PSはBill and Melinda Gates Grand Challenge助成金OPP1141322の受領者です。 PVは、スイス国立科学財団早期ポストドックモビリティフェローシップとRoux-Cantarini博士後援フェローシップによって支えられました。 PJSはHHMIグラントとERC-2013-ADG 339579-Decryptによってサポートされています。

<ol>
	<li>Reineke, L. C., Lloyd, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diversion+of+stress+granules+and+P-bodies+during+viral+infection.">Diversion of stress granules and P-bodies during viral infection.</a> Virology. 436 (2), 255-267 (2013).</li><li>Kedersha, N., Ivanov, P., Anderson, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+granules+and+cell+signaling:+more+than+just+a+passing+phase.">Stress granules and cell signaling: more than just a passing phase.</a> Trends Biochem Sci. 38 (10), 494-506 (2013).</li><li>Vonaesch, P., Campbell-Valois, F. -. X., Dufour, A., Sansonetti, P. J., Schnupf, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shigella+flexneri+modulates+stress+granule+composition+and+inhibits+stress+granule+aggregation.">Shigella flexneri modulates stress granule composition and inhibits stress granule aggregation.</a> Cell Microbiol. 18 (7), 982-997 (2016).</li><li>Kolobova, E., Efimov, 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=Microtubule-dependent+association+of+AKAP350A+and+CCAR1+with+RNA+stress+granules.">Microtubule-dependent association of AKAP350A and CCAR1 with RNA stress granules.</a> Exp Cell Res. 315 (3), 542-555 (2009).</li><li>Anderson, P., Kedersha, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+granules:+the+Tao+of+RNA+triage.">Stress granules: the Tao of RNA triage.</a> Trends in biochemical sciences. 33 (3), 141-150 (2008).</li><li>Anderson, P., Kedersha, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stressful+initiations.">Stressful initiations.</a> J Cell Sci. 115, 3227-3234 (2002).</li><li>Mohr, I., Sonenberg, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Host+translation+at+the+nexus+of+infection+and+immunity.">Host translation at the nexus of infection and immunity.</a> Cell Host Microbe. 12 (4), 470-483 (2012).</li><li>Hu, S., Claud, E. C., Musch, M. W., Chang, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+granule+formation+mediates+the+inhibition+of+colonic+Hsp70+translation+by+interferon-+and+tumor+necrosis+factor.">Stress granule formation mediates the inhibition of colonic Hsp70 translation by interferon- and tumor necrosis factor.</a> Am J Physiol Gastointest Liver Physiol. 298 (4), 481-492 (2010).</li><li>Barry, E. M., Pasetti, M. F., Sztein, M. B., Fasano, A., Kotloff, K. L., Levine, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progress+and+pitfalls+in+Shigella+vaccine+research.">Progress and pitfalls in Shigella vaccine research.</a> Nat Rev Gastroenterol Hepatol. 10 (4), 245-255 (2013).</li><li>Lanata, C. F., Fischer-Walker, C. L., 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=Global+Causes+of+Diarrheal+Disease+Mortality+in+Children.">Global Causes of Diarrheal Disease Mortality in Children.</a> PloS One. 8 (9), 72788 (2013).</li><li>Ashida, H., Ogawa, 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=Shigella+deploy+multiple+countermeasures+against+host+innate+immune+responses.">Shigella deploy multiple countermeasures against host innate immune responses.</a> Curr Opin Microbiol. 14 (1), 16-23 (2011).</li><li>Ashida, H., Ogawa, M., Mimuro, H., Kobayashi, T., Sanada, T., Sasakawa, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shigella+are+versatile+mucosal+pathogens+that+circumvent+the+host+innate+immune+system.">Shigella are versatile mucosal pathogens that circumvent the host innate immune system.</a> Curr Opin Immunol. 23 (4), 448-455 (2011).</li><li>Kedersha, N., Anderson, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mammalian+stress+granules+and+processing+bodies.">Mammalian stress granules and processing bodies.</a> Methods Enzymol. 431, 61-81 (2007).</li><li>Ray, K., Marteyn, B., Sansonetti, P. J., Tang, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Life+on+the+inside:+the+intracellular+lifestyle+of+cytosolic+bacteria.">Life on the inside: the intracellular lifestyle of cytosolic bacteria.</a> Nat Re. Micro. 7 (5), 333-340 (2009).</li></ol>

著者は何も開示することはない。

本明細書に概説されたプロトコルは、外因性ストレスの存在下または非存在下で、非感染細胞および細胞質病原体S.フレクスナーネに感染した細胞におけるSGの誘導、局在化および分析を記載する。フリーイメージングソフトウェアを使用することにより、このプロトコルにより、SG形成の正確な定性および定量分析が可能となり、与えられた表現型の差異を同定および統計的に取り扱?...

