The authors acknowledge the Microscopy core facility at the Faculty of Health Sciences, Link&#246;ping University for providing access to advanced imaging systems; Karl-Eric Magnusson (Emeritus Scientist) at the Dept. of Clinical and Experimental Medicine, Link&#246;ping University for providing access to Imaris 3D/4D image processing software (Bitplane, Switzerland); and S. Braian for his help with the lung model cartoon. This work was supported by funds from the Swedish Research Council (Alternatives to animal research, 2012-1951) and Swedish Research Council (2012-3349) to M.L. and Swedish Foundation for Strategic Research to S.B. S.B. receive grants from the Karolinska Institutet, Swedish Research Council, the Swedish International Development Cooperation Agency (Sida) and the Swedish Civil Contingencies Agency (MSB), and the Swedish Heart and Lung Foundation (HLF). M.S. received grants from the Karolinska Institutet and Stockholm County Council.

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The authors declare no competing financial interests.

The ability to recruit and form organized cell clusters at the site of infection is the hallmark of human TB 11. These dynamic structures known as tubercle granulomas primarily consist of immune cells (macrophages, monocytes, T-cells and B-cells) and multi-nucleated giant cells surrounding M. tuberculosis. The role of the granuloma has long been considered to wall off the infection, preventing local spread of bacteria. However, more recent studies show that granuloma formation is critical for early bacterial survival, growth and dissemination 12. A strategy of new studies is to identify molecules or pathways that could efficiently be targeted to inhibit the cellular migration in granuloma formation and/or TB dissemination. 
A caveat for novel studies on TB is the lack of models that recapitulate human TB. The most widely used experimental animals do not form true granuloma upon M. tuberculosis infection, and are therefore not appropriate choices for studies of TB 13-16. Non-human primates have the closest resemblance to human TB 17, but are not the preferred choice owing to high operational costs and ethical issues. Human TB is a complex immunological process and is difficult to model in vitro. Cell cultures of monolayers or co-cultures lack the 3D environment and tissue responses. Therefore, we have developed an innovative lung tissue model based on human primary immune cells and human lung-specific cell lines 8,9. The model displays characteristic features of human lung tissue, including epithelia with evenly integrated macrophages, formation of extracellular matrix, stratified epithelia and mucus secretion 9. 
The 3D human lung tissue model has several benefits over the in vitro single or co-cultures seeded on tissue culture plates or transwell inserts. First, the human lung-specific cells (fibroblasts and epithelial cells) are not commonly included in the in vitro single or co-cultures. Second, the immune cells and lung-specific cells are embedded in a 3D physiological context (collagen rich extra-cellular matrix products). The response of cells to a stimulus/infection and the migratory behaviour of cells, for instance formation of a granuloma, differ significantly between a 2D and 3D environment. Furthermore, the described method enables the 3D visualization and robust 3D quantitative analysis that provides pivotal information on spatial distribution and intricate cellular interactions. 
Experimental infection in the model tissue with M. tuberculosis resulted in clustering of macrophages at the site of infection, reminiscent of early TB granuloma (Figure 2 and 3). We have recently demonstrated that mutant strains defective in the ability to secrete the virulence factor ESAT-6 or Mycobacterium bovis BCG that lacks ESAT-6 did not induce the clustering of monocytes (no early granuloma), in contrast to the virulent M. tuberculosis 9. These data are consistent with the observations made from Mycobacterium marinum-infected zebrafish embryos, whose transparency allows for elegant live imaging of granuloma formation 12. As there is no gold-standard model for TB, we took advantage of the surgically resected tissue biopsies from TB patients for validation of the method 9. Our in vitro tissue model shares several characteristics with the lung and lymph node biopsies from TB patients, including the aggregation of macrophages in granuloma, the presence of both intra- and extracellular bacteria 18 and induction of necrosis 11. 
Although the described model has physiological relevance to human TB and has several advantages over other in vitro models, it has some limitations. For instance, out of more than 20 collagen proteins identified in humans, only type I is included to the model to mimic the extra-cellular matrix. However, type I collagen is a complex mixture of extra-cellular matrix products and is the most abundant collagen in the human body. Further, we have demonstrated the presence of collagen IV and several extra-cellular matrix proteins such as tropoelastin, vimentin and laminin, which are produced by the epithelial cells and fibroblasts in the tissue model, indicating the synthesis of new collagen 8. Presently, the lung tissue model only has monocytes and macrophages, besides lung-specific cells. It lacks neutrophils and lymphocytes that are also known to be present in the granuloma. Remarkably the model is not limited to the introduction of additional immune cells and is of interest to explore how they contribute to the complex cellular interactions in human TB. Implantation of primary alveolar macrophages, skin-specific cells and lung carcinoma cells has already been tested in the model. Since our objective was to use a model that closely resembles human TB, introduction of mouse cells have not been attempted.
In summary, the lung tissue model has implications for both basic mechanistic and applied studies. Potential applications of the lung model include the study of innate immunity, investigating mechanistic aspects of host defences such as phagosomal maturation, autophagy, production of cytokines, chemokines and anti-microbial peptides, and functional characterization of individual cell types. Strikingly, the in vitro tissue model allows manipulation of one or more cells types and provides a relevant tissue micro-environment, not only for studies on TB, but for a variety of infectious and non-infectious diseases that affect the lungs.

