私たちは、フローサイトメトリーのヘルプのためにUTMBフローサイトメトリーコアファシリティのマウスポリクローナル抗RVFV抗血清とM.グリフィンを提供するためにRBテッシュに感謝します。サポートされていたこの作品は、NIHの助成金R01 AI08764301、優秀西部地域センターを通じて5 U54 AI057156によってサポートされていました、そしてUTMB.BKにおけるワクチン開発のためのシーリーセンターから資金がUTMB.OLでジェームズ·W·マクラフリンフェローシップ基金によってサポートされていましたモーリスR.ハイルマン早期キャリア調査官賞によって。

<ol>
	<li>Fakan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+support+for+RNA+synthesis+in+the+cell+nucleus.">Structural support for RNA synthesis in the cell nucleus.</a> Methods Achiev. Exp. Pathol. 12, 105-140 (1986).</li><li>Jensen, P. O., Larsen, J., Christiansen, J., Larsen, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow+cytometric+measurement+of+RNA+synthesis+using+bromouridine+labelling+and+bromodeoxyuridine+antibodies.">Flow cytometric measurement of RNA synthesis using bromouridine labelling and bromodeoxyuridine antibodies.</a> Cytometry. 14, 455-458 (1993).</li><li>Jao, C. Y., Salic, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exploring+RNA+transcription+and+turnover+in+vivo+by+using+click+chemistry.">Exploring RNA transcription and turnover in vivo by using click chemistry.</a> Proc. Natl. Acad. Sci. U.S.A. 105, 15779-15784 (2008).</li><li>Rostovtsev, V. V., Green, L. G., Fokin, V. V., Sharpless, K. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+stepwise+huisgen+cycloaddition+process:+copper(I)-catalyzed+regioselective+"ligation"+of+azides+and+terminal+alkynes.">A stepwise huisgen cycloaddition process: copper(I)-catalyzed regioselective "ligation" of azides and terminal alkynes.</a> Angew Chem. Int. Ed. Engl. 41, 2596-2599 (2002).</li><li>Tornoe, C. W., Christensen, C., Meldal, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peptidotriazoles+on+solid+phase:+[1,2,3]-triazoles+by+regiospecific+copper(i)-catalyzed+1,3-dipolar+cycloadditions+of+terminal+alkynes+to+azides.">Peptidotriazoles on solid phase: [1,2,3]-triazoles by regiospecific copper(i)-catalyzed 1,3-dipolar cycloadditions of terminal alkynes to azides.</a> J. Org. Chem. 67, 3057-3064 (2002).</li><li>Kalveram, B., Lihoradova, O., Ikegami, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NSs+protein+of+rift+valley+fever+virus+promotes+posttranslational+downregulation+of+the+TFIIH+subunit+p62.">NSs protein of rift valley fever virus promotes posttranslational downregulation of the TFIIH subunit p62.</a> J. Virol. 85, 6234-6243 (2011).</li><li>Kalveram, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rift+Valley+fever+virus+NSs+inhibits+host+transcription+independently+of+the+degradation+of+dsRNA-dependent+protein+kinase+PKR.">Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent protein kinase PKR.</a> Virology. , (2012).</li><li>Head, J. A., Kalveram, B., Ikegami, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+analysis+of+Rift+Valley+fever+virus+NSs+encoding+a+partial+truncation.">Functional analysis of Rift Valley fever virus NSs encoding a partial truncation.</a> PLoS One. 7, e45730 (2012).</li><li>Lihoradova, O. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+Rift+Valley+Fever+Virus+MP-12+Strain+Encoding+NSs+of+Punta+Toro+Virus+or+Sandfly+Fever+Sicilian+Virus.">Characterization of Rift Valley Fever Virus MP-12 Strain Encoding NSs of Punta Toro Virus or Sandfly Fever Sicilian Virus.</a> PLoS Negl Trop Dis. 7, e2181 (2013).</li><li>Kalveram, B., Ikegami, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toscana+Virus+NSs+Protein+Promotes+Degradation+of+Double-Stranded+RNA-Dependent+Protein+Kinase.">Toscana Virus NSs Protein Promotes Degradation of Double-Stranded RNA-Dependent Protein Kinase.</a> J. Virol. , (2013).</li><li>Schmaljohn, C., Nichol, S., Knipe, D. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> In Fields Virology. , 1741-1789 (2007).</li><li>Le May, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TFIIH+transcription+factor,+a+target+for+the+Rift+Valley+hemorrhagic+fever+virus.">TFIIH transcription factor, a target for the Rift Valley hemorrhagic fever virus.</a> Cell. 116, 541-550 (2004).</li><li>Caplen, H., Peters, C. J., Bishop, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutagen-directed+attenuation+of+Rift+Valley+fever+virus+as+a+method+for+vaccine+development.">Mutagen-directed attenuation of Rift Valley fever virus as a method for vaccine development.</a> J. Gen. Virol. 66, 2271-2277 (1985).</li><li>Ikegami, T., Won, S., Peters, C. J., Makino, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rescue+of+infectious+Rift+Valley+fever+virus+entirely+from+cDNA,+analysis+of+virus+lacking+the+NSs+gene,+and+expression+of+a+foreign+gene.">Rescue of infectious Rift Valley fever virus entirely from cDNA, analysis of virus lacking the NSs gene, and expression of a foreign gene.</a> J. Virol. 80, 2933-2940 (2006).</li><li>Vyboh, K., Ajamian, L., Mouland, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+viral+RNA+by+fluorescence+in+situ+hybridization+(FISH).">Detection of viral RNA by fluorescence in situ hybridization (FISH).</a> J. Vis. Exp. , e4002 (2012).</li><li>Reich, E., Goldberg, 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=Actinomycin+and+nucleic+acid+function.">Actinomycin and nucleic acid function.</a> Prog. Nucleic Acid Res. Mol. Biol. 3, 183-234 (1964).</li><li>Holmes, K. L., Lantz, L. M., Russ, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conjugation+of+fluorochromes+to+monoclonal+antibodies.">Conjugation of fluorochromes to monoclonal antibodies.</a> Curr. Protoc. Cytom. Chapter 4 (Unit 4 2), (2001).</li></ol>

