この作業に対する財政的支援は、欧州共同体(ERC-STG INTRACELLTBグラントn°260901、MM4TBグラントn°260872)、アジェンス・ナショナル・ド・レシェルシュ、フェダー(12001407(D-AL)エクイペックス・イマジックス・バイオメッド)、および地域ノルド・パ・ド・カレーによって提供されました。私たちは、プラットフォームBICeLからガスパール・デロイソン、エリザベス・ヴェルクマイスター、アントニーノ・ボンジョヴァンニ、フランク・ラフォントの技術支援を感謝しています。

1. ハイスループットゲノムワイドsiRNAスクリーニング
緑色蛍光タンパク質(GFP)を発現するMtb H37Rvに感染したヒトII型気球モデルA549細胞系でスクリーニングを行う。この手順の概要は 、図 1Aに示します。
<ol><li>1x siRNAバッファーで保存されている乾燥したsiRNAライブラリ(96ウェルプレート)を4μMの濃度に達し、その混合物の10μlを384ウェルの娘プレート(ドータープレート1)に移します。</li>
	<li>10 μlの1x siRNAバッファーを娘プレート1に加え、siRNAを2倍希釈します。siRNA再懸濁後、プレートは剥離可能なアルミニウムシールで密封され、少なくとも6ヶ月および2〜3年まで-20°Cで保存することができますが、貯蔵時間はsiRNAライブラリメーカーの推奨によって異なる場合があります。</li>
	<li>娘プレート1のsiRNAを娘プレート2に希釈し、500nMの濃度に達した。siRNA再懸濁後、プレートは剥離可能なアルミニウムシールで密封され、少なくとも6ヶ月および2〜3年まで-20°Cで保存することができますが、貯蔵時間はsiRNAライブラリメーカーの推奨によって異なる場合があります。</li>
	<li>使用前に、室温で娘プレート2を解凍する。</li>
	<li>2.5 μlのsiRNAを娘プレート2から取り出し、384ウェルアッセイプレートに入れる。</li>
	<li>ステップ1.5の同じ384ウェルアッセイプレートで、2.5 μlの陰性および正のコントロールsiRNAをそれぞれのウェルに加えます。</li>
	<li>トランスフェクション試薬を1x D-PBSで希釈して、各ウェルに0.1μlトランスフェクション試薬を提供するのに十分な溶液を得て、希釈トランスフェクション溶液を室温で5分間前キューバ化します。</li>
	<li>トランスフェクション試薬/PBS溶液混合物をアッセイプレートの各ウェルに7.5 μl添加し、室温で30分間インキュベートします。</li>
	<li>10%のウシ胎児血清(FBS)を添加したRPMI 1640培地に懸濁したA549細胞(1,500細胞/ウェル)の40 μlを加えます。5%CO2を含む雰囲気中で37°Cで3日間培養期間の細胞を維持する。これらの細胞は24時間ごとに分裂し、したがって約12,000個の細胞がトランスフェクションの3日後にウェル内にある。</li>
	<li>2週間前のGFP発現 Mtb H37Rv培養物をD-PBS(MgCl2 およびCaCl2から無料)で4,000 x gで5分間遠心して洗浄を廃棄します。このステップを 3x. 繰り返します(GFP-Mtb H37Rv カルチャ条件の場合はプロトコル 3 を参照してください)。</li>
	<li>10%FBSを添加したRPMI 1640培地の10mlで細菌ペレットを懸濁し、室温で1時間デカントして、細菌凝集体を堆積物にできるようにします。</li>
	<li>細菌の上清を収集し、測定OD600(OD 600 は0.6-0.8の間でなければならない)とGFP-蛍光(RFU値)をマイクロプレートリーダーを使用して細菌の濃度を決定します。同じ条件で調製された別の培養物に対して実験前に生成されたRFU値=f(CFU値)を表示する参照回帰線を用いて懸濁液の力価を算出する。感染の多重度(MOI)5に対応する2.4 x 106 個の細菌/mlを含む細菌懸濁液を調製します。</li>
	<li>384ウェルアッセイプレート内の培地を取り出し、25μlの新たに調製した細菌懸濁液を加えます。</li>
	<li>384ウェルアッセイプレートを5%CO2を含む雰囲気で5時間37°Cでインキュベートする。</li>
	<li>培地を取り出し、10%FBS 3xを添加したRPMI培地で細胞を静かに洗います。</li>
	<li>残りの細胞外細菌を殺すために、5%CO2を含む大気中で、50μg/mlのアミカシンを含む50μlの新鮮なRPMI-FBS培地を37°Cで1時間処理する。</li>
	<li>培地含有アミカシンを取り出し、10%FBSを添加した新鮮なRPMI培地を50μl加えます。384ウェルアッセイプレートを5%CO2を含む雰囲気で5日間、37°Cでインキュベートする。</li>
	<li>画像取得前に、PBSで作りたての30μg/mlのDAPI(最終濃度5μg/ml)を10 μl加え、37°Cで10分間インキュベートします。</li>
	<li>プレートを自動共焦点顕微鏡に積み込みます。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_1highres.jpg" src="/files/ftp_upload/51114/screenshot_1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>露出パラメータを設定します。放出フィルター520 nmを用いた励起レーザー450nmおよびGFP蛍光を用いた励起レーザー405 nmを用いたDAPI蛍光を記録する。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_2-1highres.jpg" src="/files/ftp_upload/51114/screenshot_2-1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_2-1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a> <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_2-2highres.jpg" src="/files/ftp_upload/51114/screenshot_2-2.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_2-2highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>取得する各ウェルのウェルとフィールドを選択し、レイアウトパラメータとサブレイアウトパラメータと呼びます。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_3-1highres.jpg" src="/files/ftp_upload/51114/screenshot_3-1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_3-1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a> <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_3-2highres.jpg" src="/files/ftp_upload/51114/screenshot_3-2.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_3-2highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>手順 1.20 および 1.21 のパラメータを使用して実験ファイルを生成し、自動取得を実行します。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_4-1highres.jpg" src="/files/ftp_upload/51114/screenshot_4-1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_4-1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a> <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_4-2highres.jpg" src="/files/ftp_upload/51114/screenshot_4-2.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_4-2highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>リモート サーバーにイメージを転送します。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_5highres.jpg" src="/files/ftp_upload/51114/screenshot_5.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_5highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>画像解析ソフトウェアを使用して画像を評価します。ピクセル強度特性アルゴリズムを用いて、核検出アルゴリズムとGFPチャンネルからの細菌領域を用いてDAPIチャネルから細胞核を検出する(図4A)。</li>
</ol>注: このプロトコルは、細胞内 Mtb 成長に対する遺伝子サイレンシングの効果を調べるように最適化されています。 Mtb は、最適な条件で20時間ごとに分割する低成長細菌です。感染後5日後、細胞外 Mtb の量は、細胞内のリシスがない場合にはまだ少なく、分析の質に影響を与えなかった。このプロトコルは、広範囲に放出され、新しい細胞に感染することができる マイコバクテリアススメグマティスや大腸菌 のような急速成長細菌を使用してsiRNAスクリーンに適応する抗生物質治療およびインキュベーション時間の長さの点で最適化されなければならない。
2. ハイスループット複合スクリーニング
Mtb H37Rv感染宿主細胞に対してスクリーニングを行った。この手順の概要は 図 1Bで説明しています。
<ol><li>DMSO 100%で可溶化した化合物ライブラリーを含む384ウェルのマザープレートを解凍する。10%FBSを添加したRPMI 1640培地10μlを含む384ウェルのドータープレートに0.5 μlの化合物を移します。</li>