ヒトでは、感染症、組織炎症、細胞の動員、組織リモデリングおよび組織の恒常性の調節に応答が異なる細胞型が関与する複雑な事象です。したがって、これらの方法は、最高の局所組織環境において研究されています。以前は、これは、主に実験動物モデルを使用して可能でした。彼らはしばしば、人間とは異なる方法で病原体に対応し、また、疾患1の別のコースを表示しかし、広く使用されている実験動物は、多くの制限を保持します。 インビトロの肺組織モデル中のヒトはヒト肺で特異的免疫応答を研究するための可能性を保持しています。 ヒト結核感染（TB）は、主に肺に影響を与える病気である。 結核菌 （ 結核菌 ）、結核の原因物質は、細菌が肺dendriに飲み込まれている肺胞腔に輸送されるエアロゾル液滴を経由して肺に達します感染2,3に対する自然免疫応答の一部として、チック細胞や肺胞マクロファージ。病原体の食作用はファゴソーム内のバグの区画化につながる、理想的には食細胞による中和および病原体を死滅させることになります。 Mに曝露された個体の50％まで結核は、先天性免疫応答4を介して感染をクリアすることができると考えられています。感染の他の結果は後の段階で適応免疫系によるクリアランス、潜伏感染またはアクティブな疾患5慢性最悪のケースです。 以前は人間の結核の研究のために何のインビトロ組織モデルは存在していません。ヒトマクロファージまたは他の末梢血細胞の単一細胞培養物は、多くの場合、6,7を使用されています。このアプローチの欠点は、Mに露出し、肺組織内で一緒に動作して、異なる細胞型の動態を反映することができないことです結核 </eM&gt;。したがって、TB上の機能とメカニズムの研究を行うことができるようにするインビトロモデルが必要とされています。セル・ベースのここで説明する体外ヒト肺組織モデルでは、もともとの樹状細胞の機能8の研究のために私たちのグループによって設立されました。私たちは、結核の研究のために、この方法を適応しています。 ここに提示されたヒト肺組織モデルは、組織特異的な上皮細胞および線維芽細胞8から成ります。これらの細胞は、トランスウェルインサート中の多孔質膜の上に、コラーゲンマトリックス中で培養され、フォーム構造は、正常なヒトの肺組織（ 図1）に似ています。空気にさらされると細胞は頂端側8に粘液を分泌し始めます。 M.に感染したヒト初代マクロファージを注入することにより、モデルへの結核 、我々は、免疫細胞が組織に移行し、結核性肉芽腫9の初期段階を形成する方法を観察しています。これは最初のヒト組織モデルDESCRです結核ibed、それが結核と肺の他の疾患に対する自然免疫応答を研究するための有望なツールをもたらします。これまでに、我々は、モデルにおいて免疫細胞としてのみ単球およびマクロファージを使用しているが、複雑さのレベルは、追加の関連する細胞型を含めることによって増加させることができます。 <img alt="図1" src="/files/ftp_upload/53084/53084fig1.jpg" /> 肺組織モデルの概略1.概略図。 （A）モデルM.、ヒト肺特異的上皮細胞で構成されています結核は、初代マクロファージをに感染し、赤色の色素ラベルされた単球をトランスウェルフィルター上に作製したコラーゲン埋め込 ​​まれた線維芽細胞上に播種。空気への組織モデルの露出は、上皮によって細胞外マトリックスタンパク質の産生、粘液分泌と層化を開始します。こうして開発された3次元組織モデルは 、M を研究するための便利なツールですCLO環境における結核感染SELYヒトの肺。（B）組織モデルの製造における様々なステップの代表的な顕微鏡像。（C）肺モデル組織切片の完全な構造に似ています。スケール- 。100ミクロン<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53084/53084fig1large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a>