利害の衝突は宣言されていない。

提供されたプロトコールは、新生RNAへウリジンアナログEUの取り込みを介して宿主細胞の転写に対するウイルス感染の影響を測定するための方法が記載されている。それは、高速で敏感であり、それは、放射性同位元素の使用に依存しない：この方法は、従来の方法に比べていくつかの利点を有する。さらに、この方法は、蛍光顕微鏡又は本質的に同じ試薬を用いてフローサイトメトリーを?...

<html>伝統的に、転写活性は、放射性（3 H-ウリジン）1のいずれかの取り込みを介して測定または新生RNAに（BRU）2ヌクレオシドハロゲン化されています。これらウリジン類似体は、細胞に取り込まヌクレオシドサルベージ経路を介しウリジン三リン酸（UTP）に変換され、続いて新たに合成されたRNAに組み込ま。3 H-ウリジンは、時間がかかることがオートラジオグラフィー、またはシンチレーションによって検出することができているカウント、特殊な装置を必要とします。さらに、放射性同位元素の使用が高い封じ込めバイオ研究所を含め、実験室の設定の数には実用的ではないかもしれない。 BRUは、RNA二次構造は、抗体結合のための立体障害かもしれないとして、RNAの核または部分変性に対する抗体のアクセスを確保するため厳しい透過処理が必要になる場合があります抗BRU抗体による免疫染色で検出することができます。 _content &quot;&gt;ここで記述されたプロトコルは、最近RVFV株MP-12に感染した細胞内で転写活性を測定する化学3をクリックして開発した。クリックケミストリーは非常に選択的かつ効率的な銅（I）触媒によるアルキンとの間の付加環化反応に依存して利用4,5アジド部分は、このプロトコルでは、感染細胞における新生RNAは、第ウリジンアナログEUの取り込みを介して標識される。第二 ​​工程では、取り込まれたEU、蛍光アジドとの反応により検出される。この方法の主な利点はそれは放射性同位元素の使用を必要とせず、それはRNAの過酷な透過又は変性を必要としないこと。50μm未満Daの分子量と（2）、蛍光アジドのアクセスが不十分なことによって妨げられない（1）ということである透過またはRNAの二次構造。クラスにRNAの検出を組み合わせた場合また、研究者は一次抗体の彼らの選択に限定されるものではないウイルスタンパク質の免疫染色のiCal。 蛍光顕微鏡（ステップ1-4）を介して転写を可視化するための一つであり、フローサイトメトリー（ステップ5-8）を介して転写を定量化するためのいずれかの2つの異なる方法は、このプロトコルに記載されている。どちらの方法でも、セル単位で転写活性とウイルス感染との間の相関を可能にするウイルスタンパク質に対する免疫細胞内で新生RNAの標識を結合する。 著者らは、正常プロトコルがRVFV株MP-12 6、トスカーナウイルス（TOSV）10に感染した別のMP-12変異体7,8、9、及び細胞に感染した細胞に感染した細胞において転写活性を決定するために、ここで説明に使用した。ここで説明するプロトコルは、簡単に異なるウイルスの使用に適合し、特定のウイルス又は細胞タンパク質の免疫蛍光染色を含むように修正される可能性を有することができる。