	<li>2週間前のGFP発現 Mtb H37Rv培養物をD-PBS(MgCl2 およびCaCl2から無料)で4,000 x gで5分間遠心して洗浄を廃棄します。このステップ 3x を繰り返します(GFP-Mtb H37Rv カルチャ条件の場合は、プロトコル 3 を参照してください)。</li>
	<li>10%FBSを添加したRPMI 1640培地の10mlで細菌ペレットを懸濁し、室温で1時間デカントして、細菌凝集体を堆積物にできるようにします。</li>
	<li>細菌の上清を収集し、マイクロプレートリーダーを使用してOD600(OD 600は0.6-0.8の間でなければならない)とGFP蛍光(RFU値)を測定します。実験前に生成されたRFU値=f(CFU値)を表示する参照回帰線を用いて懸濁液の力価を計算する。典型的な濃度は1 x 108の細菌/mlである。</li>
	<li>収穫 6 日古い初代ヒトマクロファージRPMI 1640 培地で 10% ウシ胎児血清 (FBS) および 50 ng/ml 組み換えヒト M-CSF (ヒト末梢血単球細胞の精製およびマクロファージ分化についてはプロトコル 4 参照) を補充した。</li>
	<li>希釈した一次細胞を異なるMOIで、1〜5の範囲で、37°Cで2時間90rpmで軽度の揺れを伴う懸濁液でインキュベートする。</li>
	<li>感染した細胞を350xgで遠心分離して洗浄し、細胞外細菌を除去する。各遠心分離工程の後、10%FBSを添加したRPMI 1640培地中のペレットを再懸濁する。この手順を 2x 繰り返します。</li>
	<li>10%FBSとアミカシンを50 μg/mlで補充したRPMI 1640培地中の感染細胞を一時停止し、37°Cで1時間の軽い揺れを伴う懸濁液をインキュベートする。</li>
	<li>アミカシンを含む培地を350xgで遠心分離して除去し、10%FBSおよび50ng/ml組み換えヒトM-CSFを添加した完全なRPMI 1640培地で感染細胞を洗浄する。1 回繰り返します。</li>
	<li>ステップ2.1の同じアッセイプレートに40μlの感染マクロファージ懸濁液を加え、すでに10μlの化合物希釈液を含んでいる。各ウェルのDMSOの最終濃度は1%に達しました。</li>
	<li>5%CO2を含む雰囲気の中で37°Cで5日間アッセイプレートをインキュベートする。</li>
	<li>細胞透過性の遠赤色蛍光色素で生細胞を染色する。</li>
	<li>プレートを自動共焦点顕微鏡に積み込みます。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_1highres.jpg" src="/files/ftp_upload/51114/screenshot_1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>露出パラメータを設定します。発光フィルター520 nmを用いた励起レーザー488nmを用いた発光フィルター690 nmおよびGFP蛍光を用いた励起レーザー640 nmを用いた極赤色蛍光を記録する。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_2-1highres.jpg" src="/files/ftp_upload/51114/screenshot_2-1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_2-1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a> <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_2-2highres.jpg" src="/files/ftp_upload/51114/screenshot_2-2.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_2-2highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>取得する各ウェルのウェルとフィールドを選択し、レイアウトパラメータとサブレイアウトパラメータと呼びます。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_3-1highres.jpg" src="/files/ftp_upload/51114/screenshot_3-1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_3-1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a> <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_3-2highres.jpg" src="/files/ftp_upload/51114/screenshot_3-2.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_3-2highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>手順 2.14 および 2.15 のパラメータを使用して実験ファイルを生成し、自動取得を実行します。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_4-1highres.jpg" src="/files/ftp_upload/51114/screenshot_4-1.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_4-1highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a> <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_4-2highres.jpg" src="/files/ftp_upload/51114/screenshot_4-2.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_4-2highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>リモート サーバーにイメージを転送します。 <img fo:content-width="5in" fo:src="/files/ftp_upload/51114/screenshot_5highres.jpg" src="/files/ftp_upload/51114/screenshot_5.jpg"> <a href="https://www.jove.com/files/ftp_upload/51114/screenshot_5highres.jpg" target="_blank">ここをクリックすると、より大きな画像が表示されます。</a></li>
	<li>画像解析ソフトウェアを使用して画像を評価します。ピクセル強度特性アルゴリズムを使用して、GFPチャンネルから、ピクセル強度特性アルゴリズムと細菌領域を用いて遠赤色チャネルから細胞領域を検出する(図4B)。</li>
</ol>注:このプロトコルは、蛍光タンパク質を発現する変異体(1つのウェル/ワン変異体)によって化合物を置換することによってMtb変異ライブラリースクリーニングに適応することができる(図1C、Brodinらも参照)。4)蛍光変異体は、まずウェル(ウェルあたり20μlの細菌懸濁液)に播種される。細菌は、その後、細胞懸濁液の30 μlによって回収されます。350xgで1分間遠心分離した後、プレートを5%CO2を含む雰囲気中で37°Cでインキュベートする。インキュベーション時間とMOIはアッセイに依存します。例として、ファゴソーム酸性化などの初期の細胞事象を可視化するために、細胞は1〜20の範囲のMOIで2時間感染することができる。リソソームは、5%CO2を含む雰囲気の中で37°Cで1.5時間2μMのリソトラッカー色素を使用して染色され、10%ホルマリンまたは4%パラホルムアルデヒド(PFA)で固定されます。共焦点画像は、リソソーム検出および細胞内局在化のための適切なアルゴリズムを特徴とする画像解析スクリプトを用いて取得し、最終的に解析される。
3. 緑色蛍光タンパク質結核菌H37Rv(GFP-H37Rv)の培養条件を発現
長期保存のために、GFP-H37RvはD-PBSで凍結した(バイアルあたり約1 x 108 マイコバクテリア)。
<ol><li>ミドルブルックOADC濃縮10%、グリセロール0.5%、Tween-80 0.05%、ハイグロマイシンB(50μg/ml)を添加した7H9スープ培地50mlを含むエルレンマイヤーフラスコ中のGFP-H37Rvの冷凍在庫バイアルを再懸濁します。</li>
	<li>37°Cで8日間インキュベートする。</li>
	<li>GFP-H37Rv培養のOD600 を測定する。</li>
	<li>GFP-H37Rv培養液を希釈して、ミドルブルックOADC濃縮10%、 グリセロール0.5%、Tween-80 0.05%、ハイグロマイシンB(50μg/ml)を添加した新鮮な7H9ブロス培地でOD 600=0.1を得る。</li>
	<li>GFP-H37Rvを37°Cで8日間インキュベートしてから、アッセイに使用してください。</li>
</ol>4. 全血またはバフィーコート調製からのヒト末梢血単球細胞精製
<ol><li>1%FBSを含む1x D-PBS(MgCl 2およびCaCl2から解放)で血液ポーチ2xを希釈します。</li>
	<li>400 x g で Ficoll 密度勾配遠心分離により 20 分間、単球を分離します。</li>
	<li>単球を収集します。</li>
	<li>1x D-PBS(MgCl2 およびCaCl2から自由)で1%FBSを含む1%FBSを室温で10分間400xgで遠心分離して、単球3xを洗浄します。</li>
	<li>細胞を1 x 107の細胞 /mlまで濃縮します。</li>
	<li>メーカーのプロトコルに従ってCD14磁気ビーズを使用して単球を精製します(材料を参照)。</li>
	<li>CD14-単球精製後、細胞を1.5 x 106細胞/ml RPMI 1640で播種し、10%FBSおよび40ng/mlのヒトマクロファージコロニー刺激因子(hM-CSF)を補い、5%CO2を含む雰囲気で37°Cで4日間インキュベートした。</li>
	<li>4日後、培地を新鮮なRPMI 1640で交換し、10%FBSと40ng/mlのhM-CSFで補い、5%CO2を含む雰囲気中で37°Cで2日間インキュベートした。</li>
	<li>6日後、細胞はアッセイに使用することができる。</li>
</ol>

