus promoter. Transgenic mice exhibited a perturbation in lactation resulting in impaired milk production and pup growth retardation. Reduced expansion of alveoli was evident during early lactation with extensive shedding of luminal alveolar cells. Significantly more TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridinetriphosphate nick end‐labeling)‐positive cells were present at this time point and a subsequent increase in bromodeoxyuridine‐positive cells was observed. These findings suggest a role for FADD in maintaining the survival of mammary secretory alveolar cells after the establishment of lactation. Developmental Dynamics 238:1010–1016, 2009. © 2009 Wiley‐Liss, Inc.     

Adrenomedullin in mammalian and human skin glands including the mammary gland

Adrenomedullin is a peptide that has been ascribed numerous functions. In the present paper, adrenomedullin has been localized immunhistochemically in a variety of skin glands of humans, elephants and impalas: apocrine scent glands, eccrine sweat glands, holocrine glands and mammary glands. In the apocrine glands expression of adrenomedullin varied with respect to staining intensity and intracellular localization. In general, glands which appeared to be actively secreting were more strongly stained than quiescent glands. However, within a single glandular tubule, individual cells differed considerably in the staining intensity of adrenomedullin. Adrenomedullin was present in both non-lactating and lactating mammary secretory epithelia, both ducts and alveoli reacted positively. In human mammary glands displaying apocrine metaplasia, the apical protrusions were strongly positive. Furthermore, positive immunostaining was found in endothelium and often in smooth muscle cells of small arteries and veins and in mast cells as well. Many of the adrenomedullin-positive epithelial cells were most strongly stained in the area of the Golgi apparatus, the cellular apex and particularly close to the basal side of the cell membrane. This pattern suggests packaging of adrenomedullin into secretory granules and secretion both at the apex of cells and at their basis. The first form of secretion suggests exocrine secretion, the latter form endocrine secretion of adrenomedullin. A possible hormonal function is in line with basally located electron dense small secretory granules, which have been found by electron microscopy in the glandular epithelia studied.     

Secretory phenomena in the non-lactating human mammary gland

The normal non-lactating premenopausal human mammary gland has been shown by immunohistochemistry and transmission electron microscopy to secrete a number of antimicrobial peptides such as beta-defensins, the cathelicidin LL37, lactoferrin and adrenomedullin. In addition, the non-lactating gland elaborates a prominent glycocalyx at the apical membrane of the glandular epithelial cells, parts of which are shed into the lumen of endpieces and ducts. This glycocalyx includes the mucins MUC 1 and MUC 4, a strongly Alcian Blue positive palyanionic component and sulfated material stained with Aldehyde Fuchsin. MUC 1 and the Alcian Blue positive material are considered to play an antimicrobial role, too. Lactalbumin and lipid droplets also occur in the non-lactating gland. At the EM-level secretory phenomena operating by exocytosis and by means of the apocrine mechanism have been observed. Cytoskeletal components presumably play a role in apocrine secretion. Apart from secretion at the cellular apex, secretion at the cellular basis also occurs regularly, which may represent the production of para- or endocrine factors.     

慢病毒载体法制备荧光素酶转基因小鼠

目的基于慢病毒介导的转基因方法制备荧光素酶（Luc）转基因小鼠。方法制备携带Luc基因的慢病毒,将其注入小鼠单细胞受精卵卵周隙以感染受精卵,然后将胚胎移植进假孕母鼠体内以获得仔鼠,应用小动物活体成像仪及PCR等在蛋白和DNA水平上筛选和鉴定Luc转基因小鼠。结果移植慢病毒隙感染后的成活胚胎63枚。将其移植至3只假孕母鼠,其中2只怀孕,共生仔鼠11只;利用小动物活体成像仪检测Luc表达,在蛋白水平证实11只F0代中,3只（命名为S1、S2、S3）表达Luc;DNA水平检测证实,3只Luc阳性小鼠的基因组中整合有外源转基因Luc。此外,Luc转基因首建鼠基因组中整合的Luc转基因可稳定遗传至下一代,并能正常表达。Luc转基因小鼠主要脏器如睾丸、肾脏、胃、肠、肺、脑、胸腺、肝脏和心脏等均可见Luc信号,但不同脏器间Luc强度有差异。结论成功制备Luc报告基因转基因小鼠。     

