Name: efficient recombinant parvovirus production with the help of adenovirus-derived systems
Uploaded: 2012-04-23T12:00:00
Description: Watch this Scientific Journal Video about Efficient Recombinant Parvovirus Production with the Help of Adenovirus-derived Systems at JoVE.com

我々は、特定のマーカス·ミュラー、シルビアミュンスターマン、バーバラLiebetrau、とマンディロッシャーで、DKFZウイルスの生産と開発部のチームに感謝しています。本研究では、部分的に教育研究（BMBF）とドイツKrebsforschungszentrum /Cancéropôleデュグランドエスト応用腫瘍ウイルスの共同プログラムの枠組みの中で、ヘルムホルツ協会の連邦省からの補助金によって支えられてきた。

バイオセーフティーレベル2実験室、組換えパルボウイルス（recPV）の生産に必要とされることに注意してください。 プロトコルは、主に2つの部分に分割されます。最初の部分（トランスフェクションを介してrecPVの生産）プロトコルの2番目の部分（感染症を介してrecPVsの生産）に接種としてrecPVs最小限の量を生成する必要があります。一度recPVs少量のプロトコルの最初?...

<ol>
	<li>Cotmore, S. F., Tattersall, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parvoviral+host+range+and+cell+entry+mechanisms.">Parvoviral host range and cell entry mechanisms.</a> Adv. Virus. Res. 70, 183 (2007).</li><li>Rommelaere, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oncolytic+parvoviruses+as+cancer+therapeutics.">Oncolytic parvoviruses as cancer therapeutics.</a> Cytokine Growth Factor Rev. 21, 185 (2010).</li><li>Hristov, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Through+Its+Nonstructural+Protein+NS1,+Parvovirus+H-1+Induces+Apoptosis+via+Accumulation+of+Reactive+Oxygen+Species.">Through Its Nonstructural Protein NS1, Parvovirus H-1 Induces Apoptosis via Accumulation of Reactive Oxygen Species.</a> J. Virol. 84, 5909-5909 (2010).</li><li>Cornelis, J. J., Salome, N., Dinsart, C., Rommelaere, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vectors+based+on+autonomous+parvoviruses:+novel+tools+to+treat+cancer.">Vectors based on autonomous parvoviruses: novel tools to treat cancer.</a> J. Virol. 6, 193-193 (2004).</li><li>El-Andaloussi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+adenovirus-based+helper+system+to+support+production+of+recombinant+parvovirus.">Novel adenovirus-based helper system to support production of recombinant parvovirus.</a> Cancer Gene Ther. 18, (2011).</li><li>Kestler, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=cis+requirements+for+the+efficient+production+of+recombinant+DNA+vectors+based+on+autonomous+parvoviruses.">cis requirements for the efficient production of recombinant DNA vectors based on autonomous parvoviruses.</a> Hum. Gene. Ther. 10, 1619-1619 (1999).</li><li>Xiao, X., Li, J., Samulski, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+high-titer+recombinant+adeno-associated+virus+vectors+in+the+absence+of+helper+adenovirus.">Production of high-titer recombinant adeno-associated virus vectors in the absence of helper adenovirus.</a> J. Virol. 72, 2224 (1998).</li><li>He, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simplified+system+for+generating+recombinant+adenoviruses.">A simplified system for generating recombinant adenoviruses.</a> Proc. Natl. Acad. Sci. U.S.A. 95, 2509 (1998).</li><li>Zolotukhin, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recombinant+adeno-associated+virus+purification+using+novel+methods+improves+infectious+titer+and+yield.">Recombinant adeno-associated virus purification using novel methods improves infectious titer and yield.</a> Gene. Ther. 6, 973 (1999).</li><li>Maxwell, F., Harrison, G. S., Maxwell, I. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+production+of+recombinant+AAV+by+transient+transfection+of+NB324K+cells+using+electroporation.">Improved production of recombinant AAV by transient transfection of NB324K cells using electroporation.</a> J. Virol. Methods. 63, 129 (1997).</li><li>Wrzesinski, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chimeric+and+pseudotyped+parvoviruses+minimize+the+contamination+of+recombinant+stocks+with+replication-competent+viruses+and+identify+a+DNA+sequence+that+restricts+parvovirus+H-1+in+mouse+cells.">Chimeric and pseudotyped parvoviruses minimize the contamination of recombinant stocks with replication-competent viruses and identify a DNA sequence that restricts parvovirus H-1 in mouse cells.</a> J. Virol. 77, 3851 (2003).</li></ol>