<ol>
	<li>Gandhi, N. R., 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=Multidrug-resistant+and+extensively+drug-resistant+tuberculosis:+a+threat+to+global+control+of+tuberculosis.">Multidrug-resistant and extensively drug-resistant tuberculosis: a threat to global control of tuberculosis.</a> Lancet. 375, 1830-1843 (2010).</li><li>Barry, C. E., 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=The+spectrum+of+latent+tuberculosis:+rethinking+the+biology+and+intervention+strategies.">The spectrum of latent tuberculosis: rethinking the biology and intervention strategies.</a> Nat. Rev. Microbiol. 7, 845-855 (2009).</li><li>Christophe, T., Ewann, F., Jeon, H. K., Cechetto, J., Brodin, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-content+imaging+of+Mycobacterium+tuberculosis-infected+macrophages:+an+in+vitro+model+for+tuberculosis+drug+discovery.">High-content imaging of Mycobacterium tuberculosis-infected macrophages: an in vitro model for tuberculosis drug discovery.</a> Future Med. Chem. 2, 1283-1293 (2010).</li><li>Brodin, P., 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=High+content+phenotypic+cell-based+visual+screen+identifies+Mycobacterium+tuberculosis+acyltrehalose-containing+glycolipids+involved+in+phagosome+remodeling.">High content phenotypic cell-based visual screen identifies Mycobacterium tuberculosis acyltrehalose-containing glycolipids involved in phagosome remodeling.</a> PLoS Pathog. 6, (2010).</li><li>Bermudez, L. E., Goodman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mycobacterium+tuberculosis+invades+and+replicates+within+type+II+alveolar+cells.">Mycobacterium tuberculosis invades and replicates within type II alveolar cells.</a> Infect. Immun. 64, 1400-1406 (1996).</li><li>Dobos, K. M., Spotts, E. A., Quinn, F. D., King, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Necrosis+of+lung+epithelial+cells+during+infection+with+Mycobacterium+tuberculosis+is+preceded+by+cell+permeation.">Necrosis of lung epithelial cells during infection with Mycobacterium tuberculosis is preceded by cell permeation.</a> Infect. Immun. 68, 6300-6310 (2000).</li><li>McDonough, K. A., Kress, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytotoxicity+for+lung+epithelial+cells+is+a+virulence-associated+phenotype+of+Mycobacterium+tuberculosis.">Cytotoxicity for lung epithelial cells is a virulence-associated phenotype of Mycobacterium tuberculosis.</a> Infect. Immun. 63, 4802-4811 (1995).</li><li>Lee, H. M., Yuk, J. M., Shin, D. M., Jo, E. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dectin-1+is+inducible+and+plays+an+essential+role+for+mycobacteria-induced+innate+immune+responses+in+airway+epithelial+cells.">Dectin-1 is inducible and plays an essential role for mycobacteria-induced innate immune responses in airway epithelial cells.</a> J. Clin. Immunol. 29, 795-805 (2009).</li><li>Zhang, J. H., Chung, T. D., Oldenburg, K. 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P., 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=Automated+high-throughput+siRNA+transfection+in+raw+264.7+macrophages:+a+case+study+for+optimization+procedure.">Automated high-throughput siRNA transfection in raw 264.7 macrophages: a case study for optimization procedure.</a> J. Biomol. Screen. 14, 151-160 (2009).</li><li>Zhang, X. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Illustration+of+SSMD,+z+score,+SSMD*,+z*+score,+and+t+statistic+for+hit+selection+in+RNAi+high-throughput+screens.">Illustration of SSMD, z score, SSMD*, z* score, and t statistic for hit selection in RNAi high-throughput screens.</a> J. Biomol. Screen. 16, 775-785 (2011).</li><li>Song, O. 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利益相反は宣言されていません。

ここでは、蛍光標識された宿主細胞に感染するためにGFP発現 Mtb H37Rv株を用いた表現型アッセイに必要な方法を説明し、高含有量/ハイスループットスクリーンに適しています。このプロトコルは、広範囲の化合物、蛍光プローブおよび Mtb 変異体に適用することができる。上述した各プロトコルについて、画像取得前に固定および免疫標識のステップを行うことができた。20X(NA 0....