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Cell culture inserts</td>
			<td>BD Falcon</td>
			<td>353092</td>
			<td></td>
		</tr>
		<tr>
			<td>6-well culture plates</td>
			<td>BD Falcon</td>
			<td>353046</td>
			<td></td>
		</tr>
		<tr>
			<td>MRC-5 cells, lung fibroblasts</td>
			<td></td>
			<td></td>
			<td>ATCC#CCL-171</td>
		</tr>
		<tr>
			<td>16HBE cells, lung epithelial cells</td>
			<td></td>
			<td></td>
			<td>Gift from Dr. Dieter Gruenert, Mt. Zion Cancer Center, University of California, San Fransisco, USA&#160;</td>
		</tr>
		<tr>
			<td>5 x Dulbecco&#8217;s modified Eagle&#8217;s medium (5 x DMEM)</td>
			<td>Gibco</td>
			<td>12800-082</td>
			<td>Made from powder but add 5 times less water. Adjust pH to 7.3 and filter it using a 0.2 &#181;m filter.</td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s modified Eagle&#8217;s medium with glucose (DMEM) 1x</td>
			<td>Gibco</td>
			<td>41965-039</td>
			<td></td>
		</tr>
		<tr>
			<td>Minimum Essential Medium (MEM) 1x with Earle&#8217;s salts</td>
			<td>Sigma</td>
			<td>M4655</td>
			<td></td>
		</tr>
		<tr>
			<td>Non-Essential Amino Acids Solution, 100x</td>
			<td>Life Technologies</td>
			<td>11140-035</td>
			<td></td>
		</tr>
		<tr>
			<td>L-glutamine 200 mM (100x)</td>
			<td>Gibco</td>
			<td>25030-024</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Pyruvate</td>
			<td>Life Technologies</td>
			<td>11360-039</td>
			<td></td>
		</tr>
		<tr>
			<td>NaHCO3 (71.2 mg/ml)</td>
			<td></td>
			<td></td>
			<td>Prepared in house</td>
		</tr>
		<tr>
			<td>Heat inactivated Fetal Bovine Serum (FBS)</td>
			<td>Gibco</td>
			<td>10270-106</td>
			<td>Heat inactivated for 30 min, 56 &#176;C</td>
		</tr>
		<tr>
			<td>Gentamicin (50 mg/ml)</td>
			<td>Gibco</td>
			<td>15750-060</td>
			<td></td>
		</tr>
		<tr>
			<td>Hepes buffer solution 1M</td>
			<td>Gibco</td>
			<td>15630-056</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin Streptomycin (Pen Strep)</td>
			<td>Gibco</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Lymphoprep</td>
			<td>Axis-Shield</td>
			<td>7801</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultrapure 0.5 M EDTA</td>
			<td>Gibco</td>
			<td>15575</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Collagen PA treated (500 ml)</td>
			<td>Organogenesis</td>
			<td>200-055</td>
			<td></td>
		</tr>
		<tr>
			<td>Pure col purified Bovine Collagen solution (100 ml)</td>
			<td>Advanced biomatrix</td>
			<td>5005-B</td>
			<td></td>
		</tr>
		<tr>
			<td>Extracellular matrix protein, Fibronectin (1 mg)</td>
			<td>BD</td>
			<td>354008</td>
			<td></td>
		</tr>
		<tr>
			<td>Primary human monocytes/macrophages</td>
			<td></td>
			<td></td>
			<td>Isolated from human whole blood or buffy coats.</td>
		</tr>
		<tr>
			<td>PKH26 Red fluorescent cell linker</td>
			<td>Sigma</td>
			<td>MINI26</td>
			<td></td>
		</tr>
		<tr>
			<td>Mycobacterium tuberculosis H37Rv expressing green fluorescent protein</td>
			<td></td>
			<td></td>
			<td>M. tuberculosis H37Rv wild type was transformed with the pFPV2 plasmid constitutively expressing GFP.</td>
		</tr>
		<tr>
			<td>Middlebrook 7H9 medium&#160;</td>
			<td>Difco</td>
			<td>271310</td>
			<td></td>
		</tr>
		<tr>
			<td>BBL Middlebrook ADC Enrichment</td>
			<td>BBL</td>
			<td>211887</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween-80</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Kanamycin B sulfate (20 &#181;g/ml)</td>
			<td>Sigma</td>
			<td>B5264</td>
			<td></td>
		</tr>
		<tr>
			<td>Prolong Gold anti=-fade reagent with DAPI</td>
			<td>Invitrogen</td>
			<td>P36935</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin -EDTA</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine serum albumin</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>LSM700 Confocal microscope</td>
			<td>Zeiss</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>iMaris Scientific 3D/4D image processing software, version 7.6.8</td>
			<td>Bitplane AG</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

