We previously constructed a herpes simplex virus 1(HSV-1) UL7 mutant virus(M1) and showed that a partial deletion mutation of the UL7 gene led to a lower proliferative rate and an attenuated phenotype. Using the M1 mu...We previously constructed a herpes simplex virus 1(HSV-1) UL7 mutant virus(M1) and showed that a partial deletion mutation of the UL7 gene led to a lower proliferative rate and an attenuated phenotype. Using the M1 mutant, we further modified the UL41 gene, which encodes another tegument protein, and the latency-associated transcript(LAT) gene. Observations of the resulting mutants with modified UL7 and UL41(M2) or UL7, UL41 and LAT(M3) genes indicated attenuated phenotypes, with lower proliferative ratios in various cells, non-lethal infections in mice and lower viral loads in nervous tissues compared with the wild-type strain. Furthermore, no LAT stable intron could be detected in the trigeminal ganglion of M3-infected animals. The results obtained with the three HSV-1 mutants indicate that the M3 mutant is an attenuated strain with low pathogenicity during both acute and latent infections. Together, the results support the use of the M3 mutant as a candidate for the development of an HSV-1 vaccine.展开更多
Various factors/pathways including hormonal regulation have been suggested to control herpes simplex virus type 1 （HSV-1） latency and reactivation. Our computer analysis identified a DNA repeat containing thyroid ho...Various factors/pathways including hormonal regulation have been suggested to control herpes simplex virus type 1 （HSV-1） latency and reactivation. Our computer analysis identified a DNA repeat containing thyroid hormoneresponsive elements （TRE） in the regulatory region of HSV-1 latency-associated transcript （LAT）. Thyroid hormone （triiodothyronine, T3） functions via its receptor TR （thyroid hormone receptor）, a transcription factor. Present study investigated the roles of TR and T3 in HSV-1 gene expression using cultured neuoroblastoma cell lines. We demonstrated that liganded TR activated LAT transcription, but repressed infected cell protein no. 0 （ICP0） transcription in the presence of LAT TRE. Chromatin immunoprecipitation （CHIP） assays showed that TRs were recruited to LAT TREs independently of T3 and hyperacetylated H4 was associated with the LAT promoter that was transcriptionally active. In addition, ChIP results showed that the chromatin insulator protein CCCTC-binding factor was enriched at the LAT TREs in the presence of TR and T3. In addition, the BRG1 chromatin remodeling complex is found to participate in the T3/TR-mediated LAT activation since overexpression of BRG1 enhanced the LAT transcription and the dominant-negative mutant K785R abolished the activation. This is the first report revealing that TR elicits epigenetic regulation on HSV-1 ICP0 expression in neuronal cells and could have a role in the complex processes of HSV-1 latency/reactivation.展开更多
We measured erodibility and mean weight diameter （MWD） of soil aggregates in different parts of a forest road. Samples of topsoil were collected from cutslope, fillslope, road surface and forest ground to assess the...We measured erodibility and mean weight diameter （MWD） of soil aggregates in different parts of a forest road. Samples of topsoil were collected from cutslope, fillslope, road surface and forest ground to assess the texture, bulk density, moisture, CaCO3 and organic matter. Soil aggregate stability was determined by wet sieving. Soil erodibility on the road surface was 2.3 and 1.3 times higher than on the fillslope and cutslope, respectively. The forest soil had the lowest erodibility. Aggregate stability of cutslope and road surface were low and very low, respectively. There was a significant negative relationship between cutslope erodibility with CaCO3 and sand content. Cutslope erodibility increased with increasing silt, clay and moisture content. On fillslopes, MWD increased with in-creasing rock fragment cover, plant cover, litter cover, organic matter and sand. There was a strong negative correlation between fillslope erodibility and organic matter, sand and MWD. There was no significant difference between erodibility of bare soil and soils beneathRubus hyrcanusL. and Philonotis marchica （Hedw.） Brid.展开更多