細胞レベルでの宿主 - 病原体相互作用の可視化は、病原性戦略への洞察を獲得し、主要な細胞経路を同定するための強力な方法である。事実、病原体は、自身の生存または増殖のための戦略として中央細胞プロセスを破壊するように進化しているので、病原体を重要な細胞標的または構造を特定するためのツールとして使用することができる。細胞成分の可視化は、蛍光標識された宿主タンパク質を組換え発現することによって達成することができる。これはリアルタイム分析を可能にするが、特異的に標識された宿主タンパク質を有する細胞株の生成は非常に面倒であり、望ましくない副作用をもたらし得る。複数の宿主因子を同時に分析することができ、特定の細胞型に限定されないため、特異的抗体を用いた細胞因子の検出がより便利である。欠点は、免疫蛍光分析が宿主細胞固定化を必要とするので、静的視野のみを捕捉できることであるイオン。しかしながら、免疫蛍光イメージングの重要な利点は、それが定性分析および定量分析の両方に容易に役立つことである。これは、次に、宿主 - 病原体相互作用への新しい洞察を提供するために統計的に有意な差異を得るために使用することができる。 蛍光画像解析プログラムは、3Dおよび4D解析を実行するための強力な解析ツールです。しかし、ソフトウェアの高コストとそのメンテナンスは、フリー・オープンソース・ソフトウェアに基づく方法をより広く魅力的にしています。バイオ分析ソフトウェアを使用した慎重な画像分析は、視覚分析を実証し、統計的有意性を割り当てるときに、所与の表現型の正確性に対する信頼性を高めるので有益である。これまで、SGは、個別のSG 4の手動識別を必要とする無料のImageJソフトウェアを使用して分析されていました。ここでは、bacの文脈における細胞SG形成の誘導および分析のためのプロトコルを提供するフリーオープンソースのバイオイメージ分析ソフトウェアICY（http://icy.bioimageanalysis.org）を使用して、腸内感染を検出した。バイオイメージ解析ソフトウェアには、SG解析に非常に適したスポット検出プログラムが組み込まれています。これにより、指定された関心領域（ROI）での自動検出プロセスの微調整が可能になります。これは、個々のSGの手動分析の必要性を克服し、サンプリングバイアスを除去する。 多くの環境ストレスは、直径0.2-5μmの相密度の高いサイトゾル、非膜構造であるSGの形成を誘発する5,6 。この細胞応答は、酵母、植物および哺乳動物において進化的に保存され、全身タンパク質翻訳が阻害される場合に起こる。これは、失活した翻訳開始複合体のSGへの凝集を含み、翻訳的に不活性なmRNAの保持場所と考えられ、細胞mRNAのサブセットの選択的翻訳を可能にする。ストレスを除去すると、SGが溶解し、タンパク質合成の全体的な速度が再開する。 SGは、翻訳伸長開始因子、RNA代謝に関与するタンパク質、RNA結合タンパク質、ならびに宿主細胞シグナリング2に関与するスカフォールドタンパク質および因子からなるが、正確な組成は適用されるストレスに依存して変化し得る。 SG形成を誘発する環境因子には、アミノ酸飢餓、UV照射、熱ショック、浸透圧ショック、小胞体ストレス、低酸素症およびウイルス感染が含まれる2,7,8。ウイルスがどのように誘導され、SGの形成を破壊するかについての理解が進んだが、細菌、真菌、原生動物病原体などの他の病原体がこの細胞ストレス応答にどのように影響するかについてはほとんど知られていない。 シゲIIフレクスナーは、ヒトのグラム陰性通性細胞質ゾル病原体であり、重度の下痢またはシゲラ症の原因物質である。シゲロシスは重大な公衆衛生上の負担であり、5歳未満の小児では毎年28,000人の死亡を引き起こす。 フレックスネリは結腸上皮に感染し、宿主の細胞骨格成分11,12をハイジャックすることにより細胞間拡散を起こす 。上皮の感染は、サイトゾル内でのフレクスネリ（ flexneri）の複製を支持するが、感染マクロファージは、熱中症と呼ばれる炎症性細胞死プロセスによって死ぬ。感染は、熱、酸化ストレスおよび組織破壊を伴う好中球および重度の炎症の大規模な動員につながる。したがって、感染細胞は、ゴルジ破壊、遺伝毒性ストレスおよび細胞骨格再編成などの感染によって誘導される内部ストレスを受ける炎症過程に起因する環境ストレスにさらされる。 多数のSGマーカーを用いて環境ストレスに応答する細胞の能力に対するS.フレックスネリ感染の特徴付けは、感染がSG組成3の定性的および定量的差異をもたらすことを実証した。しかしながら、他の細菌病原体についてはほとんど知られていない。ここでは、異なる環境ストレスを有する細胞のストレス、SG成分の標識、および感染の文脈におけるSGの形成および組成の定性的および定量的分析を含む、細胞質病原菌S.フレックスネリによる宿主細胞の感染のための方法論を説明する。および非感染細胞が含まれる。この方法は、他の細菌病原体に広く適用可能である。さらに、SG形成の画像分析は、ウイルスまたは他の病原体による感染のために使用され得る。それはSGを分析するために使用することができます外因性のストレスに応答したSG形成に対する感染の影響または感染の効果。