過去数年間に報告された新興および再興性感染病原体の中で、結核菌(Mtb)は、2011年に140万人の死亡と870万人の新しい感染症の原因となる著名な場所を保持しています(世界結核レポート2012、www.who.int/topics/tuberculosis/en/)。多剤療法の利用可能性にもかかわらず、感染者数は依然として増加しており、多剤耐性(MDR)ならびに広範囲に薬剤耐性(XDR)Mtbは急速に世界中に広がっている1。また、Mtb抗原の存在を考慮すると、全世界の人口の3分の1がMtbによって潜感染していると考えられることは明らかである。したがって、Mtbと戦う新しい手段が緊急に必要とされています。この文脈で、我々は、自動共焦点蛍光顕微鏡3によるMtbの浸潤および増殖を宿主細胞に監視することに頼るインビトロ視覚表現型アッセイを開発した。384ウェルマイクロタイタープレートでのアッセイの適応は、自動画像取得および分析と組み合わせて、化合物、siRNAおよび細菌変異体の中規模ライブラリーの高含有量/ハイスループットスクリーニング(HC/HTS)を可能にした。この表現型アッセイに関するゲノムワイドRNAiライブラリのスクリーニングにより、Mtb人身売買や細胞内複製に関与する主要な宿主因子の同定が可能になっただけでなく、結核菌によって悪用される宿主経路の解明も可能になった。この特定の表現形学アッセイのもう一つの適応は、Mtbの食前体内持続性に不可欠な細菌因子の同定であった。例えば、ファゴソーム成熟の逮捕は、マクロファージにおけるMtbの生存および複製を促進する主要なメカニズムの1つと考えられている。蛍光標識酸性コンパートメントにおけるMtbノックアウト変異体の細胞内局在のモニタリングにより、生存プロセス4に関与する細菌遺伝子の同定が可能となった。最後に、Mtbの高含有イメージングは、細胞内細菌増殖などの様々な現象を阻害するための薬剤効率を定量化する優れた方法も提供する3。全体として、このタイプの高スループット表現型アッセイは、結核に対する創薬を加速することを可能にし、これらの異なるアプローチによって収集されたデータは、Mtbによって行われるホスト操作のより良い理解に寄与する。

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	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">&#181;clear-plate black, 384 well</td>
			<td style="width:160px;">Greiner bio-one</td>
			<td style="width:175px;">781091</td>
			<td style="width:388px;">127.8/86/15 MM with Lid, TC treated</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">CellCarrier 384 well plate</td>
			<td style="width:160px;">PerkinElmer</td>
			<td style="width:175px;">6007550</td>
			<td>Black, Clear Bottom, with Lid, TC treated</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">V-bottom white , 384 well-plate</td>
			<td style="width:160px;">Greiner bio-one</td>
			<td style="width:175px;">781280</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">sealing tape, breathable, sterile</td>
			<td style="width:160px;">Corning</td>
			<td style="width:175px;">3345</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Lipofectamine RNAiMax</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">13778150</td>
			<td>Transfection reagent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Dimethyl sulfoxide</td>
			<td style="width:160px;">Sigma-Aldrich</td>
			<td style="width:175px;">34943</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">RPMI 1640 + GlutaMAX-I</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">61870-010</td>
			<td>Cell culture medium</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">D-PBS 1X [-]MgCl2/[-]CaCl2</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">14190-094</td>
			<td>Dulbecco&#39;s Phosphate Salin Buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">D-PBS 1X [+]MgCl2/[+]CaCl2</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">14190-091</td>
			<td>Dulbecco&#39;s Phosphate Salin Buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Fetal bovine serum</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">2610040-79</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">FICOLL PAQUE PLUS</td>
			<td style="width:160px;">DUTSCHER</td>
			<td style="width:175px;">17-1440-03</td>
			<td>Ficoll for Peripherical Blood Monocyte Cells purification</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">CD14 MicroBeads, human</td>
			<td style="width:160px;">Miltenyi</td>
			<td style="width:175px;">130-050-201</td>
			<td>Purification of CD14+ Monocytes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Human M-CSF, premium gr. (1000 &#956;g)</td>
			<td style="width:160px;">Miltenyi</td>
			<td style="width:175px;">130-096-493</td>
			<td>Macrophage Colony Stimulating Factor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">LS Columns</td>
			<td style="width:160px;">Miltenyi</td>
			<td style="width:175px;">130-042-401</td>
			<td>Columns for CD14+ Monocytes isolation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Tween 80</td>
			<td style="width:160px;">Euromedex</td>
			<td style="width:175px;">2002-A</td>
			<td>Mycobacteria culture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Glycerol high purity </td>
			<td style="width:160px;">Euromedex</td>
			<td style="width:175px;">50405-EX</td>
			<td>Mycobacteria culture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;"> Middlebrook OADC enrichment</td>
			<td style="width:160px;">Becton-Dickinson</td>
			<td style="width:175px;">211886</td>
			<td>Mycobacteria culture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">7H9</td>
			<td style="width:160px;">Becton-Dickinson</td>
			<td style="width:175px;">W1701P</td>
			<td>Mycobacteria culture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Versene 1X</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">15040033</td>
			<td>Non enzymatic cell dissociation solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">DAPI</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">D1306</td>
			<td>Nuclei dye</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Hoechst 33342</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">H3570</td>
			<td>Nuclei dye</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Syto60</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">S11342</td>
			<td>Nuclei/cytoplasm dye</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Formalin</td>
			<td style="width:160px;">Sigma-Aldrich</td>
			<td style="width:175px;">HT5014</td>
			<td>Cell fixation solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">siRNA targeting Dectin-1</td>
			<td style="width:160px;">Santa-Cruz</td>
			<td style="width:175px;">sc-63276</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">*siGenome* Non targeted siRNA pool </td>
			<td style="width:160px;">Dharmacon</td>
			<td style="width:175px;">D-001206-14</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Rifampicin</td>
			<td style="width:160px;">Sigma-Aldrich</td>
			<td style="width:175px;">R3501</td>
			<td>antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Isoniazid (INH)</td>
			<td style="width:160px;">Sigma-Aldrich</td>
			<td style="width:175px;">I3377-50G</td>
			<td>antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Hygromycin B</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:175px;">10687-010</td>
			<td>antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Amikacin</td>
			<td style="width:160px;">Sigma-Aldrich</td>
			<td style="width:175px;">A1774</td>
			<td>antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Automated Confocal Microscope OPERA</td>
			<td style="width:160px;">PerkinElmer</td>
			<td style="width:175px;"> </td>
			<td>Image acquisition</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Columbus 2.3.1 Server Database</td>
			<td style="width:160px;">PerkinElmer</td>
			<td style="width:175px;"> </td>
			<td>Data transfert, storage and analysis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Acapella 2.6 software</td>
			<td style="width:160px;">PerkinElmer</td>
			<td style="width:175px;"> </td>
			<td>Image-based analysis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">GraphPad Prism5 software</td>
			<td style="width:160px;">GraphPad </td>
			<td style="width:175px;"> </td>
			<td>Statistical analysis</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:287px;">Excel 2010</td>
			<td style="width:160px;">Microsoft</td>
			<td style="width:175px;"> </td>
			<td>Statistical analysis</td>
		</tr>
	</tbody>
</table>

a microscopic phenotypic assay for the quantification of intracellular mycobacteria adapted for high-throughput/high-content screening