目的:研究CD59分子在LAT(Linker for activated T cells)介导的T系淋巴细胞活化中所起的作用。方法:构建LAT-GFP融合蛋白,以逆转录病毒为载体转染Jurkat细胞,建立稳定转染细胞株(Jurkat-GFP)。分别使用CD59抗体刺激和pSUPER-siCD59干扰...目的:研究CD59分子在LAT(Linker for activated T cells)介导的T系淋巴细胞活化中所起的作用。方法:构建LAT-GFP融合蛋白,以逆转录病毒为载体转染Jurkat细胞,建立稳定转染细胞株(Jurkat-GFP)。分别使用CD59抗体刺激和pSUPER-siCD59干扰质粒(GFP标记)沉默Jurkat-GFP细胞。免疫荧光观察CD59和LAT分子在细胞膜的表达和定位;MTT比色法检测细胞增殖率的变化;Western blot检测LAT活化信号转导通路中相关蛋白分子磷酸化水平。结果:荧光显微镜下可见Jurkat-GFP细胞绿色荧光表达于细胞膜,转染干扰质粒后细胞膜和细胞质均有绿色荧光表达。激光共聚焦显微镜下可见CD59抗体刺激前CD59和LAT分子均匀分布于细胞膜,且转染干扰质粒的Jurkat-GFP细胞CD59表达量下降。CD59抗体刺激后CD59分子和LAT分子点状聚集共定位于细胞膜。MTT结果表明相对于正常Jurkat-GFP细胞,抗体活化后细胞增殖速率明显升高(P>0.05),而电转干扰质粒后细胞生长减慢。Western blot结果表明,CD59抗体刺激后细胞ZAP-70、LCK、PLC-r总蛋白表达无明显差异(P>0.05),而磷酸化蛋白表达显著增高(P<0.05)。结论:抗体活化后细胞膜上CD59和LAT分子聚集并共定位于细胞膜,且细胞信号转导通路下游分子磷酸化水平增高,进一步证实CD59分子经抗体活化后可促进LAT介导的T细胞信号转导。展开更多
目的:构建增强型绿色荧光蛋白(EGFP)与T细胞衔接活化因子(Linker for activated of T cells,LAT)融合蛋白的真核表达载体,观测LAT-EGFP在Jurkat细胞中的定位表达。方法:利用RT-PCR技术提取并扩增LAT除去终止密码子外的全部序列,克隆到...目的:构建增强型绿色荧光蛋白(EGFP)与T细胞衔接活化因子(Linker for activated of T cells,LAT)融合蛋白的真核表达载体,观测LAT-EGFP在Jurkat细胞中的定位表达。方法:利用RT-PCR技术提取并扩增LAT除去终止密码子外的全部序列,克隆到真核表达载体PEGFP-N3,酶切鉴定并测序。瞬时转染到Jurkat细胞中进行表达,荧光共聚焦显微镜观察LAT-EGFP在Jurkat细胞中的表达及细胞定位。提取转染后细胞总RNA,通过RT-PCR的方法检测LAT-EGFP在转录水平的表达。利用Western blot法进一步鉴定融合蛋白的表达。结果:重组载体经酶切鉴定,切出片段长度在750 bp左右与插入序列长度相符,并进一步进行测序鉴定证实连接完全正确。共聚焦显微镜观察表达的LAT-EGFP融合蛋白定位在细胞膜上,并呈点簇状聚集状态。RT-PCR扩增证实了LAT和EGFP的融合蛋白在Jurkat细胞中在转录水平的表达,Western blot分析进一步证明了LAT和EGFP融合蛋白构建成功,并在蛋白水平上有明显的融合表达。结论:成功构建真核表达载体LAT-EGFP,且融合蛋白LAT-EGFP与野生型LAT在Jurkat细胞中的定位一致,具有功能表达效应,这为后续准确研究具有棕榈酰化位点的跨膜接头蛋白的信号转导作用提供了一种良好的研究载体和方法。展开更多
基金supported by the National Basic Research Program (2012CB518901)Chinese academy of medical sciences (CAMS) Initiative for Innovative Medicine (2016I2M-1-019)+1 种基金the National Natural Science Foundation of China (31300143, 31100127)the Fundamental Research Funds for the Central Universities (2016ZX310047, 2016ZX350072)
文摘We previously constructed a herpes simplex virus 1(HSV-1) UL7 mutant virus(M1) and showed that a partial deletion mutation of the UL7 gene led to a lower proliferative rate and an attenuated phenotype. Using the M1 mutant, we further modified the UL41 gene, which encodes another tegument protein, and the latency-associated transcript(LAT) gene. Observations of the resulting mutants with modified UL7 and UL41(M2) or UL7, UL41 and LAT(M3) genes indicated attenuated phenotypes, with lower proliferative ratios in various cells, non-lethal infections in mice and lower viral loads in nervous tissues compared with the wild-type strain. Furthermore, no LAT stable intron could be detected in the trigeminal ganglion of M3-infected animals. The results obtained with the three HSV-1 mutants indicate that the M3 mutant is an attenuated strain with low pathogenicity during both acute and latent infections. Together, the results support the use of the M3 mutant as a candidate for the development of an HSV-1 vaccine.
文摘Various factors/pathways including hormonal regulation have been suggested to control herpes simplex virus type 1 （HSV-1） latency and reactivation. Our computer analysis identified a DNA repeat containing thyroid hormoneresponsive elements （TRE） in the regulatory region of HSV-1 latency-associated transcript （LAT）. Thyroid hormone （triiodothyronine, T3） functions via its receptor TR （thyroid hormone receptor）, a transcription factor. Present study investigated the roles of TR and T3 in HSV-1 gene expression using cultured neuoroblastoma cell lines. We demonstrated that liganded TR activated LAT transcription, but repressed infected cell protein no. 0 （ICP0） transcription in the presence of LAT TRE. Chromatin immunoprecipitation （CHIP） assays showed that TRs were recruited to LAT TREs independently of T3 and hyperacetylated H4 was associated with the LAT promoter that was transcriptionally active. In addition, ChIP results showed that the chromatin insulator protein CCCTC-binding factor was enriched at the LAT TREs in the presence of TR and T3. In addition, the BRG1 chromatin remodeling complex is found to participate in the T3/TR-mediated LAT activation since overexpression of BRG1 enhanced the LAT transcription and the dominant-negative mutant K785R abolished the activation. This is the first report revealing that TR elicits epigenetic regulation on HSV-1 ICP0 expression in neuronal cells and could have a role in the complex processes of HSV-1 latency/reactivation.