<table><tbody><tr><td>&lt;strong&gt;Primary Antibodies&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>eIF3b (N20), origin goat&amp;nbsp;</td><td>Santa Cruz</td><td>sc-16377</td><td>Robust and widely used SG marker. Cytosolic staining allows cell delineation. Dilution 1:300</td></tr><tr><td>eIF3b (A20), origin goat&amp;nbsp;</td><td>Santa Cruz</td><td>sc-16378</td><td>Same target as eIF3b (N20) and in our hands was identical to eIF3b (N20). Dilution 1:300</td></tr><tr><td>eIF3A (D51F4), origin rabbit (MC: monoclonal)</td><td>Cell Signaling</td><td>3411</td><td>Part of multiprotein eIF3 complex with eIF3b . Dilution 1:800</td></tr><tr><td>eIF4AI, origin goat&amp;nbsp;</td><td>Santa Cruz</td><td>sc-14211</td><td>Recommended by (Ref # 13). Dilution 1:200</td></tr><tr><td>eIF4B, origin rabbit</td><td>Abcam</td><td>ab186856</td><td>Good stress granule marker in our hands. Dilution 1:300</td></tr><tr><td>eIF4B, origin rabbit</td><td>Cell Signaling</td><td>3592</td><td>Recommended by Ref # 13. Dilution 1:100</td></tr><tr><td>eIF4G, origin rabbit</td><td>Santa Cruz</td><td>sc-11373</td><td>Widely used SG marker. (Ref # 13): may not work well in mouse cell lines. Dilution 1:300</td></tr><tr><td>G3BP1, origin rabbit (MC: monoclonal)</td><td>BD Biosciences</td><td>611126</td><td>Widely used SG marker. Dilution 1:300</td></tr><tr><td>Tia-1, origin goat&amp;nbsp;</td><td>Santa Cruz</td><td>sc-1751</td><td>Widely used SG marker. Can also be found in P bodies when SG are present (Ref # 13). Dilution 1:300</td></tr><tr><td>&lt;strong&gt;Alexa-conjugated Secondary Antibodies&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>A488 anti-goat , origin donkey</td><td>Thermo Fisher</td><td>A-11055</td><td>Cross absorbed. Dilution 1:500</td></tr><tr><td>A568 anti-goat, origin donkey</td><td>Thermo Fisher</td><td>A-11057</td><td>Cross absorbed. Dilution 1:500</td></tr><tr><td>A488 anti-mouse, origin donkey</td><td>Thermo Fisher</td><td>A-21202</td><td>Dilution 1:500</td></tr><tr><td>A568 anti-mouse, origin donkey</td><td>Thermo Fisher</td><td>A10037</td><td>Dilution 1:500</td></tr><tr><td>A647 anti-mouse, origin donkey</td><td>Thermo Fisher</td><td>A31571</td><td>Dilution 1:500</td></tr><tr><td>A488 anti-rabbit, origin donkey</td><td>Thermo Fisher</td><td>A-21206</td><td>Dilution 1:500</td></tr><tr><td>A568 anti-rabbit, origin donkey</td><td>Thermo Fisher</td><td>A10042</td><td>Dilution 1:500</td></tr><tr><td>&lt;strong&gt;Other Reagents&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>&lt;em&gt;Shigella flexneri&lt;/em&gt;</td><td></td><td></td><td>Available from various laboratories by request</td></tr><tr><td>Tryptone Casein Soya (TCS) broth</td><td>BD Biosciences</td><td>211825</td><td>Standard growth medium for Shigella, application - bacterial growth</td></tr><tr><td>TCS agar</td><td>BD Biosciences</td><td>236950</td><td>Standard growth agar for Shigella, application - bacterial growth</td></tr><tr><td>Congo red</td><td>SERVA Electrophoresis GmbH</td><td>27215.01</td><td>Distrimination tool for Shigell that have lost the virulence plasmid, application - bacterial growth</td></tr><tr><td>Poly-L-Lysine (PLL)</td><td>Sigma-Aldrich</td><td>P1274</td><td>Useful to coating bacteria to increase infection, application - infection</td></tr><tr><td>Gentamicin</td><td>Sigma-Aldrich</td><td>G1397</td><td>Selective killing of extracellular but not cytosolic bacteria, application - infection</td></tr><tr><td>HEPES</td><td>Life Technologies</td><td>15630-056</td><td>PH buffer useful when cells are incubated at RT, application - cell culture</td></tr><tr><td>Dulbecco&#039;s Modified Eagle Medium (DMEM)</td><td>Life Technologies</td><td>31885</td><td>Standard culture medium for HeLa cells, application - cell culture</td></tr><tr><td>Fetal Calf Serum (FCS)</td><td>Biowest</td><td>S1810-100</td><td>5% supplementation used for HeLa cell culture medium, application - cell culture</td></tr><tr><td>Non-Essential Amino Acids (NEAA)</td><td>Life Technologies</td><td>11140</td><td>1:100 dilution used for HeLa cell culture medium, application - cell culture</td></tr><tr><td>DMSO</td><td>Sigma-Aldrich</td><td>D2650</td><td>Reagent diluent, application - cell culture</td></tr><tr><td>Sodium arsenite</td><td>Sigma-Aldrich</td><td>S7400</td><td>Potent stress granule inducer (Note: highly toxic, special handling and disposal required), application - stress inducer</td></tr><tr><td>Clotrimazole</td><td>Sigma-Aldrich</td><td>C6019</td><td>Potent stress granule inducer (Note:health hazard, special handling and disposal required), application - stress inducer</td></tr><tr><td>Paraformaldehyde (PFA</td><td>Electron Microscopy Scences</td><td>15714</td><td>4% PFA is used for standard fixation of cells, application - fixation</td></tr><tr><td>Triton X-100</td><td>Sigma-Aldrich</td><td>T8787</td><td>Used at 0.03% for permeabilizationof host cells before immunofluorescent staining, application - permeabilization</td></tr><tr><td>A647-phalloidin</td><td>Thermo Fisher</td><td>A22287</td><td>Dilution is at 1:40, best added during secondary antibody staining, application - staining</td></tr><tr><td>DAPI</td><td>Sigma-Aldrich</td><td>D9542</td><td>Nucleid acid stain used to visualize both the host nucleus and bacteria, application - staining</td></tr><tr><td>Parafilm</td><td>Sigma-Aldrich</td><td>BR701501</td><td>Paraffin film useful for immunofluorescent staining of coverslips, application - staining</td></tr><tr><td>Prolong Gold</td><td>Thermo Fisher</td><td>36930</td><td>Robust mounting medium that works well for most fluorophores , application - mounting</td></tr><tr><td>Mowiol</td><td>Sigma-Aldrich</td><td>81381</td><td>Cheap and robust mounting medium that works well for most fluorophores, application - mounting</td></tr><tr><td>24-well cell culture plate</td><td>Sigma-Aldrich</td><td>CLS3527</td><td>Standard tissue culture plates, application - cell culture</td></tr><tr><td>12 mm&amp;nbsp; glass coverslips</td><td>NeuVitro</td><td>1001/12</td><td>Cell culture support for immunofluorescent applications, application - cell support</td></tr><tr><td>forceps</td><td>Sigma-Aldrich</td><td>81381</td><td>Cheap and robust mounting medium that works well for most fluorophores, application - mounting</td></tr><tr><td>&lt;strong&gt;Programs and Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Prism</td><td>GraphPad Software</td><td></td><td>Data analysisand graphing program with robust statistical test options, application - data analysis</td></tr><tr><td>Leica SP5</td><td>Leica Microsystems</td><td></td><td>Confocal microsope, application - image acquisition</td></tr><tr><td>Imaris</td><td>Bitplane</td><td></td><td>Professional image analysis program, application - data analysis</td></tr><tr><td>Excel</td><td>Microsoft</td><td></td><td>Data analysis and graphing program, application - data analysis</td></tr></tbody></table>