我々はrecPV生産はアデノウイルスゲノムの要素の存在によって増強することができることを示している。私達はでrecPVとの組み合わせでトランスフェクションを介してアデノウイルスゲノムの要素を提供することによって、およびAd-VP-ヘルパーと100以上の倍の共感染細胞による10以上の倍（0.3から5 TU /セルから）でrecPV収率を増加している従来のプロトコルとの比較。ここで説明するプロトコ?...

<table border="1"><tbody><tr><td> 試薬の名前 </td><td> 会社 </td><td> カタログ番号 </td></tr><tr><td> DMEM </td><td>シグマ</td><td> D5796 </td></tr><tr><td> MEM </td><td>シグマ</td><td> M4655 </td></tr><tr><td>胎児ウシ血清</td><td> PAA </td><td> A15-101 </td></tr><tr><td> L-グルタミン</td><td>ギブコ</td><td> 25030-024 </td></tr><tr><td>トランスフェクション</td><td>ロシュ社</td><td> 047097050001 </td></tr><tr><td>トリプシン-EDTA </td><td>インビトロジェン</td><td> 25300062 </td></tr><tr><td>ベンゾナーゼヌクレアーゼ</td><td>シグマ</td><td>操作するもの</td></tr><tr><td>アデノ-X迅速タイターキット</td><td>クロンテック</td><td> 632250 </td></tr></tbody></table>

efficient recombinant parvovirus production with the help of adenovirus-derived systems

例えばラットH-1PVとMVMなどの齧歯類パルボウイルスは、（PV）、小さな正二十面体、一本鎖のDNAウイルスである。それらのゲノムは、それぞれ1非構造（NS1とNS2）とカプシド蛋白（VP1およびVP2）の発現を調節する2つのプロモーターP4とP38が含まれています。人間の2の非病原性でありながら、彼らは腫瘍溶解性とoncosuppressive能力のための抗癌剤として高い関心を集めている。 NS1は、ウイルスの細胞毒性3の主要なエフェクターである。さらに彼らの自然な抗腫瘍活性を高めるために、これらのベクトルからの誘導体は、治療遺伝子（ 例えば、細胞毒性ポリペプチド、サイトカイン、ケモカイン、腫瘍抑制遺伝子等）4とキャプシド蛋白質をコードする遺伝子を置換することによって生成されました。組換えパルボウイルス（recPVs）ベクターはウイルスDNAの増幅およびパッケージングするために必要なNS1 / 2コード配列とPVゲノムのテロメアを維持します。の生産recPVsはVPタンパク質（ 図1）4をコードする遺伝子を発現する第二のベクター（のpCMV-VP）で細胞を共トランスフェクトすることにより、プロデューサー細胞（一般にHEK293T）でのみ発生します。この方法で生成されたrecPVベクターは、複製欠損である。 recPVsは、それらが生成された元の親ウイルスに対する強化されたoncotoxic活性を有することがわかっていますが、それらの生産が主要な課題であると強く抗がん剤の臨床応用におけるこれらの薬剤の使用を妨げます。 我々は、使用中の他のプロトコルと比較してより10倍recPVsの生産を向上させたHEK293TにE2A、E4（ORF6）とVA RNA遺伝子（ 例えば pXX6プラスミド）を含むAD-5由来ベクターの導入は見つかりました。この知見に基づいて、我々はrecPVs生産などparvovirを強化するために必要なゲノムのアデノウイルスの要素を含む小説広告-VP-ヘルパーを構築した私達VP遺伝子ユニット5。広告-VP-ヘルパーの使用は、可能な限り（ 例えば NB324K）トランスフェクションが困難な細胞株を利用して、ウイルス感染の手順（のようなプラスミドトランスフェクションとは対照的に）に完全に依存するプロトコルを使用して、REC-PVの生産を可能にする（ 図2）。我々は非常に最終製品の5の品質に影響を与えることなく、生産時間とコストの両方を削減し、産生された組換えウイルスの量を向上させる手法を提案する。さらに、recPVの大規模生産は（浮遊細胞とバイオリアクター）で現在考えられる。