a 3d human lung tissue model for functional studies on mycobacterium tuberculosis infection

結核（TB）は依然として世界の人々の健康に大きな脅威を保持し、私たちは病気のメカニズムを理解し、新たな治療選択肢の発見を進める手助けするためのコスト効率に優れたが、信頼性の高いモデルの必要性がある。単層のインビトロ細胞培養または共培養は、三次元（3D）環境および組織応答を欠いています。ここで、我々は結核菌 （ 結核菌 ）の感染の間に起こる複雑な事象を研究するための有効なツールであることが期待されているヒト肺組織のインビトロモデルで革新的なについて説明します。 3次元組織モデルは、多孔質膜の上に、コラーゲンマトリックス中で培養された組織特異的上皮細胞および線維芽細胞からなります。空気暴露されると、上皮細胞層別化し、頂端側の粘液を分泌します。 M.に感染したヒト初代マクロファージを導入することにより組織モードに結核lは、我々は、免疫細胞が感染組織中に移動し、TBの肉芽腫の初期段階を形成することが示されています。これらの構造は根本的に異なるか、一般的に広く使用されている実験動物モデルにおいて観察されていない人間の結核、肉芽腫の明確な特徴を再現。この器官培養法は、宿主細胞病原体相互作用の空間的および時間的機能に関する重要な情報を提供する3次元可視化と堅牢な定量分析を可能にします。まとめると、肺組織モデルは、結核の研究のための生理学的に関連する組織の微小環境を提供します。従って、肺組織モデルは、基本的な機構的および応用研究の両方のための潜在的な意味を持ちます。重要なことには、モデルは、それによって、肺に影響を与える感染症の様々なモデル化するためのその使用が広がり、個々の細胞型の添加または操作を可能にします。