immunofluorescence analysis of stress granule formation after bacterial challenge of mammalian cells

細胞成分の蛍光イメージングは​​、宿主 - 病原体相互作用を調べるための有効なツールである。病原体は、細胞小器官の超微細構造、細胞骨格のネットワーク構成、ならびにストレス顆粒（SG）形成などの細胞プロセスを含む感染細胞の多くの異なる特徴に影響を及ぼし得る。どのように病原体が宿主プロセスを破壊するかの特徴付けは、病因の分野の重要かつ不可欠な部分である。様々な表現型が容易に目に見えるかもしれないが、病原体チャレンジによって誘発される細胞構造の定性的および定量的差異の正確な分析は、実験試料と対照試料との間に統計学的有意差を定義するために不可欠である。 SGの形成は、進化的に保存されたストレス応答であり、抗ウイルス応答をもたらし、ウイルス感染を用いて長く研究されてきた1 。 SG形成はまた、シグナル伝達カスケードに影響を及ぼし、他の未知のconseq2 。細菌病原体のようなウイルス以外の病原体に対するこのストレス応答の特徴付けは、現在、新たな研究領域3である 。今のところ、ウイルスの系においてさえも、SG形成の定量的および定性的分析はまだ日常的には用いられていない。ここで我々は、様々な外因性ストレスに応答してSGの形成に影響を与える、非感染細胞および細胞質細菌病原体に感染した細胞におけるSG形成を誘発および特徴付けするための簡単な方法を記載する。 SGの形成および組成の分析は、多数の異なるSGマーカーおよびオープンソース画像分析ツールであるICYのスポット検出器プラグインを使用することによって達成される。

この原稿で説明されているプロトコルを説明し、実証するために、本発明者らは、サイトゾル病原菌であるフレクスネリ（flexneri）に感染したか否かにかかわらず、HeLa細胞におけるクロトリマゾール誘発SGのイメージを特徴付けた。手順の概要は図1に示されており、コンゴーレッドプレートにストリーミングされた有毒で無害なフレッ...