Watch this Scientific Journal Video about Efficient Recombinant Parvovirus Production with the Help of Adenovirus-derived Systems at JoVE.com

Efficient Recombinant Parvovirus Production with the Help of Adenovirus-derived Systems

ここでは、使用中の他のプロトコルに比べて100倍以上の組換えパルボウイルスの生産効率を向上させる細胞の感染に基づいて、プロトコルを記述します。このプロトコルは、パルボウイルスのVP転写ユニット（AD-VP）を含む新規のアデノウイルス5ベースのヘルパーの使用に依存しています。

アデノウイルス由来のシステムの助けを借りて効率的な組換えパルボウイルスの生産

Rodent parvoviruses (PV) such as rat H-1PV and MVM, are small icosahedral, single stranded, DNA viruses. Their genome includes two promoters P4 and P38 ...

efficient-recombinant-parvovirus-production-with-help-adenovirus

Research

JoVE Journal

Immunology and Infection

Estimating Virus Production Rates in Aquatic Systems

Viruses are pervasive components of marine and freshwater systems, and are known to be significant agents of microbial mortality. Developing quantitative estimates of this process is critical as we can then develop better models of microbial community structure and function as well as advance our understanding of how viruses work to alter aquatic biogeochemical cycles. The virus reduction technique allows researchers to estimate the rate at which virus particles are released from the endemic microbial community. In brief, the abundance of free (extracellular) viruses is reduced in a sample while the microbial community is maintained at near ambient concentration. The microbial community is then incubated in the absence of free viruses and the rate at which viruses reoccur in the sample (through the lysis of already infected members of the community) can be quantified by epifluorescence microscopy or, in the case of specific viruses, quantitative PCR. These rates can then be used to estimate the rate of microbial mortality due to virus-mediated cell lysis.

The turnover rate of viruses in marine and freshwater systems can be estimated by a reduction and reoccurrence technique. The data allow researchers to infer rates of virus-mediated microbial mortality in aquatic systems.

水系でのウイルス産生率を予測

Viruses are pervasive components of marine and freshwater systems, and are known to be significant agents of microbial mortality. Developing quantitative ...

免疫・感染学

Recombinant Retroviral Production and Infection of B Cells

The transgenic expression of genes in eukaryotic cells is a powerful reverse genetic approach in which a gene of interest is expressed under the control of a heterologous expression system to facilitate the analysis of the resulting phenotype. This approach can be used to express a gene that is not normally found in the organism, to express a mutant form of a gene product, or to over-express a dominant-negative form of the gene product. It is particularly useful in the study of the hematopoetic system, where transcriptional regulation is a major control mechanism in the development and differentiation of B cells 1, reviewed in 2-4.
Mouse genetics is a powerful tool for the study of human genes and diseases. A comparative analysis of the mouse and human genome reveals conservation of synteny in over 90% of the genome 5. Also, much of the technology used in mouse models is applicable to the study of human genes, for example, gene disruptions and allelic replacement 6. However, the creation of a transgenic mouse requires a great deal of resources of both a financial and technical nature. Several projects have begun to compile libraries of knock out mouse strains (KOMP, EUCOMM, NorCOMM) or mutagenesis induced strains (RIKEN), which require large-scale efforts and collaboration 7. Therefore, it is desirable to first study the phenotype of a desired gene in a cell culture model of primary cells before progressing to a mouse model. 
Retroviral DNA integrates into the host DNA, preferably within or near transcription units or CpG islands, resulting in stable and heritable expression of the packaged gene of interest while avoiding transcriptional silencing 8 9. The genes are then transcribed under the control of a high efficiency retroviral promoter, resulting in a high efficiency of transcription and protein production. Therefore, retroviral expression can be used with cells that are difficult to transfect, provided the cells are in an active state during mitosis. Because the structural genes of the virus are contained within the packaging cell line, the expression vectors used to clone the gene of interest contain no structural genes of the virus, which both eliminates the possibility of viral revertants and increases the safety of working with viral supernatants as no infectious virions are produced 10. 
Here we present a protocol for recombinant retroviral production and subsequent infection of splenic B cells. After isolation, the cultured splenic cells are stimulated with Th derived lymphokines and anti-CD40, which induces a burst of B cell proliferation and differentiation 11. This protocol is ideal for the study of events occurring late in B cell development and differentiation, as B cells are isolated from the spleen following initial hematopoetic events but prior to antigenic stimulation to induce plasmacytic differentiation.