ヒトの結核のための3D肺組織モデルは、効果的にMの宿主-病原体相互作用を研究するために使用することができ結核感染 。この方法の基本的な手順は、異なるステップ及び組織切片の全体的な微細構造の代表的な顕微鏡写真を図1に概説されている。このモデルは肺線維芽細胞、気管支上皮細胞および初代単球/マクロファージを含むヒト肺組織のいくつかの構成要素を有しています3D組織環境内に埋め込まれました。ヒト肺組織の構成要素を組み込むだけでなく、モデルは、生理的条件に上皮および粘液分泌のすなわち成層に似ています。 TB感染の監視に肺組織モデルの使用の例は、図2に示されている。M.を視覚化するため結核 -immune細胞遊走との相互作用は、我々 は 、Mに感染したマクロファージを導入しましたGFPを発現する結核組織モデル（核について染色ブルー、DAPI）に合わせて新たに単離したPKH26標識単球（赤）と（緑）。 Mの 7日後の追加について組織モデルに結核に感染した細胞は、共焦点顕微鏡は、人間の結核9の特徴的な病変を模倣感染（緑）のサイト（ 図2）、で赤単球のクラスターを明らかにしています。 Mの 3次元可視化のための代表的な一連の画像結核は、細胞クラスターの組織モデルと定量化は、図3に示されているに感染し。3Dビジュアライゼーションは、3D画像にいくつかの機能を、対話調べ、定量化するため、ユーザーの柔軟性を提供します。 M.部位で単球のクラスターを明らかに図3Bに示すように、緑と赤の細菌単球クラスタの空間的配置は、頂端の回転及び側面図から分かるよう結核。クラスター OBませんでした感染していない組織 （ 図3A）で提供しています。個々の単球の数がMに（p &lt;0.01）減少し、我々は、単球細胞集団のサイズと数を定量した （p &lt;0.001）、細胞塊の大きさ（体積）が増強されることを見出しました結核は感染していない組織モデル（ 図3Cおよび3D）と比較して組織を感染させました。このデータは、Mの初期の肉芽腫形成の我々の以前の発見を検証します結核感染は、2D組織切片9で分析肺組織モデルで観察しました。 我々のデータは、組織モデルは、M細胞-複雑なホストを調査するために自然な立体生息地を提供していることを示唆しています結核の通信ネットワーク。また、3次元可視化と定量分析は、組織モデル（ 図3）の機能を研究するための優れたツールであることがわかりました。細胞塊の定量化（例えば、肉芽腫）、多くの場合、ストレッチ<html>いくつかの細胞層のHESとは完全に3次元定量分析によって捕捉することができます。また、モデル内の個々の細胞や細菌の正確な空間的および時間的特徴の可視化は、指定された実験室でのライブイメージング、移動および追跡調査を可能にします。 <img alt="図2" src="/files/ftp_upload/53084/53084fig2.jpg" /> 病原性M.周囲の組織モデルクラスター図2.単球結核。感染していないと、Mの代表的な共焦点画像結核に感染した組織モデルが提示されています。感染していない組織と比較して、パネルの緑色から（M. tuberculosis- GFP）、赤（PKH26標識単球）、青（DAPI染色核）と合併チャネルが感染組織における単球の動員を示します。スケール - 100μmです。large.jpg &quot;スタイル=&quot;フォントサイズ：14px;行の高さ：28px; &quot;ターゲット=&quot; _空白 &quot;&gt;この図の拡大版をご覧になるにはこちらをクリックしてください。 <img alt="図3" src="/files/ftp_upload/53084/53084fig3.jpg" /> 図3. 3次元可視化と組織モデルの定量分析は、有用な情報を提供しています。全体の組織モデル（A）非感染組織の3次元可視化の代表的な画像、（B）に感染したM.結核、IMARIS画像処理ソフトウェア（バージョン7.6.8）によりツァイスLSM700共焦点顕微鏡および定量分析を用いた光学セクショニングを介し。これらの画像は20X倍率で取得された、頂端、回転水平、回転、垂直および側面図（AとB）からの可視化を可能にする、1.5μmの間隔で19.5ミクロンの組織の厚さをカバーする14のzスタック。（C）QUA単球細胞クラスターのntitative分析はM.後早期肉芽腫クラスタの増強した（p &lt;0.0001）のサイズを明らかに感染組織で複数のクラスタを繰り返し強調、感染していない組織と比較して、感染の不在に比べ結核感染 。（D）単球数の定量は、感染組織の減少した（p &lt;0.01）を示しました。グリーン- M.結核 -GFP、レッド- PKH26標識単球、ブルー-細胞核、スケール- 。100ミクロン<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53084/53084fig3large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a>

Watch this Scientific Journal Video about A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection at JoVE.com

A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection

Human tuberculosis infection is a complex process, which is difficult to model in vitro. Here we describe a novel 3D human lung tissue model that recapitulates the dynamics that occur during infection, including the migration of immune cells and early granuloma formation in a physiological environment.

上の機能的研究のための3Dヒト肺組織モデル<em&gt;結核菌</em&gt;感染

Tuberculosis (TB) still holds a major threat to the health of people worldwide, and there is a need for cost-efficient but reliable models to help us ...

a-3d-human-lung-tissue-model-for-functional-studies-on-mycobacterium

Nanyang Technological University

Research

JoVE Journal

Immunology and Infection

A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection

18.8K ビュー.  Linköping University. Human tuberculosis infection is a complex process, which is difficult to model in vitro. Here we describe a novel 3D human lung tissue model that recapitulates the dynamics that occur during infection, including the migration of immune cells and early granuloma formation in a physiological environment.