<table border="1">
	<tbody>
		<tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>5-ethynyl-uridine</td>
			<td>Berry &amp; Associates</td>
			<td>PY 7563</td>
			<td>dissolve in DMSO for 100 mM stock</td>
		</tr>
		<tr>
			<td>12-mm round coverslips</td>
			<td>Fisherbrand</td>
			<td>12-545-82</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>5 ml polystyrene tubes</td>
			<td>BD Biosciences</td>
			<td>352058</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Actinomycin D (ActD)</td>
			<td>Sigma</td>
			<td>9415</td>
			<td>dissolve in DMSO for 10 mM stock</td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 goat anti-mouse IgG</td>
			<td>Invitrogen</td>
			<td>A-11029</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>Santa Cruz</td>
			<td>sc-2323</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>CuSO4</td>
			<td>Sigma</td>
			<td>C-8027</td>
			<td>dissolve in H2O for 100 mM stock</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Sigma</td>
			<td>D-9542</td>
			<td>dissolve in H2O for 5 mg/ml stock</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Invitrogen</td>
			<td>11965092</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Invitrogen</td>
			<td>16000044</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>fluorescent azide (Alexa Fluor 594-coupled)</td>
			<td>Invitrogen</td>
			<td>A10270</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>fluorescent azide (Alexa Fluor 657-coupled)</td>
			<td>Invitrogen</td>
			<td>A10277</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Fluoromount-G</td>
			<td>Southern Biotech</td>
			<td>0100-01</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>L-ascorbic acid</td>
			<td>Sigma</td>
			<td>A-5960</td>
			<td>dissolve in H2O for 500 mM</td>
		</tr>
		<tr>
			<td>paper filter</td>
			<td>VWRbrand</td>
			<td>28333-087</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>paraformaldehyde</td>
			<td>Sigma</td>
			<td>158127</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>Invitrogen</td>
			<td>15140122</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>poly-L-lysine (MW &ge; 70000)</td>
			<td>Sigma</td>
			<td>P1274</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma</td>
			<td>T-8787</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Trizma base</td>
			<td>Sigma</td>
			<td>T-1503</td>
			<td>dissolve in H2O for 1.5 M stock, pH 8.5</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Invitrogen</td>
			<td>25200056</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Fluorescence Microscope</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>e.g. Olympus IX71</td>
		</tr>
		<tr>
			<td>Flow Cytometer</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>e.g. BD Biosciences LSRII Fortessa</td>
		</tr>
	</tbody>
</table>

using click chemistry to measure the effect of viral infection on host-cell rna synthesis

多くのRNAウイルスは、細胞の防御を回避する手段として、宿主細胞の転写を阻害する能力を進化させてきた。これらのウイルスの研究のために、感染細胞において転写活性を測定する迅速かつ信頼できる方法を有することが重要である。伝統的に、転写はH-ウリジンは、このような免疫を介して検出が続き、5 -ブロモウリジン（BRU）などのハロゲン化ウリジン類似体のオートラジオグラフィーまたはシンチレーション計数、または組み込みを介した検出が続く3などの放射性ヌクレオシドの取り込みのいずれかにより測定された。 BRUの検出が煩雑になることができ、低感度に苦しむかもしれない放射性同位体の使用は、しかしながら、特殊な装置を必要とし、実験室の設定の数には不可能である。 アジドとアルキンから銅触媒トリアゾール形成を含む最近開発されたクリックケミストリーは、今では迅速かつhighlを提供していますこれら2つの方法にyを敏感代わる。クリックケミストリーは、新生RNAは、第1の蛍光アジドとの標識の検出に続いてアナログウリジン-5 - ethynyluridine（EU）の取り込みにより標識された2段階プロセスである。これらのアジドは可視化のためのオプションの広い範囲を可能にする、いくつかの異なる蛍光体として利用可能です。 このプロトコルは、クリックケミストリーを用いたリフトバレー熱ウイルス（RVFV）株MP-12に感染した細胞内で転写抑制を測定する方法を説明しています。同時に、これらの細胞におけるウイルスタンパク質の発現は、古典的な細胞内の免疫染色によって決定される。 4詳細手順1〜8詳細を通して、フローサイトメトリーを介した転写抑制を定量化する方法を、手順5ながら、蛍光顕微鏡を介した転写抑制を可視化する方法。このプロトコルは、他のウイルスとの使用に容易に適応可能である。

P62のプロテアソームによる分解を促進することにより隔離することでは、（i）基本転写因子TFIIH 11と、（ii）のP44サブユニット：RVFVのNSsのタンパク質は、（ ブニヤウイルス科 、属フレボ ）11は、2つの異なるメカニズムを通じて宿主細胞一般的な転写を阻害TFIIH 6のサブユニット。 MP-12株は、生物学的安全性レベル2実験室で処理することができ、他の野?...