An efficient system of structure and function analysis of a gene in an ex vivo culture of splenic B-lymphocytes is described. This method takes advantage of recombinant retroviral production in a helper free, ecotrophic packaging cell line. Stable, heritable expression of a gene of interest within primary lymphocytes is achieved leading to generation of surface antibodies on B cells undergoing class switch recombination.

B細胞の組換えレトロウイルスの生産と感染症

The transgenic expression of genes in eukaryotic cells is a powerful reverse genetic approach in which a gene of interest is expressed under the control ...

Optimized Protocol for Efficient Transfection of Dendritic Cells without Cell Maturation

Dendritic cells (DCs) can be considered sentinels of the immune system which play a critical role in its initiation and response to infection1. Detection of pathogenic antigen by na&iuml;ve DCs is through pattern recognition receptors (PRRs) which are able to recognize specific conserved structures referred to as pathogen-associated molecular patterns (PAMPS). Detection of PAMPs by DCs triggers an intracellular signaling cascade resulting in their activation and transformation to mature DCs. This process is typically characterized by production of type 1 interferon along with other proinflammatory cytokines, upregulation of cell surface markers such as MHCII and CD86 and migration of the mature DC to draining lymph nodes, where interaction with T cells initiates the adaptive immune response2,3. Thus, DCs link the innate and adaptive immune systems. 
The ability to dissect the molecular networks underlying DC response to various pathogens is crucial to a better understanding of the regulation of these signaling pathways and their induced genes. It should also help facilitate the development of DC-based vaccines against infectious diseases and tumors. However, this line of research has been severely impeded by the difficulty of transfecting primary DCs4.
Virus transduction methods, such as the lentiviral system, are typically used, but carry many limitations such as complexity and bio-hazardous risk (with the associated costs)5,6,7,8. Additionally, the delivery of viral gene products increases the immunogenicity of those transduced DCs9,10,11,12. Electroporation has been used with mixed results13,14,15, but we are the first to report the use of a high-throughput transfection protocol and conclusively demonstrate its utility.
In this report we summarize an optimized commercial protocol for high-throughput transfection of human primary DCs, with limited cell toxicity and an absence of DC maturation16. Transfection efficiency (of GFP plasmid) and cell viability were more than 50% and 70% respectively. FACS analysis established the absence of increase in expression of the maturation markers CD86 and MHCII in transfected cells, while qRT-PCR demonstrated no upregulation of IFN&beta;. Using this electroporation protocol, we provide evidence for successful transfection of DCs with siRNA and effective knock down of targeted gene RIG-I, a key viral recognition receptor16,17, at both the mRNA and protein levels.

We present our optimized high-throughput nucleofection protocol as an efficient way of transfecting primary human monocyte-derived dendritic cells with either plasmid DNA or siRNA without causing cell maturation. We further provide evidence for successful siRNA silencing of targeted gene RIG-I at both the mRNA and protein levels.

細胞の成熟せずに樹状細胞の効率的なトランスフェクションに最適化されたプロトコル

Dendritic cells (DCs) can be considered sentinels of the immune system which play a critical role in its initiation and response to infection1. Detection ...