治療とワクチンが利用できるにもかかわらず、結核(TB)は世界で最も致命的で広範囲にわたる細菌感染症の1つです。数十年以来、多剤および広範囲に薬剤耐性株の突然のバーストは、結核の制御のための深刻な脅威です。そのため、結核の原因 物質である結核 菌(Mtb)にとって重要な新しい標的や経路を特定し、結核薬となりうる新しい化学物質を探ることが不可欠です。1つのアプローチは、干し草の山で針の検索を可能にする大規模なライブラリの遺伝的および化学的スクリーンに適した方法を設定することです。そのために、自動共焦点顕微鏡を用いて蛍光標識された宿主細胞内で蛍光標識 Mtb を検出することに頼る表現型アッセイを開発しました。この インビトロ アッセイは 、Mtbのホストへのコロニー形成プロセスの画像ベースの定量化を可能にし、siRNA-、化学化合物、または Mtb 変異体ライブラリのスクリーンに適した384ウェルマイクロプレート形式に最適化されました。その後、画像はマルチパラメトリック分析のために処理され、宿主細胞内の Mtbの病因に関する読み取り結果を提供します。

ハイスループットゲノムワイドsiRNAスクリーニング
Mtb は、他のいくつかの肺上皮細胞と同様 に、インビトロで 免疫細胞を植民地化することができる。例えば 、Mtbは、ヒトII型肺球5-7のモデルとして一般的に使用されているA549上皮細胞に感染し、損傷を与えることができる。Dectin-1は 、Mtb 取り込み、A549細胞における細胞内抗菌増殖に対?...

Watch this Scientific Journal Video about A Microscopic Phenotypic Assay for the Quantification of Intracellular Mycobacteria Adapted for High-throughput/High-content Screening at JoVE.com

A Microscopic Phenotypic Assay for the Quantification of Intracellular Mycobacteria Adapted for High-throughput/High-content Screening

ここでは、小干渉合成RNA(siRNA)、化学化合物、および 結核 菌変異体ライブラリーのハイスループット/高含有スクリーンに適用可能な表現型アッセイについて述べている。この方法は、自動共焦点顕微鏡を用いた蛍光標識された宿主細胞内の蛍光標識型 結核 の検出に依存している。

高スループット/高含有スクリーニングに適応した細胞内マイコバクテリアの定量化のための顕微鏡表現型アッセイ

Despite the availability of therapy and vaccine, tuberculosis (TB) remains one of the most deadly and widespread bacterial infections in the world. Since ...

a-microscopic-phenotypic-assay-for-quantification-intracellular

Research

JoVE Journal

Immunology and Infection

7.6K ビュー.  Université de Lille. ここでは、小干渉合成RNA(siRNA)、化学化合物、および 結核 菌変異体ライブラリーのハイスループット/高含有スクリーンに適用可能な表現型アッセイについて述べている。この方法は、自動共焦点顕微鏡を用いた蛍光標識された宿主細胞内の蛍光標識型 結核 の検出に依存している。

ビデオ: A Microscopic Phenotypic Assay for the Quantification of Intracellular Mycobacteria Adapted for High-throughput/High-content Screening

A Functional Whole Blood Assay to Measure Viability of Mycobacteria, using Reporter-Gene Tagged BCG or M.Tb (BCG lux/M.Tb lux)

Functional assays have long played a key role in measuring of immunogenicity of a given vaccine. This is conventionally expressed as serum bactericidal titers. Studies of serum bactericidal titers in response to childhood vaccines have enabled us to develop and validate cut-off levels for protective immune responses and such cut-offs are in routine use. No such assays have been taken forward into the routine assessment of vaccines that induce primarily cell-mediated immunity in the form of effector T cell responses, such as TB vaccines. In the animal model, the performance of a given vaccine candidate is routinely evaluated in standardized bactericidal assays, and all current novel TB-vaccine candidates have been subjected to this step in their evaluation prior to phase 1 human trials. The assessment of immunogenicity and therefore likelihood of protective efficacy of novel anti-TB vaccines should ideally undergo a similar step-wise evaluation in the human models now, including measurements in bactericidal assays.
Bactericidal assays in the context of tuberculosis vaccine research are already well established in the animal models, where they are applied to screen potentially promising vaccine candidates. Reduction of bacterial load in various organs functions as the main read-out of immunogenicity. However, no such assays have been incorporated into clinical trials for novel anti-TB vaccines to date.
Although there is still uncertainty about the exact mechanisms that lead to killing of mycobacteria inside human macrophages, the interaction of macrophages and T cells with mycobacteria is clearly required. The assay described in this paper represents a novel generation of bactericidal assays that enables studies of such key cellular components with all other cellular and humoral factors present in whole blood without making assumptions about their relative individual contribution. The assay described by our group uses small volumes of whole blood and has already been employed in studies of adults and children in TB-endemic settings. We have shown immunogenicity of the BCG vaccine, increased growth of mycobacteria in HIV-positive patients, as well as the effect of anti-retroviral therapy and Vitamin D on mycobacterial survival in vitro. Here we summarise the methodology, and present our reproducibility data using this relatively simple, low-cost and field-friendly model.
Note: Definitions/Abbreviations
BCG lux = M. bovis BCG, Montreal strain, transformed with shuttle plasmid pSMT1 carrying the luxAB genes from Vibrio harveyi, under the control of the mycobacterial GroEL (hsp60) promoter. 
CFU = Colony Forming Unit (a measure of mycobacterial viability).

A Functional Whole Blood Assay to Measure Viability of Mycobacteria, using Reporter-Gene Tagged BCG or M.Tb BCG lux/M.Tb lux

We describe an alternative approach to the enumeration of mycobacteria in vitro, which uses reporter-gene tagged mycobacteria instead of colony-forming units (CFU). &#x201C;Survival&#x201D; of organisms as well as host response-markers are measured simultaneously, providing a low-cost, versatile and functional system for studies of host/pathogen interactions in the context of tuberculosis.

BCGまたはM. TB（BCGタグレポーター遺伝子を用いて、抗酸菌の生存率を測定するための機能全血アッセイルクス / M. Tbをルクス）

Functional assays have long played a key role in measuring of immunogenicity of a given vaccine. This is conventionally expressed as serum bactericidal ...