Watch this Scientific Journal Video about Using Click Chemistry to Measure the Effect of Viral Infection on Host-Cell RNA Synthesis at JoVE.com

Using Click Chemistry to Measure the Effect of Viral Infection on Host-Cell RNA Synthesis

この方法は、リフトバレー熱ウイルス（RVFV）MP-12株による感染の後、宿主細胞転写の変化を測定するためにクリックケミストリーの使用を記載している。結果は、蛍光顕微鏡を介して、定性的に可視化またはフローサイトメトリーを介して定量的に得ることができる。この方法は、他のウイルスとの使用に適合可能である。

宿主細胞のRNA合成でウイルス感染の効果を測定するためにクリックケミストリーを用いた

Many RNA viruses have evolved the ability to inhibit host cell transcription as a means to circumvent cellular defenses. For the study of these viruses, ...

using-click-chemistry-to-measure-effect-viral-infection-on-host-cell

Research

JoVE Journal

Immunology and Infection

11.6K ビュー.  University of Texas Medical Branch. この方法は、リフトバレー熱ウイルス（RVFV）MP-12株による感染の後、宿主細胞転写の変化を測定するためにクリックケミストリーの使用を記載している。結果は、蛍光顕微鏡を介して、定性的に可視化またはフローサイトメトリーを介して定量的に得ることができる。この方法は、他のウイルスとの使用に適合可能である。

ビデオ: Using Click Chemistry to Measure the Effect of Viral Infection on Host-Cell RNA Synthesis

Using a Pan-Viral Microarray Assay (Virochip) to Screen Clinical Samples for Viral Pathogens

The diagnosis of viral causes of many infectious diseases is difficult due to the inherent sequence diversity of viruses as well as the ongoing emergence of novel viral pathogens, such as SARS coronavirus and 2009 pandemic H1N1 influenza virus, that are not detectable by traditional methods. To address these challenges, we have previously developed and validated a pan-viral microarray platform called the Virochip with the capacity to detect all known viruses as well as novel variants on the basis of conserved sequence homology1. Using the Virochip, we have identified the full spectrum of viruses associated with respiratory infections, including cases of unexplained critical illness in hospitalized patients, with a sensitivity equivalent to or superior to conventional clinical testing2-5. The Virochip has also been used to identify novel viruses, including the SARS coronavirus6,7, a novel rhinovirus clade5, XMRV (a retrovirus linked to prostate cancer)8, avian bornavirus (the cause of a wasting disease in parrots)9, and a novel cardiovirus in children with respiratory and diarrheal illness10. The current version of the Virochip has been ported to an Agilent microarray platform and consists of ~36,000 probes derived from over ~1,500 viruses in GenBank as of December of 2009. Here we demonstrate the steps involved in processing a Virochip assay from start to finish (~24 hour turnaround time), including sample nucleic acid extraction, PCR amplification using random primers, fluorescent dye incorporation, and microarray hybridization, scanning, and analysis.

Using a Pan-Viral Microarray Assay Virochip to Screen Clinical Samples for Viral Pathogens

The Virochip is a pan-viral microarray designed to simultaneously detect all known viruses as well as novel viruses on the basis of conserved sequence homology. Here we demonstrate how to run a Virochip assay to analyze clinical samples for the presence of both known and unknown viruses.

ウイルス性病原体のために臨床サンプルをスクリーニングするためにパンウイルスマイクロアレイアッセイ（Virochip）を使用して、

The diagnosis of viral causes of many infectious diseases is difficult due to the inherent sequence diversity of viruses as well as the ongoing emergence ...