Production and Titering of Recombinant Adeno-associated Viral Vectors

In recent years recombinant adeno-associated viral vectors (AAV) have become increasingly valuable for in vivo studies in animals, and are also currently being tested in human clinical trials. Wild-type AAV is a non-pathogenic member of the parvoviridae family and inherently replication-deficient. The broad transduction profile, low immune response as well as the strong and persistent transgene expression achieved with these vectors has made them a popular and versatile tool for in vitro and in vivo gene delivery. rAAVs can be easily and cheaply produced in the laboratory and, based on their favourable safety profile, are generally given a low safety classification. Here, we describe a method for the production and titering of chimeric rAAVs containing the capsid proteins of both AAV1 and AAV2. The use of these so-called chimeric vectors combines the benefits of both parental serotypes such as high titres stocks (AAV1) and purification by affinity chromatography (AAV2). These AAV serotypes are the best studied of all AAV serotypes, and individually have a broad infectivity pattern. The chimeric vectors described here should have the infectious properties of AAV1 and AAV2 and can thus be expected to infect a large range of tissues, including neurons, skeletal muscle, pancreas, kidney among others. The method described here uses heparin column purification, a method believed to give a higher viral titer and cleaner viral preparation than other purification methods, such as centrifugation through a caesium chloride gradient. Additionally, we describe how these vectors can be quickly and easily titered to give accurate reading of the number of infectious particles produced.

Recombinant adeno-associated virus (rAAVs) vectors are becoming increasingly valuable for in vivo studies in animals. We describe how rAAVs can be produced in the laboratory and how these vectors can be titered to give an accurate reading of the number of infectious particles produced.

組換えアデノ随伴ウイルスベクターの産生と力価測定

In recent years recombinant adeno-associated viral vectors (AAV) have become increasingly valuable for in vivo studies in animals, and are also currently ...

Scalable High Throughput Selection From  Phage-displayed Synthetic Antibody Libraries

The demand for antibodies that fulfill the needs of both basic and clinical research applications is high and will dramatically increase in the future. However, it is apparent that traditional monoclonal technologies are not alone up to this task. This has led to the development of alternate methods to satisfy the demand for high quality and renewable affinity reagents to all accessible elements of the proteome. Toward this end, high throughput methods for conducting selections from phage-displayed synthetic antibody libraries have been devised for applications involving diverse antigens and optimized for rapid throughput and success. Herein, a protocol is described in detail that illustrates with video demonstration the parallel selection of Fab-phage clones from high diversity libraries against hundreds of targets using either a manual 96 channel liquid handler or automated robotics system. Using this protocol, a single user can generate hundreds of antigens, select antibodies to them in parallel and validate antibody binding within 6-8 weeks. Highlighted are: i) a viable antigen format, ii) pre-selection antigen characterization, iii) critical steps that influence the selection of specific and high affinity clones, and iv) ways of monitoring selection effectiveness and early stage antibody clone characterization. With this approach, we have obtained synthetic antibody fragments (Fabs) to many target classes including single-pass membrane receptors, secreted protein hormones, and multi-domain intracellular proteins. These fragments are readily converted to full-length antibodies and have been validated to exhibit high affinity and specificity. Further, they have been demonstrated to be functional in a variety of standard immunoassays including Western blotting, ELISA, cellular immunofluorescence, immunoprecipitation and related assays. This methodology will accelerate antibody discovery and ultimately bring us closer to realizing the goal of generating renewable, high quality antibodies to the proteome.

A method is described with visual accompaniment for conducting scalable, high throughput selections from phage-displayed combinatorial synthetic antibody libraries against hundreds of antigens simultaneously. Using this parallel approach, we have isolated antibody fragments that exhibit high affinity and specificity for diverse antigens that are functional in standard immunoassays.

ファージディスプレイされた合成抗体ライブラリーから、スケーラブルな高スループットの選択

The demand for antibodies that fulfill the needs of both basic and clinical research applications is high and will dramatically increase in the future. ...