Over-expression of the bovine FcRn in the mammary gland results in increased IgG levels in both milk and serum of transgenic mice

The neonatal Fc receptor (FcRn) protects immunoglobulin G (IgG) from catabolism and is also responsible for IgG absorption in the neonatal small intestine. However, whether it mediates the transfer of IgG from plasma to milk still remains speculative. In the present study, we have generated transgenic mice that over-express the bovine FcRn (bFcRn) in their lactating mammary glands. Significantly increased IgG levels were observed in the sera and milk from transgenic animals, suggesting that the over-expressed bFcRn could bind and protect endogenous mouse IgG and thus extend its lifespan. We also found that injected human IgG showed a significantly longer half-life (7-8 days) in the transgenic mice than in controls (2.9 days). Altogether, the data suggested that bFcRn could bind both mouse and human IgG, showing a cross-species FcRn-IgG binding activity. However, we found no selective accumulation of endogenous mouse IgG or injected bovine IgG in the milk of the transgenic females, supporting a previous hypothesis that IgG was transported from serum to milk in an inverse correlation to its binding affinity to FcRn.     

Involution of the sheep mammary gland

Changes in the ovine mammary gland epithelium during initiated involution were studied by light and electron microscopy. Apoptosis of the duct and alveolar epithelial cells was first identified at 2 d after weaning, reached a peak at 4 d and then progressed gradually thereafter. Apoptotic cells were phagocytosed by intraepithelial macrophages and alveolar epithelial cells. Occasional apoptotic epithelial cells were observed in the alveolar and duct lumina. The highly vacuolated cells in the alveolar and duct lumina were confirmed to be macrophages as they were CD45⁺, MHC class II⁺. Changes in myoepithelial cells involved shrinkage and extension of cytoplasmic processes into the underlying stroma and no apoptosis was observed. Regression of the blood capillaries was also by apoptosis. The resulting apoptotic bodies were either taken up by adjacent endothelial cells or were shed into the capillary lumen to be phagocytosed later by mural endothelial cells or blood monocytes. The mammary glands were completely involuted by 30 d after weaning. It was concluded that the mammary gland involutes by apoptosis, a process which allows deletion of cells without the loss of the basic architecture and the integrity of the epithelial lining of the gland.     

Induction of autoimmunity by immunization with hapten-modified hen egg lysozyme in hen egg lysozyme-transgenic mice

To understand the mechanism of autoimmunity induction, hen egg lysozyme (HEL)-transgenic (Tg) C57BL/6 (B6) mice were immunized with HEL or phosphorylcholine-conjugated HEL (PC-HEL). Repeated immunization of HEL-Tg mice with native HEL failed to induce the antibody response against HEL. However, immunization with PC-HEL generated a significant anti-HEL antibody response. Immunization of the Tg mice with dominant (HEL(74-88)) or cryptic (HEL(47-61)) T-cell epitope peptide stimulated the corresponding T-cell response and similarly yielded the anti-HEL antibody response. Predominance of immunoglobulin G1 (IgG1) anti-HEL antibody response in the HEL-Tg mice and preferential IL-4 production by HEL-specific T cells suggested the dependency of the antibody response to the presence of T helper 2. HEL-Tg mice received HEL-primed B6 T cells, but not HEL-primed Tg T cells, were able to generate anti-HEL antibody response following PC-HEL immunization. The pattern and the level of epitope peptides generated by splenic antigen-presenting cells indicated that PC-HEL results in much more efficient processing as compared to HEL. These results strongly suggest that the enhancement of antigen processing by hapten (PC) conjugation to the antigen facilitates more efficient stimulation of T cells reactive to self antigen, HEL in HEL-Tg mice resulting in the production of anti-self HEL antibody.