免疫・感染学

Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency

RNA viruses use RNA dependent RNA polymerases to replicate their genomes. The intrinsically high error rate of these enzymes is a large contributor to the generation of extreme population diversity that facilitates virus adaptation and evolution. Increasing evidence shows that the intrinsic error rates, and the resulting mutation frequencies, of RNA viruses can be modulated by subtle amino acid changes to the viral polymerase. Although biochemical assays exist for some viral RNA polymerases that permit quantitative measure of incorporation fidelity, here we describe a simple method of measuring mutation frequencies of RNA viruses that has proven to be as accurate as biochemical approaches in identifying fidelity altering mutations. The approach uses conventional virological and sequencing techniques that can be performed in most biology laboratories. Based on our experience with a number of different viruses, we have identified the key steps that must be optimized to increase the likelihood of isolating fidelity variants and generating data of statistical significance. The isolation and characterization of fidelity altering mutations can provide new insights into polymerase structure and function1-3. Furthermore, these fidelity variants can be useful tools in characterizing mechanisms of virus adaptation and evolution4-7.

The present article describes the steps required to isolate and characterize RNA polymerase fidelity variants of RNA viruses and how to use mutation frequency data to confirm fidelity changes in tissue culture.

ウイルスの変異頻度のRNAウイルスと特性の忠実性の変異の分離

RNA viruses use RNA dependent RNA polymerases to replicate their genomes. The intrinsically high error rate of these enzymes is a large contributor to the ...

Separation of Single-stranded DNA, Double-stranded DNA and RNA from an Environmental Viral Community Using Hydroxyapatite Chromatography

Viruses, particularly bacteriophages (phages), are the most numerous biological entities on Earth1,2. Viruses modulate host cell abundance and diversity, contribute to the cycling of nutrients, alter host cell phenotype, and influence the evolution of both host cell and viral communities through the lateral transfer of genes 3. Numerous studies have highlighted the staggering genetic diversity of viruses and their functional potential in a variety of natural environments. 
Metagenomic techniques have been used to study the taxonomic diversity and functional potential of complex viral assemblages whose members contain single-stranded DNA (ssDNA), double-stranded DNA (dsDNA) and RNA genotypes 4-9. Current library construction protocols used to study environmental DNA-containing or RNA-containing viruses require an initial nuclease treatment in order to remove nontargeted templates 10. However, a comprehensive understanding of the collective gene complement of the virus community and virus diversity requires knowledge of all members regardless of genome composition. Fractionation of purified nucleic acid subtypes provides an effective mechanism by which to study viral assemblages without sacrificing a subset of the community&#x2019;s genetic signature. 
Hydroxyapatite, a crystalline form of calcium phosphate, has been employed in the separation of nucleic acids, as well as proteins and microbes, since the 1960s11. By exploiting the charge interaction between the positively-charged Ca2+ ions of the hydroxyapatite and the negatively charged phosphate backbone of the nucleic acid subtypes, it is possible to preferentially elute each nucleic acid subtype independent of the others. We recently employed this strategy to independently fractionate the genomes of ssDNA, dsDNA and RNA-containing viruses in preparation of DNA sequencing 12. Here, we present a method for the fractionation and recovery of ssDNA, dsDNA and RNA viral nucleic acids from mixed viral assemblages using hydroxyapatite chromotography.

We describe an efficient method to separate single-stranded DNA, double-stranded DNA and RNA molecules from environmental viral communities. Nucleic acids are fractionated using hydroxyapatite chromatography with increasing concentrations of phosphate-containing buffers. This method permits the isolation of all viral nucleic acid types from environmental samples.

ハイドロキシアパタイトクロマトグラフィーを用いた環境ウイルスのコミュニティから一本鎖DNA、二本鎖DNAとRNAの分離

Viruses, particularly bacteriophages (phages), are the most numerous biological entities on Earth1,2.  Viruses modulate host cell abundance and diversity, ...