ビデオ: A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection

Sample Preparation of Mycobacterium tuberculosis Extracts for Nuclear Magnetic Resonance Metabolomic Studies

Mycobacterium tuberculosis is a major cause of mortality in human beings on a global scale. The emergence of both multi- (MDR) and extensively-(XDR) drug-resistant strains threatens to derail current disease control efforts. Thus, there is an urgent need to develop drugs and vaccines that are more effective than those currently available. The genome of M. tuberculosis has been known for more than 10 years, yet there are important gaps in our knowledge of gene function and essentiality. Many studies have since used gene expression analysis at both the transcriptomic and proteomic levels to determine the effects of drugs, oxidants, and growth conditions on the global patterns of gene expression. Ultimately, the final response of these changes is reflected in the metabolic composition of the bacterium including a few thousand small molecular weight chemicals. Comparing the metabolic profiles of wild type and mutant strains, either untreated or treated with a particular drug, can effectively allow target identification and may lead to the development of novel inhibitors with anti-tubercular activity. Likewise, the effects of two or more conditions on the metabolome can also be assessed. Nuclear magnetic resonance (NMR) is a powerful technology that is used to identify and quantify metabolic intermediates. In this protocol, procedures for the preparation of M. tuberculosis cell extracts for NMR metabolomic analysis are described. Cell cultures are grown under appropriate conditions and required Biosafety Level 3 containment,1 harvested, and subjected to mechanical lysis while maintaining cold temperatures to maximize preservation of metabolites. Cell lysates are recovered, filtered sterilized, and stored at ultra-low temperatures. Aliquots from these cell extracts are plated on Middlebrook 7H9 agar for colony-forming units to verify absence of viable cells. Upon two months of incubation at 37 &deg;C, if no viable colonies are observed, samples are removed from the containment facility for downstream processing. Extracts are lyophilized, resuspended in deuterated buffer and injected in the NMR instrument, capturing spectroscopic data that is then subjected to statistical analysis. The procedures described can be applied for both one-dimensional (1D) 1H NMR and two-dimensional (2D) 1H-13C NMR analyses. This methodology provides more reliable small molecular weight metabolite identification and more reliable and sensitive quantitative analyses of cell extract metabolic compositions than chromatographic methods. Variations of the procedure described following the cell lysis step can also be adapted for parallel proteomic analysis.

Sample Preparation of Mycobacterium tuberculosis Extracts for Nuclear Magnetic Resonance Metabolomic Studies

The metabolomic profile of Mycobacterium tuberculosis is determined after growth in broth cultures. Conditions can be varied to test the effects of nutritional supplements, oxidants, and anti-tuberculosis agents on the metabolic profile of this microorganism. Procedure for extract preparation is applicable for both 1D 1H and 2D 1H-13C NMR analyses.

のサンプル調製<em&gt;結核菌</em核磁気共鳴代謝研究のための&gt;抽出

Mycobacterium tuberculosis is a major cause of mortality in human beings on a global scale. The emergence of both multi- (MDR) and extensively-(XDR) ...

免疫・感染学

Growth of Mycobacterium tuberculosis Biofilms

Mycobacterium tuberculosis, the etiologic agent of human tuberculosis, has an extraordinary ability to survive against environmental stresses including antibiotics. Although stress tolerance of M. tuberculosis is one of the likely contributors to the 6-month long chemotherapy of tuberculosis 1, the molecular mechanisms underlying this characteristic phenotype of the pathogen remain unclear. Many microbial species have evolved to survive in stressful environments by self-assembling in highly organized, surface attached, and matrix encapsulated structures called biofilms 2-4. Growth in communities appears to be a preferred survival strategy of microbes, and is achieved through genetic components that regulate surface attachment, intercellular communications, and synthesis of extracellular polymeric substances (EPS) 5,6. The tolerance to environmental stress is likely facilitated by EPS, and perhaps by the physiological adaptation of individual bacilli to heterogeneous microenvironments within the complex architecture of biofilms 7.
In a series of recent papers we established that M. tuberculosis and Mycobacterium smegmatis have a strong propensity to grow in organized multicellular structures, called biofilms, which can tolerate more than 50 times the minimal inhibitory concentrations of the anti-tuberculosis drugs isoniazid and rifampicin 8-10. M. tuberculosis, however, intriguingly requires specific conditions to form mature biofilms, in particular 9:1 ratio of headspace: media as well as limited exchange of air with the atmosphere 9. Requirements of specialized environmental conditions could possibly be linked to the fact that M. tuberculosis is an obligate human pathogen and thus has adapted to tissue environments. In this publication we demonstrate methods for culturing M. tuberculosis biofilms in a bottle and a 12-well plate format, which is convenient for bacteriological as well as genetic studies. We have described the protocol for an attenuated strain of M. tuberculosis, mc27000, with deletion in the two loci, panCD and RD1, that are critical for in vivo growth of the pathogen 9. This strain can be safely used in a BSL-2 containment for understanding the basic biology of the tuberculosis pathogen thus avoiding the requirement of an expensive BSL-3 facility. The method can be extended, with appropriate modification in media, to grow biofilm of other culturable mycobacterial species.
Overall, a uniform protocol of culturing mycobacterial biofilms will help the investigators interested in studying the basic resilient characteristics of mycobacteria. In addition, a clear and concise method of growing mycobacterial biofilms will also help the clinical and pharmaceutical investigators to test the efficacy of a potential drug.