免疫・感染学

A Parasite Rescue and Transformation Assay for Antileishmanial Screening Against Intracellular Leishmania donovani Amastigotes in THP1 Human Acute Monocytic Leukemia Cell Line

Leishmaniasis is one of the world's most neglected diseases, largely affecting the poorest of the poor, mainly in developing countries. Over 350 million people are considered at risk of contracting leishmaniasis, and approximately 2 million new cases occur yearly1. Leishmania donovani is the causative agent for visceral leishmaniasis (VL), the most fatal form of the disease. The choice of drugs available to treat leishmaniasis is limited 2;current treatments provide limited efficacy and many are toxic at therapeutic doses. In addition, most of the first line treatment drugs have already lost their utility due to increasing multiple drug resistance 3. The current pipeline of anti-leishmanial drugs is also severely depleted. Sustained efforts are needed to enrich a new anti-leishmanial drug discovery pipeline, and this endeavor relies on the availability of suitable in vitro screening models.
In vitro promastigotes 4 and axenic amastigotes assays5 are primarily used for anti-leishmanial drug screening however, may not be appropriate due to significant cellular, physiological, biochemical and molecular differences in comparison to intracellular amastigotes. Assays with macrophage-amastigotes models are considered closest to the pathophysiological conditions of leishmaniasis, and are therefore the most appropriate for in vitro screening. Differentiated, non-dividing human acute monocytic leukemia cells (THP1) (make an attractive) alternative to isolated primary macrophages and can be used for assaying anti-leishmanial activity of different compounds against intracellular amastigotes.
Here, we present a parasite-rescue and transformation assay with differentiated THP1 cells infected in vitro with Leishmania donovani for screening pure compounds and natural products extracts and determining the efficacy against the intracellular Leishmania amastigotes. The assay involves the following steps: (1) differentiation of THP1 cells to non-dividing macrophages, (2) infection of macrophages with L. donovani metacyclic promastigotes, (3) treatment of infected cells with test drugs, (4) controlled lysis of infected macrophages, (5) release/rescue of amastigotes and (6) transformation of live amastigotes to promastigotes. The assay was optimized using detergent treatment for controlled lysis of Leishmania-infected THP1 cells to achieve almost complete rescue of viable intracellular amastigotes with minimal effect on their ability to transform to promastigotes. Different macrophage:promastigotes ratios were tested to achieve maximum infection. Quantification of the infection was performed through transformation of live, rescued Leishmania amastigotes to promastigotes and evaluation of their growth by an alamarBlue fluorometric assay in 96-well microplates. This assay is comparable to the currently-used microscopic, transgenic reporter gene and digital-image analysis assays. This assay is robust and measures only the live intracellular amastigotes compared to reporter gene and image analysis assays, which may not differentiate between live and dead amastigotes. Also, the assay has been validated with a current panel of anti-leishmanial drugs and has been successfully applied to large-scale screening of pure compounds and a library of natural products fractions (Tekwani et al. unpublished).

A Parasite Rescue and Transformation Assay for Antileishmanial Screening Against Intracellular Leishmania donovani Amastigotes in THP1 Human Acute Monocytic Leukemia Cell Line

A parasite-rescue and transformation assay with THP1 cells infected in vitro with Leishmania donovani has been optimized for anti-leishmanial drug screening. The assay involves differentiation of THP1 cells, infection with promastigotes, treatment with test drugs, controlled lysis of the infected macrophages, rescue of amastigotes, transformation to promastigotes and monitoring promastigote growth and proliferation with a fluorometric assay.

細胞内の抗リーシュマニアに対するスクリーニングのための寄生虫のRescue and形質転換試験<em&gt;ドノバンリーシュマニア</emTHP1ヒト急性単球性白血病細胞株における&gt;無鞭毛

Leishmaniasis is  one of the world's most neglected diseases, largely affecting the  poorest of the poor, mainly in developing countries. Over 350 million ...

A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes

Directed evolution is defined as a method to harness natural selection in order to engineer proteins to acquire particular properties that are not associated with the protein in nature. Literature has provided numerous examples regarding the implementation of directed evolution to successfully alter molecular specificity and catalysis1. The primary advantage of utilizing directed evolution instead of more rational-based approaches for molecular engineering relates to the volume and diversity of variants that can be screened2. One possible application of directed evolution involves improving structural stability of bacteriolytic enzymes, such as endolysins. Bacteriophage encode and express endolysins to hydrolyze a critical covalent bond in the peptidoglycan (i.e. cell wall) of bacteria, resulting in host cell lysis and liberation of progeny virions. Notably, these enzymes possess the ability to extrinsically induce lysis to susceptible bacteria in the absence of phage and furthermore have been validated both in vitro and in vivo for their therapeutic potential3-5. The subject of our directed evolution study involves the PlyC endolysin, which is composed of PlyCA and PlyCB subunits6. When purified and added extrinsically, the PlyC holoenzyme lyses group A streptococci (GAS) as well as other streptococcal groups in a matter of seconds and furthermore has been validated in vivo against GAS7. Significantly, monitoring residual enzyme kinetics after elevated temperature incubation provides distinct evidence that PlyC loses lytic activity abruptly at 45 &deg;C, suggesting a short therapeutic shelf life, which may limit additional development of this enzyme. Further studies reveal the lack of thermal stability is only observed for the PlyCA subunit, whereas the PlyCB subunit is stable up to ~90 &deg;C (unpublished observation). In addition to PlyC, there are several examples in literature that describe the thermolabile nature of endolysins. For example, the Staphylococcus aureus endolysin LysK and Streptococcus pneumoniae endolysins Cpl-1 and Pal lose activity spontaneously at 42 &deg;C, 43.5 &deg;C and 50.2 &deg;C, respectively8-10. According to the Arrhenius equation, which relates the rate of a chemical reaction to the temperature present in the particular system, an increase in thermostability will correlate with an increase in shelf life expectancy11. Toward this end, directed evolution has been shown to be a useful tool for altering the thermal activity of various molecules in nature, but never has this particular technology been exploited successfully for the study of bacteriolytic enzymes. Likewise, successful accounts of progressing the structural stability of this particular class of antimicrobials altogether are nonexistent. In this video, we employ a novel methodology that uses an error-prone DNA polymerase followed by an optimized screening process using a 96 well microtiter plate format to identify mutations to the PlyCA subunit of the PlyC streptococcal endolysin that correlate to an increase in enzyme kinetic stability (Figure 1). Results after just one round of random mutagenesis suggest the methodology is generating PlyC variants that retain more than twice the residual activity when compared to wild-type (WT) PlyC after elevated temperature treatment.