文摘We measured erodibility and mean weight diameter （MWD） of soil aggregates in different parts of a forest road. Samples of topsoil were collected from cutslope, fillslope, road surface and forest ground to assess the texture, bulk density, moisture, CaCO3 and organic matter. Soil aggregate stability was determined by wet sieving. Soil erodibility on the road surface was 2.3 and 1.3 times higher than on the fillslope and cutslope, respectively. The forest soil had the lowest erodibility. Aggregate stability of cutslope and road surface were low and very low, respectively. There was a significant negative relationship between cutslope erodibility with CaCO3 and sand content. Cutslope erodibility increased with increasing silt, clay and moisture content. On fillslopes, MWD increased with in-creasing rock fragment cover, plant cover, litter cover, organic matter and sand. There was a strong negative correlation between fillslope erodibility and organic matter, sand and MWD. There was no significant difference between erodibility of bare soil and soils beneathRubus hyrcanusL. and Philonotis marchica （Hedw.） Brid.
文摘目的:研究CD59分子在LAT(Linker for activated T cells)介导的T系淋巴细胞活化中所起的作用。方法:构建LAT-GFP融合蛋白,以逆转录病毒为载体转染Jurkat细胞,建立稳定转染细胞株(Jurkat-GFP)。分别使用CD59抗体刺激和pSUPER-siCD59干扰质粒(GFP标记)沉默Jurkat-GFP细胞。免疫荧光观察CD59和LAT分子在细胞膜的表达和定位;MTT比色法检测细胞增殖率的变化;Western blot检测LAT活化信号转导通路中相关蛋白分子磷酸化水平。结果:荧光显微镜下可见Jurkat-GFP细胞绿色荧光表达于细胞膜,转染干扰质粒后细胞膜和细胞质均有绿色荧光表达。激光共聚焦显微镜下可见CD59抗体刺激前CD59和LAT分子均匀分布于细胞膜,且转染干扰质粒的Jurkat-GFP细胞CD59表达量下降。CD59抗体刺激后CD59分子和LAT分子点状聚集共定位于细胞膜。MTT结果表明相对于正常Jurkat-GFP细胞,抗体活化后细胞增殖速率明显升高(P>0.05),而电转干扰质粒后细胞生长减慢。Western blot结果表明,CD59抗体刺激后细胞ZAP-70、LCK、PLC-r总蛋白表达无明显差异(P>0.05),而磷酸化蛋白表达显著增高(P<0.05)。结论:抗体活化后细胞膜上CD59和LAT分子聚集并共定位于细胞膜,且细胞信号转导通路下游分子磷酸化水平增高,进一步证实CD59分子经抗体活化后可促进LAT介导的T细胞信号转导。
文摘目的:构建增强型绿色荧光蛋白(EGFP)与T细胞衔接活化因子(Linker for activated of T cells,LAT)融合蛋白的真核表达载体,观测LAT-EGFP在Jurkat细胞中的定位表达。方法:利用RT-PCR技术提取并扩增LAT除去终止密码子外的全部序列,克隆到真核表达载体PEGFP-N3,酶切鉴定并测序。瞬时转染到Jurkat细胞中进行表达,荧光共聚焦显微镜观察LAT-EGFP在Jurkat细胞中的表达及细胞定位。提取转染后细胞总RNA,通过RT-PCR的方法检测LAT-EGFP在转录水平的表达。利用Western blot法进一步鉴定融合蛋白的表达。结果:重组载体经酶切鉴定,切出片段长度在750 bp左右与插入序列长度相符,并进一步进行测序鉴定证实连接完全正确。共聚焦显微镜观察表达的LAT-EGFP融合蛋白定位在细胞膜上,并呈点簇状聚集状态。RT-PCR扩增证实了LAT和EGFP的融合蛋白在Jurkat细胞中在转录水平的表达,Western blot分析进一步证明了LAT和EGFP融合蛋白构建成功,并在蛋白水平上有明显的融合表达。结论:成功构建真核表达载体LAT-EGFP,且融合蛋白LAT-EGFP与野生型LAT在Jurkat细胞中的定位一致,具有功能表达效应,这为后续准确研究具有棕榈酰化位点的跨膜接头蛋白的信号转导作用提供了一种良好的研究载体和方法。