Growth of Mycobacterium tuberculosis Biofilms

Mycobacterium tuberculosis forms drug tolerant biofilms when cultured in certain conditions. Here we describe methods for culturing M. tuberculosis biofilms and determining the frequency of drug tolerant persisters. These protocols will be useful for further studies into the mechanisms of drug tolerance in M. tuberculosis.

の成長結核バイオフィルム

Mycobacterium tuberculosis, the etiologic agent of human tuberculosis, has an extraordinary ability to survive against environmental stresses including ...

Flow Cytometric Isolation of Primary Murine Type II Alveolar Epithelial Cells for Functional and Molecular Studies

Throughout the last years, the contribution of alveolar type II epithelial cells (AECII) to various aspects of immune regulation in the lung has been increasingly recognized. AECII have been shown to participate in cytokine production in inflamed airways and to even act as antigen-presenting cells in both infection and T-cell mediated autoimmunity 1-8. Therefore, they are especially interesting also in clinical contexts such as airway hyper-reactivity to foreign and self-antigens as well as infections that directly or indirectly target AECII. However, our understanding of the detailed immunologic functions served by alveolar type II epithelial cells in the healthy lung as well as in inflammation remains fragmentary. Many studies regarding AECII function are performed using mouse or human alveolar epithelial cell lines 9-12. Working with cell lines certainly offers a range of benefits, such as the availability of large numbers of cells for extensive analyses. However, we believe the use of primary murine AECII allows a better understanding of the role of this cell type in complex processes like infection or autoimmune inflammation. Primary murine AECII can be isolated directly from animals suffering from such respiratory conditions, meaning they have been subject to all additional extrinsic factors playing a role in the analyzed setting. As an example, viable AECII can be isolated from mice intranasally infected with influenza A virus, which primarily targets these cells for replication 13. Importantly, through ex vivo infection of AECII isolated from healthy mice, studies of the cellular responses mounted upon infection can be further extended.
Our protocol for the isolation of primary murine AECII is based on enzymatic digestion of the mouse lung followed by labeling of the resulting cell suspension with antibodies specific for CD11c, CD11b, F4/80, CD19, CD45 and CD16/CD32. Granular AECII are then identified as the unlabeled and sideward scatter high (SSChigh) cell population and are separated by fluorescence activated cell sorting 3.
In comparison to alternative methods of isolating primary epithelial cells from mouse lungs, our protocol for flow cytometric isolation of AECII by negative selection yields untouched, highly viable and pure AECII in relatively short time. Additionally, and in contrast to conventional methods of isolation by panning and depletion of lymphocytes via binding of antibody-coupled magnetic beads 14, 15, flow cytometric cell-sorting allows discrimination by means of cell size and granularity. Given that instrumentation for flow cytometric cell sorting is available, the described procedure can be applied at relatively low costs. Next to standard antibodies and enzymes for lung disintegration, no additional reagents such as magnetic beads are required. The isolated cells are suitable for a wide range of functional and molecular studies, which include in vitro culture and T-cell stimulation assays as well as transcriptome, proteome or secretome analyses 3, 4.

We describe the rapid isolation of primary murine type II alveolar epithelial cells (AECII) by flow cytometric negative selection. These AECII show high viability and purity and are suitable for a wide range of functional and molecular studies regarding their role in respiratory conditions such as autoimmune or infectious diseases.