Watch this Scientific Journal Video about Immunofluorescence Analysis of Stress Granule Formation After Bacterial Challenge of Mammalian Cells at JoVE.com

Immunofluorescence Analysis of Stress Granule Formation After Bacterial Challenge of Mammalian Cells

本発明者らは、細胞が細菌および多数の異なるストレスでチャレンジされた後の哺乳動物細胞におけるストレス顆粒形成の定性的および定量的分析のための方法を記載する。このプロトコルは、広範囲の宿主 - 細菌相互作用における細胞ストレス顆粒応答を調べるために適用することができる。

哺乳動物細胞の細菌攻撃後のストレス顆粒形成の免疫蛍光分析

Fluorescent imaging of cellular components is an effective tool to investigate host-pathogen interactions. Pathogens can affect many different features of ...

immunofluorescence-analysis-stress-granule-formation-after-bacterial

Research

JoVE Journal

Immunology and Infection

10.1K ビュー.  Institut Pasteur. 本発明者らは、細胞が細菌および多数の異なるストレスでチャレンジされた後の哺乳動物細胞におけるストレス顆粒形成の定性的および定量的分析のための方法を記載する。このプロトコルは、広範囲の宿主 - 細菌相互作用における細胞ストレス顆粒応答を調べるために適用することができる。 

ビデオ: Immunofluorescence Analysis of Stress Granule Formation After Bacterial Challenge of Mammalian Cells

Invasion of Human Cells by a Bacterial Pathogen

Here we will describe how we study the invasion of human endothelial cells by bacterial pathogen Staphylococcus aureus . The general protocol can be applied to the study of cell invasion by virtually any culturable bacterium. The stages at which specific aspects of invasion can be studied, such as the role of actin rearrangement or caveolae, will be highlighted. Host cells are grown in flasks and when ready for use are seeded into 24-well plates containing Thermanox coverslips. Using coverslips allows subsequent removal of the cells from the wells to reduce interference from serum proteins deposited onto the sides of the wells (to which S. aureus would attach). Bacteria are grown to the required density and washed to remove any secreted proteins (e.g. toxins). Coverslips with confluent layers of endothelial cells are transferred to new 24-well plates containing fresh culture medium before the addition of bacteria. Bacteria and cells are then incubated together for the required amount of time in 5% CO2 at 37&deg;C. For S. aureus this is typically between 15-90 minutes. Thermanox coverslips are removed from each well and dip-washed in PBS to remove unattached bacteria. If total associated bacteria (adherent and internalised) are to be quantified, coverslips are then placed in a fresh well containing 0.5% Triton X-100 in PBS. Gentle pipetting leads to complete cell lysis and bacteria are enumerated by serial dilution and plating onto agar. If the number of bacteria that have invaded the cells is needed, coverslips are added to wells containing 500 &mu;l tissue culture medium supplemented with gentamicin and incubation continued for 1 h, which will kill all external bacteria. Coverslips can then be washed, cells lysed and bacteria enumerated by plating onto agar as described above. If the experiment requires direct visualisation, coverslips can be fixed and stained for light, fluorescence or confocal microscopy or prepared for electron microscopy.

A general protocol for the study of invasion of host cells by a bacterial pathogen, focusing on Staphylococcus aureus and human endothelial cells.

細菌性病原体によるヒト細胞の浸潤

Here we will describe how we study the invasion of human endothelial cells by bacterial pathogen Staphylococcus aureus . The general protocol can be ...

免疫・感染学

Stress-induced Antibiotic Susceptibility Testing on a Chip

We have developed a rapid microfluidic method for antibiotic susceptibility testing in a stress-based environment. Fluid is passed at high speeds over bacteria immobilized on the bottom of a microfluidic channel. In the presence of stress and antibiotic, susceptible strains of bacteria die rapidly. However, resistant bacteria survive these stressful conditions. The hypothesis behind this method is new: stress activation of biochemical pathways, which are targets of antibiotics, can accelerate antibiotic susceptibility testing. As compared to standard antibiotic susceptibility testing methods, the rate-limiting step -&#160;bacterial growth -&#160;is omitted during antibiotic application. The technical implementation of the method is in a combination of standard techniques and innovative approaches. The standard parts of the method include bacterial culture protocols, defining microfluidic channels in polydimethylsiloxane&#160;(PDMS), cell viability monitoring with fluorescence, and batch image processing for bacteria counting. Innovative parts of the method are in the use of culture media flow for mechanical stress application, use of enzymes to damage but not kill the bacteria, and use of microarray substrates for bacterial attachment. The developed platform can be used in antibiotic and nonantibiotic related drug development and testing. As compared to the standard bacterial suspension experiments, the effect of the drug can be turned on and off repeatedly over controlled time periods. Repetitive observation of the same bacterial population is possible over the course of the same experiment.

We have developed a microfluidic platform for rapid antibiotic susceptibility testing. Fluid is passed at high speeds over bacteria immobilized on the bottom of a microfluidic channel. In the presence of stress and antibiotic, susceptible strains of bacteria die rapidly. However, resistant bacteria can survive these stressful conditions.

チップ上でのストレス誘発抗生物質感受性試験

We have developed a rapid microfluidic method for antibiotic susceptibility testing in a stress-based environment. Fluid is passed at high speeds over ...

