Survival of bone marrow-derived mesenchymal stem cells in a xenotransplantation model.

Mesenchymal stem cells (MSCs) are immunoprivileged and the allogeneic MSCs implantation has been used to facilitate tissue repairs such as bone and cartilage defect. The present study aimed to investigate the feasibility of xenogeneic MSCs implantation. Green fluorescent protein (GFP) transgenic rat bone marrow-derived MSCs were loaded into HA/TCP Skelite blocks and implanted intramuscularly into the quadriceps of the MF1 and SCID mice. After 11 weeks, the implants were harvested and processed for further examinations. The peripheral blood mononuclear cells of each animal were also collected to measure the in vitro immune responses using mixed lymphocyte culture and cytotoxic assay. In the MF1 mice, some surviving MSCs were found in the explants after 11 weeks of implantation, but there was no sign of new bone formation as neither osteocalcin mRNA nor osteoid tissues were detected in the explants; the lymphocyte proliferation and cytotoxicity against donor MSCs were significantly increased in the animals with the xenogeneic MSCs implantation compared with the control littermates without transplantation. In the control SCID mice, osteoid tissues derived from the implanted MSCs were found in the explants; no difference of lymphocyte proliferation and cytotoxicity against the donor MSCs was detected between the SCID mice with or without MSCs implantation. The data suggested that rat MSCs survived the 11 weeks of xenotransplantation in the MF1 mice, but the increased host immune sensitization led to the impaired in vivo osteogenesis potential of MSCs.     

间隙连接蛋白26-EGFP载体的构建与表达

目的：构建间隙连接蛋白(connexin，Cx)26-EGFP真核表达载体，观察其在细胞内的表达和功能情况。方法：经RT-PCR获得Cx26基因全长片段，重组至有增强绿色荧光蛋白标记的真核表达载体pEGFP-N2中，经脂质体转染至宫颈癌Hela细胞中，通过激光共聚焦显微镜、免疫细胞化学方法、蛋白印迹法(Western blot)检测蛋白表达，应用荧光染料(Lucifer Yellow)细胞划痕法检测细胞间间隙连接通信状态。结果：转染细胞有增强绿色荧光蛋白及Cx26的表达，细胞间间隙连接通讯恢复。结论：融合表达增强绿色荧光蛋白后，不影响间隙连接蛋白的功能，在间隙连接蛋白的研究中，pEGFP-N载体可以作为一个优选载体。     

绿色荧光蛋白在成人胰腺来源的巢蛋白阳性干细胞中的表达

目的 研究绿色荧光蛋白(GFP)在成人胰腺来源的巢蛋白阳性干细胞(NPSCs)中的表达。方法 应用脂质体(lipofectin)法，将含GFP基因的质粒pEGFP—N1转染至培养的NPSCs中，用荧光显微镜观察GFP的表达。结果 大约40％的NPSCs呈现强度较均匀的绿色荧光。结论 GFP基因可以被转染至NPSCs中，并在NPSCs中表达。     

Hdac1 Regulates Differentiation of Bipotent Liver Progenitor Cells During Regeneration via Sox9b and Cdk8

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Immunization with apoptotic pseudovirus transduced cells induces both cellular and humoral responses: a proof of concept study in macaques

Dendritic cells are able to present viral antigens to T-cells after uptake of apoptotic bodies derived from virus-infected cells. Immunization with virus-infected apoptotic cells was previously shown to induce HIV-specific immune responses in mice. Here we evaluate the safety and immunogenicity of immunization with activated apoptotic cells in non-human primates using autologous T-cells infected with replication defective VSV pseudotyped SIV(mac239)Δenv. Animals were immunized with γ-irradiated activated T-cells carrying the VSVenvSIV(mac239)Δenv pseudovirus. SIV Gag-specific cellular immune responses were induced as early as two weeks after the first immunization eliciting a biased IFN-γ and IL-2 response. In addition, induction of SIV Gag-specific antibody responses and high titer neutralizing activity against the SIV pseudovirus harboring a VSV-env were detected after two immunizations. The vaccinated group and a control group of Chinese rhesus macaques were intravenously challenged with pathogenic SIV(mac251.) All animals became infected, but SIV-replication was effectively suppressed (below 100 copies/ml) in several animals in both groups. However the group immunized with apoptotic cells revealed better preservation of the gut CD4(+) T-cell compartment. Viral control was inversely correlated with an early (4 weeks) but transient increase in the percentage of Ki67(+)CD4(+) peripheral blood T-cells (Spearman -0.73). We here show that immunizations with activated apoptotic lymphocytes expressing transduced SIV genes result in induction of both cellular and humoral immune responses. This study provides evidence for an immunological principle demonstrating that certain apoptotic cells can be considered as carriers of antigens directing immune responses in macaques.     