Simple and Efficient Production and Purification of Mouse Myelin Oligodendrocyte Glycoprotein for Experimental Autoimmune Encephalomyelitis Studies

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), thought to occur as a result of autoimmune responses targeting myelin. Experimental autoimmune encephalomyelitis (EAE) is the most common animal model of CNS autoimmune disease, and is typically induced via immunization with short peptides representing immunodominant CD4+ T cell epitopes of myelin proteins. However, B cells recognize unprocessed protein directly, and immunization with short peptide does not activate B cells that recognize the native protein. As recent clinical trials of B cell-depleting therapies in MS have suggested a role for B cells in driving disease in humans, there is an urgent need for animal models that incorporate B cell-recognition of autoantigen. To this end, we have generated a new fusion protein containing the extracellular domain of the mouse version of myelin oligodendrocyte glycoprotein (MOG) as well as N-terminal fusions of a His-tag for purification purposes and the thioredoxin protein to improve solubility (MOGtag). A tobacco etch virus (TEV) protease cleavage site was incorporated to allow the removal of all tag sequences, leaving only the pure MOG1-125 extracellular domain. Here, we describe a simple protocol using only standard laboratory equipment to produce large quantities of pure MOGtag or MOG1-125. This protocol consistently generates over 200 mg of MOGtag protein. Immunization with either MOGtag or MOG1-125 generates an autoimmune response that includes pathogenic B cells that recognize the native mouse MOG.

We describe a simple protocol using only basic lab equipment to generate and purify large quantities of a fusion protein that contains mouse Myelin Oligodendrocyte Glycoprotein. This protein can be used to induce experimental autoimmune encephalomyelitis driven by both T and B cells.

実験的自己免疫性脳脊髄炎研究のためのシンプルで効率的な生産とマウスミエリンオリゴデンドロサイト糖タンパク質の精製

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), thought to occur as a result of autoimmune responses ...

Analysis of Lymphocyte Extravasation Using an In Vitro Model of the Human Blood-brain Barrier

Lymphocyte extravasation into the central nervous system (CNS) is critical for immune surveillance. Disease-related alterations of lymphocyte extravasation might result in pathophysiological changes in the CNS. Thus, investigation of lymphocyte migration into the CNS is important to understand inflammatory CNS diseases and to develop new therapy approaches. Here we present an in vitro model of the human blood-brain barrier to study lymphocyte extravasation. Human brain microvascular endothelial cells (HBMEC) are confluently grown on a porous polyethylene terephthalate transwell insert to mimic the endothelium of the blood-brain barrier. Barrier function is validated by zonula occludens immunohistochemistry, transendothelial electrical resistance (TEER) measurements as well as analysis of evans blue permeation. This model allows investigation of the diapedesis of rare lymphocyte subsets such as CD56brightCD16dim/- NK cells. Furthermore, the effects of other cells, cytokines and chemokines, disease-related alterations, and distinct treatment regimens on the migratory capacity of lymphocytes can be studied. Finally, the impact of inflammatory stimuli as well as different treatment regimens on the endothelial barrier can be analyzed.

Analysis of Lymphocyte Extravasation Using an In Vitro Model of the Human Blood-brain Barrier

Here, we describe a human blood-brain barrier model enabling to investigate lymphocyte transmigration into the central nervous system in vitro.

使用してリンパ球血管外漏出の分析<em&gt;インビトロ</em&gt;ヒト血液脳関門のモデル

Lymphocyte extravasation into the central nervous system (CNS) is critical for immune surveillance. Disease-related alterations of lymphocyte ...

Detection and Removal of Nuclease Contamination During Purification of Recombinant Prototype Foamy Virus Integrase

The integrase (IN) protein of the retrovirus prototype foamy virus (PFV) is a model enzyme for studying the mechanism of retroviral integration. Compared to IN from other retroviruses, PFV IN is more soluble and more amenable to experimental manipulation. Additionally, it is sensitive to clinically relevant human immunodeficiency virus (HIV-1) IN inhibitors, suggesting that the catalytic mechanism of PFV IN is similar to that of HIV-1 IN. IN catalyzes the covalent joining of viral complementary DNA (cDNA) to target DNA in a process called strand transfer. This strand transfer reaction introduces nicks to the target DNA. Analysis of integration reaction products can be confounded by the presence of nucleases that similarly nick DNA. A bacterial nuclease has been shown to co-purify with recombinant PFV IN expressed in Escherichia coli (E. coli). Here we describe a method to isolate PFV IN from the contaminating nuclease by heparin affinity chromatography. Fractions are easily screened for nuclease contamination with a supercoiled plasmid and agarose gel electrophoresis. PFV IN and the contaminating nuclease display alternative affinities for heparin sepharose allowing a nuclease-free preparation of recombinant PFV IN suitable for bulk biochemical or single molecule analysis of integration.