Chemoselective Modification of Viral Surfaces via Bioorthogonal Click Chemistry

The modification of virus particles has received a significant amount of attention for its tremendous potential for impacting gene therapy, oncolytic applications and vaccine development.1,2,3 Current approaches to modifying viral surfaces, which are mostly genetics-based, often suffer from attenuation of virus production, infectivity and cellular transduction.4,5 Using chemoselective click chemistry, we have developed a straightforward alternative approach which sidesteps these issues while remaining both highly flexible and accessible.1,2
The goal of this protocol is to demonstrate the effectiveness of using bioorthogonal click chemistry to modify the surface of adenovirus type 5 particles. This two-step process can be used both therapeutically1 or analytically,2,6 as it allows for chemoselective ligation of targeting molecules, dyes or other molecules of interest onto proteins pre-labeled with azide tags. The three major advantages of this method are that (1) metabolic labeling demonstrates little to no impact on viral fitness,1,7 (2) a wide array of effector ligands can be utilized, and (3) it is remarkably fast, reliable and easy to access.1,2,7
In the first step of this procedure, adenovirus particles are produced bearing either azidohomoalanine (Aha, a methionine surrogate) or the unnatural sugar O-linked N-azidoacetylglucosamine (O-GlcNAz), both of which contain the azide (-N3) functional group. After purification of the azide-modified virus particles, an alkyne probe containing the fluorescent TAMRA moiety is ligated in a chemoselective manner to the pre-labeled proteins or glycoproteins. Finally, an SDS-PAGE analysis is performed to demonstrate the successful ligation of the probe onto the viral capsid proteins. Aha incorporation is shown to label all viral capsid proteins (Hexon, Penton and Fiber), while O-GlcNAz incorporation results in labeling of Fiber only.
In this evolving field, multiple methods for azide-alkyne ligation have been successfully developed; however only the two we have found to be most convenient are demonstrated herein &#x2013; strain-promoted azide-alkyne cycloaddition (SPAAC) and copper-catalyzed azide-alkyne cycloaddition (CuAAC) under deoxygenated atmosphere.

Adenovirus particles are engineered to contain either the unnatural amino acid analogue azidohomoalanine or the azido sugar O-GlcNAz. The azide group of each is chemoselectively ligated via "click" chemistry reactions as a means of viral surface modification.

Bioorthogonalクリックケミストリーを介したウイルス表面の化学選択的修飾

The modification of virus particles has received a significant amount of attention for its tremendous potential for impacting gene therapy, oncolytic ...

The Synergistic Effect of Visible Light and Gentamycin on Pseudomona aeruginosa Microorganisms

Recently there were several publications on the bactericidal effect of visible light, most of them claiming that blue part of the spectrum (400 nm-500 nm) is responsible for killing various pathogens1-5. The phototoxic effect of blue light was suggested to be a result of light-induced reactive oxygen species (ROS) formation by endogenous bacterial photosensitizers which mostly absorb light in the blue region4,6,7. There are also reports of biocidal effect of red and near infra red8 as well as green light9.
In the present study, we developed a method that allowed us to characterize the effect of high power green (wavelength of 532 nm) continuous (CW) and pulsed Q-switched (Q-S) light on Pseudomonas aeruginosa. Using this method we also studied the effect of green light combined with antibiotic treatment (gentamycin) on the bacteria viability. P. aeruginosa is a common noscomial opportunistic pathogen causing various diseases. The strain is fairly resistant to various antibiotics and contains many predicted AcrB/Mex-type RND multidrug efflux systems10.
The method utilized free-living stationary phase Gram-negative bacteria (P. aeruginosa strain PAO1), grown in Luria Broth (LB) medium exposed to Q-switched and/or CW lasers with and without the addition of the antibiotic gentamycin. Cell viability was determined at different time points. The obtained results showed that laser treatment alone did not reduce cell viability compared to untreated control and that gentamycin treatment alone only resulted in a 0.5 log reduction in the viable count for P. aeruginosa. The combined laser and gentamycin treatment, however, resulted in a synergistic effect and the viability of P. aeruginosa was reduced by 8 log's.
The proposed method can further be implemented via the development of catheter like device capable of injecting an antibiotic solution into the infected organ while simultaneously illuminating the area with light.

The Synergistic Effect of Visible Light and Gentamycin on Pseudomona aeruginosa Microorganisms

We show that a developed biomedical device involving continuous or pulsed visible laser based treatment that is combined with antibiotic treatment (gentamycin), results in a statistically significant synergistic effect leading to a reduction in the viability of P. aeruginosa PAO1, by 8 log's compared to antibiotic treatment alone.

上の可視光およびゲンタマイシンの相乗効果<em&gt; Pseudomona緑膿菌</em&gt;微生物

Recently there were several publications on the  bactericidal effect of visible light, most of them claiming that blue part of  the spectrum (400 nm-500 ...