蓝氏贾第虫病毒体外转录体转染条件的研究

目的 确定蓝氏贾第虫病毒体外转录体电穿孔转染的最佳条件。方法 以不同的电击缓冲液、电压及脉冲时间应用GLV和GFP嵌合体体外转录体电穿孔转染蓝氏贾第虫，测定转染虫体的存活率及GFP表达量。结果 在不同转染条件下GLV和GFP嵌合体体外转录体均能成功转染蓝氏贾第虫，且在cytomix缓冲液、1000V／cm、8ms电击条件下，对虫体损伤最小，GFP表达量最高。结论 本试验确定的蓝氏贾第虫病毒体外转录体电穿孔转染最佳条件是电击缓冲液为cytornix缓冲液，电压为1000V／cm、脉)中时间为8ms。     

Distinctive population of Gfap‐expressing neural progenitors arising around the dentate notch migrate and form the granule cell layer in the developing hippocampus

In the adult hippocampus, granule cells continue to be generated from astrocyte‐like progenitors expressing glial fibrillary acidic protein (GFAP) that differ from embryonic neocortical progenitors. However, during the embryonic period, dentate granule neurons and neocortical pyramidal neurons are derived from the ventricular zone (VZ) of the pallium. Our question is when do GFAP+ progenitors of granule neurons appear in the developing hippocampus during the embryonic period, and how do they form the granule cell layer. The present analysis using Gfap‐GFP transgenic mice shows that the GFP+ distinct cell population first appears in the VZ of the medial pallium at the dorsal edge of the fimbria on embryonic day 13.5. During the perinatal period, they form a migratory stream from the VZ to the developing dentate gyrus, and establish the germinal zones in the migratory stream, and the marginal and hilar regions in the developing dentate gyrus. GFP+ cells in these regions were positive for Sox2 and Ki67, but negative for BLBP. GFP+ cells with Neurogenin2 expression were largely distributed in the VZ, whereas GFP+ cells with Tbr2 and NeuroD expressions were seen in the migratory stream and developing dentate gyrus. Prox1‐expressing GFP+ cells were restricted to the developing dentate gyrus. These results suggest that distinctive Gfap‐expressing progenitors arising around the dentate notch form germinal regions in the migratory stream and the developing dentate gyrus where they differentiate into granule neurons, indicating that distinct astrocyte‐like neural progenitors continue to generate granule neurons, from the beginning of dentate development and throughout life. J. Comp. Neurol. 522:261–283, 2014. © 2013 Wiley Periodicals, Inc.     

蚊期和红内期持续表达绿色荧光蛋白的重组约氏疟原虫

目的 构建蚊期、红内期持续表达绿色荧光蛋白（GFP）的约氏疟原虫BY265株。 方法 用SacⅡ酶酶切含有伯氏疟原虫ssu-rrna基因和GFP基因的重组质粒pl0017使之线性化,用电转化的方法将该重组质粒转化入红内期约氏疟原虫BY265株,获BY265-EGFP重组疟原虫,尾静脉注射感染昆明小鼠,24～30 h后用乙胺嘧啶饲喂小鼠5～6 d,鼠尾静脉采血涂片观察原虫感染率。以疟原虫基因组DNA为模板,PCR鉴定转染重组质粒pl0017的约氏疟原虫。斯氏按蚊叮咬感染BY265-EGFP重组疟原虫的小鼠,按蚊血餐后第7天和第16天解剖蚊胃和唾液腺,观察疟原虫能否在蚊体内正常发育。 结果 荧光显微镜观察到呈绿色荧光的红内期各期形态正常的约氏疟原虫。PCR检测结果表明,GFP和ssu-rrna基因已成功整合到约氏疟原虫基因组中。按蚊感染实验证实重组BY265株能在蚊体内正常发育。 结论 构建了蚊期、红内期持续表达绿色荧光蛋白的约氏疟原虫。     

CD2AP真核表达载体的构建及在COS-7细胞中的表达定位

目的:构建pEGFP-CD2AP真核表达载体,检测其在COS-7细胞中的表达.方法:PCR扩增CD2相关蛋白(CD2-associated protein,CD2AP)全长编码序列,PCR产物连接入pGEM T-Easy载体,经测序确认无误后,亚克隆入pEGFP-C2构建pEGFP-CD2AP真核表达载体,采用Lipofectamine 2000转染COS-7细胞,荧光显微镜检测报告基因表达产物EGFP.结果:pEGFP-CD2AP表达载体转染COS-7细胞后,可在细胞内观察到报告基因和目的基因的表达产物.结论:pEGFP-CD2AP真核表达载体构建成功,并可在细胞内表达,这将为今后的CD2AP功能研究奠定基础.     

高危型HPV-16E6在小鼠骨髓源性树突细胞的表达

目的探讨高危型HPV-16E6在树突细胞中的定位。方法构建真核表达载体pGFP-16E6,转染小鼠骨髓源性的树突细胞,在荧光显微镜下动态观察高危型HPV-16E6蛋白在树突细胞内的定位和表达水平。结果树突细胞在分别转染pGFP-16E6和pEGFP-C1质粒后,GFP-16E6主要定位于细胞核内,而对照组的只表达GFP的蛋白则均匀分布于树突细胞。蛋白表达水平的检测表明,在转染树突细胞后的12h,GFP-16E6和GFP蛋白开始表达（荧光强度分别为31.29,39.52）,转染后至24h,蛋白表达均到达高峰（荧光强度分别为119.37,134.23）,24h后,蛋白表达逐渐降低。结论 HPV-16E6主要定位于树突细胞核内,随时间其蛋白表达水平不同,这为HPV E6的树突细胞疫苗发挥有效的抗癌作用提供理论依据。