生物工学

Visualizing the Actin and Microtubule Cytoskeletons at the B-cell Immune Synapse Using Stimulated Emission Depletion (STED) Microscopy

B cells that bind to membrane-bound antigens (e.g., on the surface of an antigen-presenting cell) form an immune synapse, a specialized cellular structure that optimizes B-cell receptor (BCR) signaling and BCR-mediated antigen acquisition. Both the remodeling of the actin cytoskeleton and the reorientation of the microtubule network towards the antigen contact site are essential for immune synapse formation. Remodeling of the actin cytoskeleton into a dense peripheral ring of F-actin is accompanied by polarization of the microtubule-organizing center towards the immune synapse. Microtubule plus-end binding proteins, as well as cortical plus-end capture proteins mediate physical interactions between the actin and microtubule cytoskeletons, which allow them to be reorganized in a coordinated manner. Elucidating the mechanisms that control this cytoskeletal reorganization, as well as understanding how these cytoskeletal structures shape immune synapse formation and BCR signaling, can provide new insights into B cell activation. This has been aided by the development of super-resolution microscopy approaches that reveal new details of cytoskeletal network organization. We describe here a method for using stimulated emission depletion (STED) microscopy to simultaneously image actin structures, microtubules, and transfected GFP-tagged microtubule plus-end binding proteins in B cells. To model the early events in immune synapse formation, we allow B cells to spread on coverslips coated with anti-immunoglobulin (anti-Ig) antibodies, which initiate BCR signaling and cytoskeleton remodeling. We provide step-by-step protocols for expressing GFP fusion proteins in A20 B-lymphoma cells, for anti-Ig-induced cell spreading, and for subsequent cell fixation, Immunostaining, image acquisition, and image deconvolution steps. The high-resolution images obtained using these procedures allow one to simultaneously visualize actin structures, microtubules, and the microtubule plus-end binding proteins that may link these two cytoskeletal networks.

Visualizing the Actin and Microtubule Cytoskeletons at the B-cell Immune Synapse Using Stimulated Emission Depletion STED Microscopy

We present a protocol for using STED microscopy to simultaneously image actin structures, microtubules, and microtubule plus-end binding proteins in B cells that have spread on coverslips coated with antibodies to the B-cell receptor, a model for the initial phase of immune synapse formation.

アクチンおよび誘導放出の枯渇 (STED) 顕微鏡を用いた B 細胞免疫シナプスにおける微小管細胞骨格の可視化

B cells that bind to membrane-bound antigens (e.g., on the surface of an antigen-presenting cell) form an immune synapse, a specialized cellular structure ...

A Multi-well Format Polyacrylamide-based Assay for Studying the Effect of Extracellular Matrix Stiffness on the Bacterial Infection of Adherent Cells

Extracellular matrix stiffness comprises one of the multiple environmental mechanical stimuli that are well known to influence cellular behavior, function, and fate in general. Although increasingly more adherent cell types&#39; responses to matrix stiffness have been characterized, how adherent cells&#39; susceptibility to bacterial infection depends on matrix stiffness is largely unknown, as is the effect of bacterial infection on the biomechanics of host cells. We hypothesize that the susceptibility of host endothelial cells to a bacterial infection depends on the stiffness of the matrix on which these cells reside, and that the infection of the host cells with bacteria will change their biomechanics. To test these two hypotheses, endothelial cells were used as model hosts and Listeria monocytogenes as a model pathogen. By developing a novel multi-well format assay, we show that the effect of matrix stiffness on infection of endothelial cells by L. monocytogenes can be quantitatively assessed through flow cytometry and immunostaining followed by microscopy. In addition, using traction force microscopy, the effect of L. monocytogenes infection on host endothelial cell biomechanics can be studied. The proposed method allows for the analysis of the effect of tissue-relevant mechanics on bacterial infection of adherent cells, which is a critical step towards understanding the biomechanical interactions between cells, their extracellular matrix, and pathogenic bacteria. This method is also applicable to a wide variety of other types of studies on cell biomechanics and response to substrate stiffness where it is important to be able to perform many replicates in parallel in each experiment.

We have developed a multi-well format polyacrylamide-based assay for probing the effect of extracellular matrix stiffness on bacterial infection of adherent cells. This assay is compatible with flow cytometry, immunostaining, and traction force microscopy, allowing for quantitative measurements of the biomechanical interactions between cells, their extracellular matrix, and pathogenic bacteria.

付着性のセルの細菌感染症に及ぼす細胞外マトリックス剛性を勉強するためのウェル フォーマット ポリアクリルアミドを用いたアッセイ

Extracellular matrix stiffness comprises one of the multiple environmental mechanical stimuli that are well known to influence cellular behavior, ...

Substructure Analyzer: A User-Friendly Workflow for Rapid Exploration and Accurate Analysis of Cellular Bodies in Fluorescence Microscopy Images