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

The apical and basolateral surfaces of airway epithelial cells demonstrate directional responses to pathogen exposure in vivo. Thus, ideal in vitro models for examining cellular responses to respiratory pathogens polarize, forming apical and basolateral surfaces. One such model is differentiated normal human bronchial epithelial cells (NHBE). However, this system requires lung tissue samples, expertise isolating and culturing epithelial cells from tissue, and time to generate an air-liquid interface culture.
Calu-3 cells, derived from a human bronchial adenocarcinoma, are an alternative model for examining the response of proximal airway epithelial cells to respiratory insult1, pharmacological compounds2-6, and bacterial7-9 and viral pathogens, including influenza virus, rhinovirus and severe acute respiratory syndrome - associated coronavirus10-14. Recently, we demonstrated that Calu-3 cells are susceptible to respiratory syncytial virus (RSV) infection in a manner consistent with NHBE15,16 . Here, we detail the establishment of a polarized, liquid-covered culture (LCC) of Calu-3 cells, focusing on the technical details of growing and culturing Calu-3 cells, maintaining cells that have been cultured into LCC, and we present the method for performing respiratory virus infection of polarized Calu-3 cells.
To consistently obtain polarized Calu-3 LCC, Calu-3 cells must be carefully subcultured before culturing in Transwell inserts. Calu-3 monolayer cultures should remain below 90% confluence, should be subcultured fewer than 10 times from frozen stock, and should regularly be supplied with fresh medium. Once cultured in Transwells, Calu-3 LCC must be handled with care. Irregular media changes and mechanical or physical disruption of the cell layers or plates negatively impact polarization for several hours or days. Polarization is monitored by evaluating trans-epithelial electrical resistance (TEER) and is verified by evaluating the passive equilibration of sodium fluorescein between the apical and basolateral compartments17,18 . Once TEER plateaus at or above 1,000 &Omega;&times;cm2, Calu-3 LCC are ready to use to examine cellular responses to respiratory pathogens.

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.

呼吸器病原体に対する宿主細胞応答を研究するために偏ヒト気道上皮Calu-3細胞の液体に覆われた文化の確立<em&gt;インビトロ</em

The  apical and basolateral surfaces of airway epithelial cells demonstrate  directional responses to pathogen exposure in  vivo. Thus, ideal in vitro ...

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins

Streptococcus pneumoniae colonizes the highly diverse polymicrobial community of the nasopharynx where it must compete with resident organisms. We have shown that bacterially produced antimicrobial peptides (bacteriocins) dictate the outcome of these competitive interactions. All fully-sequenced pneumococcal strains harbor a bacteriocin-like peptide (blp) locus. The blp locus encodes for a range of diverse bacteriocins and all of the highly conserved components needed for their regulation, processing, and secretion. The diversity of the bacteriocins found in the bacteriocin immunity region (BIR) of the locus is a major contributor of pneumococcal competition. Along with the bacteriocins, immunity genes are found in the BIR and are needed to protect the producer cell from the effects of its own bacteriocin. The overlay assay is a quick method for examining a large number of strains for competitive interactions mediated by bacteriocins. The overlay assay also allows for the characterization of bacteriocin-specific immunity, and detection of secreted quorum sensing peptides. The assay is performed by pre-inoculating an agar plate with a strain to be tested for bacteriocin production followed by application of a soft agar overlay containing a strain to be tested for bacteriocin sensitivity. A zone of clearance surrounding the stab indicates that the overlay strain is sensitive to the bacteriocins produced by the pre-inoculated strain. If no zone of clearance is observed, either the overlay strain is immune to the bacteriocins being produced or the pre-inoculated strain does not produce bacteriocins. To determine if the blp locus is functional in a given strain, the overlay assay can be adapted to evaluate for peptide pheromone secretion by the pre-inoculated strain. In this case, a series of four lacZ-reporter strains with different pheromone specificity are used in the overlay.

Competition in Streptococcus pneumoniae is mediated by bacteriocins, small antimicrobial peptides with inhibitory activity towards pneumococcus and other related species.&#160; Here we describe an optimized bacterial overlay assay that allows for the characterization of bacteriocin activity and inhibitory spectrum, bacteriocin-specific immunity, and detection of secreted quorum sensing peptides.

定性的にオーバーレイアッセイを使用すると、肺炎球菌バクテリオシンに対する細菌の産生と感度を測定します

Streptococcus pneumoniae colonizes the highly diverse polymicrobial community of the nasopharynx where it must compete with resident organisms.  We have ...