A novel directed evolution method specific to the field of thermostability engineering was developed and consequently validated for bacteriolytic enzymes. After only one round of random mutagenesis, an evolved bacteriolytic enzyme, PlyC 29C3, displayed greater than twice the residual activity when compared to the wild-type protein after elevated temperature incubation.

耐熱性溶菌酵素の定向進化のための新しいスクリーニング法

Directed evolution is defined as a method to harness natural selection in order to engineer proteins to acquire particular properties that are not ...

Generation and Multi-phenotypic High-content Screening of Coxiella burnetii Transposon Mutants

Invasion and colonization of host cells by bacterial pathogens depend on the activity of a large number of prokaryotic proteins, defined as virulence factors, which can subvert and manipulate key host functions. The study of host/pathogen interactions is therefore extremely important to understand bacterial infections and develop alternative strategies to counter infectious diseases. This approach however, requires the development of new high-throughput assays for the unbiased, automated identification and characterization of bacterial virulence determinants. Here, we describe a method for the generation of a GFP-tagged mutant library by transposon mutagenesis and the development of high-content screening approaches for the simultaneous identification of multiple transposon-associated phenotypes. Our working model is the intracellular bacterial pathogen Coxiellaburnetii, the etiological agent of the zoonosis Q fever, which is associated with severe outbreaks with a consequent health and economic burden. The obligate intracellular nature of this pathogen has, until recently, severely hampered the identification of bacterial factors involved in host pathogen interactions, making of Coxiella the ideal model for the implementation of high-throughput/high-content approaches.

Generation and Multi-phenotypic High-content Screening of Coxiella burnetii Transposon Mutants

Coxiella burnetii is an obligate intracellular Gram-negative bacterium responsible for the zoonotic disease Q fever. Here we describe methods for the generation of Coxiella fluorescent transposon mutants as well as the automated identification and analysis of the resulting internalization, replication and cytotoxic phenotypes.

発生とのマルチ表現型ハイコンテンツスクリーニング<em&gt; Q熱リケッチア</em&gt;トランスポゾン変異体

Invasion and colonization of host cells by bacterial pathogens depend on the activity of a large number of prokaryotic proteins, defined as virulence ...

Visualization of the Charcoal Agar Resazurin Assay for Semi-quantitative, Medium-throughput Enumeration of Mycobacteria

There is an urgent need to discover and progress anti-infectives that shorten the duration of tuberculosis (TB) treatment. Mycobacterium tuberculosis, the etiological agent of TB, is refractory to rapid and lasting chemotherapy due to the presence of bacilli exhibiting phenotypic drug resistance. The charcoal agar resazurin assay (CARA) was developed as a tool to characterize active molecules discovered by high-throughput screening campaigns against replicating and non-replicating M. tuberculosis. Inclusion of activated charcoal in bacteriologic agar medium helps mitigate the impact of compound carry-over, and eliminates the requirement to pre-dilute cells prior to spotting on CARA microplates. After a 7-10 day incubation period at 37 &#176;C, the reduction of resazurin by mycobacterial microcolonies growing on the surface of CARA microplate wells permits semi-quantitative assessment of bacterial numbers via fluorometry. The CARA detects approximately a 2-3 log10 difference in bacterial numbers and predicts a minimal bactericidal concentration leading to &#8805;99% bacterial kill (MBC&#8805;99). The CARA helps determine whether a molecule is active on bacilli that are replicating, non-replicating, or both. Pilot experiments using the CARA facilitate the identification of which concentration of test agent and time of compound exposure require further evaluation by colony forming unit (CFU) assays. In addition, the CARA can predict if replicating actives are bactericidal or bacteriostatic.

The charcoal agar resazurin assay (CARA) is a semi-quantitative, medium-throughput method to assess activity of test agents against mycobacteria that are replicating, non-replicating, or both. The CARA permits rapid evaluation of time- and concentration-dependent activity and identifies parameters to pursue by colony forming unit (CFU) assays.

マイコバクテリアの半定量的、ミディアムスループット列挙のためのチャコール寒天レサズリンアッセイの可視化

There is an urgent need to discover and progress anti-infectives that shorten the duration of tuberculosis (TB) treatment. Mycobacterium tuberculosis, the ...

A Simple Fluorescence Assay for Quantification of Canine Neutrophil Extracellular Trap Release

Neutrophil extracellular traps are networks of DNA, histones and neutrophil proteins released in response to infectious and inflammatory stimuli. Although a component of the innate immune response, NETs are implicated in a range of disease processes including autoimmunity and thrombosis. This protocol describes a simple method for canine neutrophil isolation and quantification of NETs using a microplate fluorescence assay. Blood is collected using conventional venipuncture techniques. Neutrophils are isolated using dextran sedimentation and a density gradient using conditions optimized for dog blood. After allowing time for attachment to the wells of a 96 well plate, neutrophils are treated with NET-inducing agonists such as phorbol-12-myristate-13-acetate or platelet activating factor. DNA release is measured by the fluorescence of a cell-impermeable nucleic acid dye. This assay is a simple, inexpensive method for quantifying NET release, but NET formation rather than other causes of cell death must be confirmed with alternative methods.

Neutrophil extracellular traps (NETs) are networks of DNA, histones and neutrophil proteins. Although a component of the innate immune response, NETs are implicated in autoimmunity and thrombosis. This protocol describes a simple method for canine neutrophil isolation and quantification of NETs using a microplate fluorescence assay.

イヌ好中球細胞外トラップリリースの定量化のためのシンプルな蛍光アッセイ

Neutrophil extracellular traps are networks of DNA, histones and neutrophil proteins released in response to infectious and inflammatory stimuli. Although ...

A Fluorescence-based Lymphocyte Assay Suitable for High-throughput Screening of Small Molecules

High-throughput screening (HTS) is currently the mainstay for the identification of chemical entities capable of modulating biochemical reactions or cellular processes. With the advancement of biotechnologies and the high translational potential of small molecules, a number of innovative approaches in drug discovery have evolved, which explains the resurgent interest in the use of HTS. The oncology field is currently the most active research area for drug screening, with no major breakthrough made for the identification of new immunomodulatory compounds targeting transplantation-related complications or autoimmune ailments. Here, we present a novel in vitro murine fluorescent-based lymphocyte assay easily adapted for the identification of new immunomodulatory compounds. This assay uses T or B cells derived from a transgenic mouse, in which the Nur77 promoter drives GFP expression upon T- or B-cell receptor stimulation. As the GFP intensity reflects the activation/transcriptional activity of the target cell, our assay defines a novel tool to study the effect of given compound(s) on cellular/biological responses. For instance, a primary screening was performed using 4,398 compounds in the absence of a &#34;target hypothesis&#34;, which led to the identification of 160 potential hits displaying immunomodulatory activities. Thus, the use of this assay is suitable for drug discovery programs exploring large chemical libraries prior to further in vitro/in vivo validation studies.