Recombinant prototype foamy virus integrase protein is often contaminated with a bacterial nuclease during purification. This method identifies nuclease contamination and removes it from the final preparation of the enzyme.

組換えプロトタイプ フォーミー ウイルス インテグラーゼの浄化中にヌクレアーゼの混入の検出と除去

The integrase (IN) protein of the retrovirus prototype foamy virus (PFV) is a model enzyme for studying the mechanism of retroviral integration. Compared ...

Generating Recombinant Avian Herpesvirus Vectors with CRISPR/Cas9 Gene Editing

Herpesvirus of turkeys (HVT) is an ideal viral vector for the generation of recombinant vaccines against a number of avian diseases, such as avian influenza (AI), Newcastle disease (ND), and infectious bursal disease (IBD), using bacterial artificial chromosome (BAC) mutagenesis or conventional recombination methods. The clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 system has been successfully used in many settings for gene editing, including the manipulation of several large DNA virus genomes. We have developed a rapid and efficient CRISPR/Cas9-mediated genome editing pipeline to generate recombinant HVT. To maximize the potential use of this method, we present here detailed information about the methodology of generating recombinant HVT expressing the VP2 protein of IBDV. The VP2 expression cassette is inserted into the HVT genome via an NHEJ (nonhomologous end-joining)-dependent repair pathway. A green fluorescence protein (GFP) expression cassette is first attached to the insert for easy visualization and then removed via the Cre-LoxP system. This approach offers an efficient way to introduce other viral antigens into the HVT genome for the rapid development of recombinant vaccines.

Herpesvirus of turkeys (HVT) is widely used as a vector platform for the generation of recombinant vaccines against a number of avian diseases. This article describes a simple and rapid approach for the generation of recombinant HVT-vectored vaccines using an integrated NHEJ-CRISPR/Cas9 and Cre-Lox system.

CRISPR/Cas9 組換え鳥ヘルペス ウイルスのベクトルを生成する遺伝子の編集

Herpesvirus of turkeys (HVT) is an ideal viral vector for the generation of recombinant vaccines against a number of avian diseases, such as avian ...

Measurement of Specific Mycobacterial Mistranslation Rates with Gain-of-function Reporter Systems

The translation of genes into proteins is prone to errors. Although the average rate of translational error in model systems is estimated to be 1/10,000 per codon, the actual error rates vary widely, depending on the species, environment, and codons being studied. We have previously shown that mycobacteria use a two-step pathway for the generation of aminoacylated glutamine and asparagine tRNAs and that this is specifically associated with relatively high error rates due to the modulation of mistranslation rates by an essential component of the pathway, the amidotransferase GatCAB. We modified a previously employed Renilla-Firefly dual-luciferase system that had been used to measure mistranslation rates in Escherichia coli for use in mycobacteria to measure specific mistranslation rates of glutamate at glutamine codons and aspartate for asparagine codons. Although this reporter system was suitable for the accurate estimation of specific error rates, lack of sensitivity and requirements for excessive manipulation steps made it unsuitable for high-throughput applications. Therefore, we developed a second gain-of-function reporter system, using Nluc luciferase and green fluorescent protein (GFP), which is more amenable to medium/high-throughput settings. We used this system to identify kasugamycin as a small molecule that can decrease mycobacterial mistranslation. Although the reporters that we describe here have been used to measure specific types of mycobacterial mistranslation, they may be modified to measure other types of mistranslation in a number of model systems.

In this article, we present two complementary methods to measure specific rates of translational error and mistranslation in the model mycobacterium, Mycobacterium smegmatis, using gain-of-function reporter systems. The methods can be employed to measure accurate error rates in low throughput or relative error rates in a more high-throughput setting.

機能向上レポーター・システムによる特異的マイコバクテリア・誤訳率の測定

The translation of genes into proteins is prone to errors. Although the average rate of translational error in model systems is estimated to be 1/10,000 ...