Nucleocapsid Annealing-Mediated Electrophoresis (NAME) Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors

RNA or DNA folded in stable tridimensional folding are interesting targets in the development of antitumor or antiviral drugs. In the case of HIV-1, viral proteins involved in the regulation of the virus activity recognize several nucleic acids. The nucleocapsid protein NCp7 (NC) is a key protein regulating several processes during virus replication. NC is in fact a chaperone destabilizing the secondary structures of RNA and DNA and facilitating their annealing. The inactivation of NC is a new approach and an interesting target for anti-HIV therapy. The Nucleocapsid Annealing-Mediated Electrophoresis (NAME) assay was developed to identify molecules able to inhibit the melting and annealing of RNA and DNA folded in thermodynamically stable tridimensional conformations, such as hairpin structures of TAR and cTAR elements of HIV, by the nucleocapsid protein of HIV-1. The new assay employs either the recombinant or the synthetic protein, and oligonucleotides without the need of their previous labeling. The analysis of the results is achieved by standard polyacrylamide gel electrophoresis (PAGE) followed by conventional nucleic acid staining. The protocol reported in this work describes how to perform the NAME assay with the full-length protein or its truncated version lacking the basic N-terminal domain, both competent as nucleic acids chaperones, and how to assess the inhibition of NC chaperone activity by a threading intercalator. Moreover, NAME can be performed in two different modes, useful to obtain indications on the putative mechanism of action of the identified NC inhibitors.

Nucleocapsid Annealing-Mediated Electrophoresis NAME Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors

This protocol describes NAME, an assay that allows the rapid identification of molecules able to inhibit in vitro the chaperone activities of HIV-1 nucleocapsid protein.

ヌクレオカプシドアニーリング媒介電気泳動（NAME）アッセイは、HIV-1ヌクレオカプシド阻害剤の迅速な同定を可能にする

RNA or DNA folded in stable tridimensional folding are interesting targets in the development of antitumor or antiviral drugs. In the case of HIV-1, viral ...

The Development of Lyophilized Loop-mediated Isothermal Amplification Reagents for the Detection of Coxiella burnetii

Coxiella burnetii, the agent causing Q fever, is an obligate intracellular bacterium. PCR based diagnostic assays have been developed for detecting C. burnetii DNA in cell cultures and clinical samples. PCR requires specialized equipment and extensive end user training, and therefore, it is not suitable for routine work especially in a resource-constrained area. We have developed a loop-mediated isothermal amplification (LAMP) assay to detect the presence of C. burnetii in patient samples. This method is performed at a single temperature around 60 &#176;C in a water bath or heating block. The sensitivity of this LAMP assay is very similar to PCR with a detection limit of about 25 copies per reaction. This report describes the preparation of the reaction using lyophilized reagents and visualization of results using hydroxynaphthol blue (HNB) or a UV lamp with fluorescent intercalating dye in the reaction. The LAMP reagents were lyophilized and stored at room temperature (RT) for one month without loss of detection sensitivity. This LAMP assay is particularly robust because the reaction mixture preparation does not involve complex steps. This method is ideal for use in resource-limited settings where Q fever is endemic.

The Development of Lyophilized Loop-mediated Isothermal Amplification Reagents for the Detection of Coxiella burnetii

We described here a simple loop-mediated isothermal amplification (LAMP) method using lyophilized reagents for the detection of C. burnetii in patient samples.

の検出のための凍結乾燥LAMP法試薬の開発<em&gt; Q熱リケッチア</em

Coxiella burnetii, the agent causing Q fever, is an obligate intracellular bacterium. PCR based diagnostic assays have been developed for detecting C. ...

Swab Sampling Method for the Detection of Human Norovirus on Surfaces

Human noroviruses are a leading cause of epidemic and sporadic gastroenteritis worldwide. Because most infections are either spread directly via the person-to-person route or indirectly through environmental surfaces or food, contaminated fomites and inanimate surfaces are important vehicles for the spread of the virus during norovirus outbreaks.
We developed and evaluated a protocol using macrofoam swabs for the detection and typing of human noroviruses from hard surfaces. Compared with fiber-tipped swabs or antistatic wipes, macrofoam swabs allow virus recovery (range 1.2-33.6%) from toilet seat surfaces of up to 700 cm2. The protocol includes steps for the extraction of the virus from the swabs and further concentration of the viral RNA using spin columns. In total, 127 (58.5%) of 217 swab samples that had been collected from surfaces in cruise ships and long-term care facilities where norovirus gastroenteritis had been reported tested positive for GII norovirus by RT-qPCR. Of these 29 (22.8%) could be successfully genotyped. In conclusion, detection of norovirus on environmental surfaces using the protocol we developed may assist in determining the level of environmental contamination during outbreaks as well as detection of virus when clinical samples are not available; it may also facilitate monitoring of effectiveness of remediation strategies.

A macrofoam based sampling methodology was developed and evaluated for the detection and quantification of norovirus on environmental hard surfaces.

表面上のヒトノロウイルスの検出のためのスワブサンプリング方法

Human noroviruses are a leading cause of epidemic and sporadic gastroenteritis worldwide. Because most infections are either spread directly via the ...