The last decade has been characterized by breakthroughs in fluorescence microscopy techniques illustrated by spatial resolution improvement but also in live-cell imaging and high-throughput microscopy techniques. This led to a constant increase in the amount and complexity of the microscopy data for a single experiment. Because manual analysis of microscopy data is very time consuming, subjective, and prohibits quantitative analyses, automation of bioimage analysis is becoming almost unavoidable. We built an informatics workflow called Substructure Analyzer to fully automate signal analysis in bioimages from fluorescent microscopy. This workflow is developed on the user-friendly open-source platform Icy and is completed by functionalities from ImageJ. It includes the pre-processing of images to improve the signal to noise ratio, the individual segmentation of cells (detection of cell boundaries) and the detection/quantification of cell bodies enriched in specific cell compartments. The main advantage of this workflow is to propose complex bio-imaging functionalities to users without image analysis expertise through a user-friendly interface. Moreover, it is highly modular and adapted to several issues from the characterization of nuclear/cytoplasmic translocation to the comparative analysis of different cell bodies in different cellular sub-structures. The functionality of this workflow is illustrated through the study of the Cajal (coiled) Bodies under oxidative stress (OS) conditions. Data from fluorescence microscopy show that their integrity in human cells is impacted a few hours after the induction of OS. This effect is characterized by a decrease of coilin nucleation into characteristic Cajal Bodies, associated with a nucleoplasmic redistribution of coilin into an increased number of smaller foci. The central role of coilin in the exchange between CB components and the surrounding nucleoplasm suggests that OS induced redistribution of coilin could affect the composition and the functionality of Cajal Bodies.

We present a freely available workflow built for rapid exploration and accurate analysis of cellular bodies in specific cell compartments in fluorescence microscopy images. This user-friendly workflow is designed on the open-source software Icy and also uses ImageJ functionalities. The pipeline is affordable without knowledge in image analysis.

サブ構造アナライザー:蛍光顕微鏡画像における細胞体の迅速な探査と正確な分析のためのユーザフレンドリーなワークフロー

The last decade has been characterized by breakthroughs in fluorescence microscopy techniques illustrated by spatial resolution improvement but also in ...

Multi-scale Analysis of Bacterial Growth Under Stress Treatments

Analysis of the bacterial ability to grow and survive under stress conditions is essential for a wide range of microbiology studies. It is relevant to characterize the response of bacterial cells to stress-inducing treatments such as exposure to antibiotics or other antimicrobial compounds, irradiation, non-physiological pH, temperature, or salt concentration. Different stress treatments might disturb different cellular processes, including cell division, DNA replication, protein synthesis, membrane integrity, or cell cycle regulation. These effects are usually associated with specific phenotypes at the cellular scale. Therefore, understanding the extent and causality of stress-induced growth or viability deficiencies requires a careful analysis of several parameters, both at the single-cell and at the population levels. The experimental strategy presented here combines traditional optical density monitoring and plating assays with single-cell analysis techniques such as flow cytometry and real time microscopy imaging in live cells. This multiscale framework allows a time-resolved description of the impact of stress conditions on the fate of a bacterial population.

This protocol allows a time-resolved description of bacterial growth under stress conditions at the single-cell and the cell population levels.

ストレス治療下での細菌増殖の多スケール分析

Analysis of the bacterial ability to grow and survive under stress conditions is essential for a wide range of microbiology studies. It is relevant to ...

Temporal Quantification of MAPK Induced Expression in Single Yeast Cells

The quantification of gene expression at the single cell level uncovers novel regulatory mechanisms obscured in measurements performed at the population level. Two methods based on microscopy and flow cytometry are presented to demonstrate how such data can be acquired. The expression of a fluorescent reporter induced upon activation of the high osmolarity glycerol MAPK pathway in yeast is used as an example. The specific advantages of each method are highlighted. Flow cytometry measures a large number of cells (10,000) and provides a direct measure of the dynamics of protein expression independent of the slow maturation kinetics of the fluorescent protein. Imaging of living cells by microscopy is by contrast limited to the measurement of the matured form of the reporter in fewer cells. However, the data sets generated by this technique can be extremely rich thanks to the combinations of multiple reporters and to the spatial and temporal information obtained from individual cells. The combination of these two measurement methods can deliver new insights on the regulation of protein expression by signaling pathways.

Two complementary methods based on flow cytometry and microscopy are presented which enable the quantification, at the single cell level, of the dynamics of gene expression induced by the activation of a MAPK pathway in yeast.

シングル酵母細胞中のMAPK誘導発現の時間的な定量

The quantification of gene expression at the  single cell level uncovers novel regulatory mechanisms obscured in measurements  performed at the population ...

生物学

Visualization of G3BP Stress Granules Dynamics in Live Primary Cells

SGs can be visualized in cells by immunostaining of specific protein components or polyA+ mRNAs. SGs are highly dynamic and the study of their assembly and fate is important to understand the cellular response to stress. The deficiency in key factors of SGs like G3BP (RasGAP SH3 domain Binding Protein) leads to developmental defects in mice&#160;and alterations of the Central Nervous System. To study the dynamics of SGs in cells from an organism, one can culture primary cells and follow the localization of a transfected tagged component of SGs. We describe time-lapse experiment to observe G3BP1-containing SGs in Mouse Embryonic Fibroblasts (MEFs). This technique can also be used to study G3BP-containing SGs in live neurons, which is crucial as it was recently shown that these SGs are formed at the onset of neurodegenerative diseases like Alzheimer&#39;s disease. This approach can be adapted to any other cellular body and granule protein component, and performed with transgenic animals, allowing the live study of granules dynamics for example in the absence of a specific factor of these granules.

Stress granules (SGs) are cytoplasmic RNA granules containing stalled ribonucleoprotein particles (RNPs), and important in cellular response to various stresses. Dynamics of SGs can be followed in live cells by visualizing the localization of a tagged component of SGs in transfected primary cells after stress.