We present in the current study a novel fluorescence-based assay using lymphocytes derived from a transgenic mouse. This assay is suitable for high-throughput screening (HTS) of small molecules endowed with the capacity of either inhibiting or promoting lymphocyte activation.

小分子のハイスループットスクリーニングのための適切な蛍光ベースのリンパ球アッセイ

High-throughput screening (HTS) is currently the mainstay for the identification of chemical entities capable of modulating biochemical reactions or ...

System for Efficacy and Cytotoxicity Screening of Inhibitors Targeting Intracellular Mycobacterium tuberculosis

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is a leading cause of morbidity and mortality worldwide. With the increased spread of multi drug-resistant TB (MDR-TB), there is a real urgency to develop new therapeutic strategies against M. tuberculosis infections. Traditionally, compounds are evaluated based on their antibacterial activity under in vitro growth conditions in broth; however, results are often misleading for intracellular pathogens like M. tuberculosis since in-broth phenotypic screening conditions are significantly different from the actual disease conditions within the human body. Screening for inhibitors that work inside macrophages has been traditionally difficult due to the complexity, variability in infection, and slow replication rate of M. tuberculosis. In this study, we report a new approach to rapidly assess the effectiveness of compounds on the viability of M. tuberculosis in a macrophage infection model. Using a combination of a cytotoxicity assay and an in-broth M. tuberculosis viability assay, we were able to create a screening system that generates a comprehensive analysis of compounds of interest. This system is capable of producing quantitative data at a low cost that is within reach of most labs and yet is highly scalable to fit large industrial settings.

System for Efficacy and Cytotoxicity Screening of Inhibitors Targeting Intracellular Mycobacterium tuberculosis

We have developed a modular high-throughput screening system for discovering novel compounds against Mycobacterium tuberculosis, targeting intracellular and in-broth growing bacteria as well as cytotoxicity against the mammalian host cell.

細胞内の標的阻害剤の有効性及び細胞毒性スクリーニングのためのシステム<em&gt;結核菌</em

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is a leading cause of morbidity and mortality worldwide. With the increased spread ...

Quantification of Intracellular Growth Inside Macrophages is a Fast and Reliable Method for Assessing the Virulence of Leishmania Parasites

The lifecycle of Leishmania, the causative agent of leishmaniasis, alternates between promastigote and amastigote stages inside the insect and vertebrate hosts, respectively. While pathogenic symptoms of leishmaniasis can vary widely, from benign cutaneous lesions to highly fatal visceral disease forms depending on the infective species, all Leishmania species reside inside host macrophages during the vertebrate stage of their lifecycle. Leishmania infectivity is therefore directly related to its ability to invade, survive and replicate within parasitophorous vacuoles (PVs) inside macrophages. Thus, assessing the parasite&#39;s ability to replicate intracellularly serves as a dependable method for determining virulence. Studying leishmaniasis development using animal models is time-consuming, tedious and often difficult, particularly with the pathogenically important visceral forms. We describe here a methodology to follow the intracellular development of Leishmania in bone marrow-derived macrophages (BMMs). Intracellular parasite numbers are determined at 24 h intervals for 72 - 96 h following infection. This method allows for a reliable determination of the effects of various genetic factors on Leishmania virulence. As an example, we show how a single allele deletion of the Leishmania Mitochondrial Iron Transporter gene (LMIT1) impairs the ability of the Leishmania amazonensis mutant strain LMIT1/&#916;Lmit1 to grow inside BMMs, reflecting a drastic reduction in virulence compared to wild-type. This assay also allows precise control of experimental conditions, which can be individually manipulated to analyze the influence of various factors (nutrients, reactive oxygen species, etc.) on the host-pathogen interaction. Therefore, the appropriate execution and quantification of BMM infection studies provide a non-invasive, rapid, economical, safe and reliable alternative to conventional animal model studies.

Quantification of Intracellular Growth Inside Macrophages is a Fast and Reliable Method for Assessing the Virulence of Leishmania Parasites

All pathogenic Leishmania species reside and replicate inside macrophages of their vertebrate hosts. Here, we present a protocol to infect murine bone marrow-derived macrophages in culture with Leishmania, followed by precise quantification of intracellular growth kinetics. This method is useful for studying individual factors influencing host-pathogen interaction and Leishmania virulence.

細胞内マクロファージの内部成長の定量化は高速とリーシュ マニア原虫の病原性を評価するための信頼性の高い方法です。

The lifecycle of Leishmania, the causative agent of leishmaniasis, alternates between promastigote and amastigote stages inside the insect and vertebrate ...

A High-throughput, High-content, Liquid-based C. elegans Pathosystem

The number of new drugs identified by traditional, in vitro screens has waned, reducing the success of this approach in the search for new weapons to combat multiple drug resistance. This has led to the conclusion that researchers do not only need to find new drugs, but also need to develop new ways of finding them. Amongst the most promising candidate methods are whole-organism, in vivo assays that use high-throughput, phenotypic readouts and hosts that range from Caenorhabditis elegans to Danio rerio. These hosts have several powerful advantages, including dramatic reductions in false positive hits, as compounds that are toxic to the host and/or biounavailable are typically dropped in the initial screen, prior to costly follow up.
Here we show how our assay has been used to interrogate host variation in the well-documented C. elegans&#8212;Pseudomonas aeruginosa liquid killing pathosystem. We also demonstrate several extensions of this well-worked out technique. For example, we are able to carry out high-throughput genetic screens using RNAi in 24- or 96-well plate formats to query host factors in this host-pathogen interaction. Using this assay, whole genome screens can be completed in only a few months, which can dramatically simplify the task of identifying drug targets, potentially without the need for laborious biochemical purification approaches.
We also report here a variation of our method that substitutes the gram-positive bacterium Enterococcus faecalis for the gram-negative pathogen P. aeruginosa. Much as is the case for P. aeruginosa, killing by E. faecalis is time-dependent. Unlike previous C. elegans&#8212;E. faecalis assays, our assay for E. faecalis does not require preinfection, improving its safety profile and reducing the chances of contaminating liquid-handling equipment. The assay is highly robust, showing ~95% death rates 96 h post infection.

A High-throughput, High-content, Liquid-based C. elegans Pathosystem

Here we describe a protocol that is an adaptable, whole host, high-content screening tool that can be utilized to study host-pathogen interactions and be used for drug discovery.

高スループット、高コンテンツ、液体ベースのc. の elegans病態システム

The number of new drugs identified by traditional, in vitro screens has waned, reducing the success of this approach in the search for new weapons to ...