ライブ初代細胞におけるG3BPストレス顆粒動態の可視化

SGs can be visualized in cells by immunostaining of specific protein components or polyA+ mRNAs. SGs are highly dynamic and the study of their assembly ...

Methods to Classify Cytoplasmic Foci as Mammalian Stress Granules

Cells are often challenged by sudden environmental changes. Stress Granules (SGs), cytoplasmic ribonucleoprotein complexes that form in cells exposed to stress conditions, are implicated in various aspects of cell metabolism and survival. SGs modulate cellular signaling pathways, post-transcriptional gene expression, and stress response programs. The formation of these mRNA-containing granules is directly connected to cellular translation. SG assembly is triggered by inhibited translation initiation, and SG disassembly is promoted by translation activation or by inhibited translation elongation. This relationship is further highlighted by SG composition. Core SG components are stalled translation pre-initiation complexes, mRNA, and selected RNA-binding Proteins (RBPs). The purpose of SG assembly is to conserve cellular energy by sequestering translationally stalled housekeeping mRNAs, allowing for the enhanced translation of stress-responsive proteins. In addition to the core constituents, such as stalled translation preinitiation complexes, SGs contain a plethora of other proteins and signaling molecules. Defects in SG formation can impair cellular adaptation to stress and can thus promote cell death. SGs and similar RNA-containing granules have been linked to a number of human diseases, including neurodegenerative disorders and cancer, leading to the recent interest in classifying and defining RNA granule subtypes. This protocol describes assays to characterize and quantify mammalian SGs.

Stress Granules (SGs) are nonmembranous cytoplasmic structures that form in cells exposed to a variety of stresses. SGs contain mRNAs, RNA-binding proteins, small ribosomal subunits, translation-related factors, and various cell signaling proteins. This protocol describes a workflow that uses several experimental approaches to detect, characterize, and quantify bona fide SGs.

哺乳類のストレス顆粒としての細胞質叢を分類する方法

Cells are often challenged by sudden environmental changes. Stress Granules (SGs), cytoplasmic ribonucleoprotein complexes that form in cells exposed to ...

An Immunofluorescence Assay to Characterize and Quantify Mammalian Stress Granules

Source: Aulas, A. et al., <a href="https://app.jove.com/v/55656">Methods to Classify Cytoplasmic Foci as Mammalian Stress Granules.</a>&#160;J. Vis. Exp. (2017)
This video demonstrates an assay for characterizing and quantifying mammalian stress granules, which consist of mRNAs, RNA-binding proteins (RBPs), and various other proteins.

哺乳類のストレス顆粒の特性評価と定量のための免疫蛍光アッセイ

1. Cell Preparation

	Add autoclaved coverslips to 12 wells of a 24-well plate, as indicated in&#160;Figure 1A; this can be done using a sterile Pasteur ...

哺乳動物細胞の細菌攻撃後のストレス顆粒形成の免疫蛍光分析

要約

さらに動画を探す

この動画の章

細菌性病原体によるヒト細胞の浸潤

チップ上でのストレス誘発抗生物質感受性試験

アクチンおよび誘導放出の枯渇 (STED) 顕微鏡を用いた B 細胞免疫シナプスにおける微小管細胞骨格の可視化

付着性のセルの細菌感染症に及ぼす細胞外マトリックス剛性を勉強するためのウェルフォーマットポリアクリルアミドを用いたアッセイ

サブ構造アナライザー:蛍光顕微鏡画像における細胞体の迅速な探査と正確な分析のためのユーザフレンドリーなワークフロー

ストレス治療下での細菌増殖の多スケール分析

シングル酵母細胞中のMAPK誘導発現の時間的な定量

ライブ初代細胞におけるG3BPストレス顆粒動態の可視化

哺乳類のストレス顆粒としての細胞質叢を分類する方法

哺乳類のストレス顆粒の特性評価と定量のための免疫蛍光アッセイ

哺乳動物細胞の細菌攻撃後のストレス顆粒形成の免疫蛍光分析

要約

さらに動画を探す

この動画の章

細菌性病原体によるヒト細胞の浸潤

チップ上でのストレス誘発抗生物質感受性試験

アクチンおよび誘導放出の枯渇 (STED) 顕微鏡を用いた B 細胞免疫シナプスにおける微小管細胞骨格の可視化

付着性のセルの細菌感染症に及ぼす細胞外マトリックス剛性を勉強するためのウェル フォーマット ポリアクリルアミドを用いたアッセイ

サブ構造アナライザー:蛍光顕微鏡画像における細胞体の迅速な探査と正確な分析のためのユーザフレンドリーなワークフロー

ストレス治療下での細菌増殖の多スケール分析

シングル酵母細胞中のMAPK誘導発現の時間的な定量

ライブ初代細胞におけるG3BPストレス顆粒動態の可視化

哺乳類のストレス顆粒としての細胞質叢を分類する方法

哺乳類のストレス顆粒の特性評価と定量のための免疫蛍光アッセイ

付着性のセルの細菌感染症に及ぼす細胞外マトリックス剛性を勉強するためのウェルフォーマットポリアクリルアミドを用いたアッセイ