機能と分子生物学的研究のためのプライマリマウスII型肺胞上皮細胞のフローサイトメトリ分離

Throughout  the last years, the contribution of alveolar type II epithelial cells (AECII)  to various aspects of immune regulation in the lung has been ...

An Experimental Model to Study Tuberculosis-Malaria Coinfection upon Natural Transmission of Mycobacterium tuberculosis and Plasmodium berghei

Coinfections naturally occur due to the geographic overlap of distinct types of pathogenic organisms. Concurrent infections most likely modulate the respective immune response to each single pathogen and may thereby affect pathogenesis and disease outcome. Coinfected patients may also respond differentially to anti-infective interventions. Coinfection between tuberculosis as caused by mycobacteria and the malaria parasite Plasmodium, both of which are coendemic in many parts of sub-Saharan Africa, has not been studied in detail. In order to approach the challenging but scientifically and clinically highly relevant question how malaria-tuberculosis coinfection modulate host immunity and the course of each disease, we established an experimental mouse model that allows us to dissect the elicited immune responses to both pathogens in the coinfected host. Of note, in order to most precisely mimic naturally acquired human infections, we perform experimental infections of mice with both pathogens by their natural routes of infection, i.e. aerosol and mosquito bite, respectively.

An Experimental Model to Study Tuberculosis-Malaria Coinfection upon Natural Transmission of Mycobacterium tuberculosis and Plasmodium berghei

Tuberculosis and malaria are two of the most prevalent infections in humans and major causes of morbidity and mortality in impoverished populations in the tropics. We established an experimental model system to study outcome of malaria-tuberculosis coinfection in mice after challenge with both pathogens via their natural route of infection.

自然送信時に結核マラリア重複感染を研究する実験モデル結核菌とマラリアベルゲイ</i

Coinfections naturally occur due to the geographic overlap of distinct types of pathogenic organisms. Concurrent infections most likely modulate the ...

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource environments. An amplification microarray combines asymmetric PCR amplification, target size selection, target labeling, and microarray hybridization within a single solution and into a single microfluidic chamber. A batch processing method is demonstrated with a 9-plex asymmetric master mix and low-density gel element microarray for genotyping multi-drug resistant Mycobacterium tuberculosis (MDR-TB). The protocol described here can be completed in 6 hr and provide correct genotyping with at least 1,000 cell equivalents of genomic DNA. Incorporating on-chip wash steps is feasible, which will result in an entirely closed amplicon method and system. The extent of multiplexing with an amplification microarray is ultimately constrained by the number of primer pairs that can be combined into a single master mix and still achieve desired sensitivity and specificity performance metrics, rather than the number of probes that are immobilized on the array. Likewise, the total analysis time can be shortened or lengthened depending on the specific intended use, research question, and desired limits of detection. Nevertheless, the general approach significantly streamlines microarray workflow for the end user by reducing the number of manually intensive and time-consuming processing steps, and provides a simplified biochemical and microfluidic path for translating microarray-based diagnostics into routine clinical practice.

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

An amplification microarray combines asymmetric PCR amplification and microarray hybridization into a single chamber, which significantly streamlines microarray workflow for the end user. Simplifying microarray workflow is a necessary first step for creating microarray-based diagnostics that can be routinely used in lower-resource environments.

多剤耐性を実証<em&gt;結核菌</em&gt;増幅マイクロアレイ

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource ...

A Novel Microdissection Approach to Recovering Mycobacterium tuberculosis Specific Transcripts from Formalin Fixed Paraffin Embedded Lung Granulomas

Microdissection has been used for the examination of tissues at DNA, RNA, and protein levels for over a decade. Laser capture microscopy (LCM) is the most common microdissection technique used today. In this technique, a laser is used to focally melt a thermoplastic membrane that overlies a dehydrated tissue section1. The tissue section composite is then lifted and separated from the membrane. Although this technique can be used successfully for tissue examination, it is time consuming and expensive. Furthermore, the successful completion of procedures using this technique requires the use of a laser, thus limiting its use. A new more affordable and practical microdissection approach called mesodissection is a possible solution to the pitfalls of LCM. This technique employs the MESO-1/MeSectr system to mill the desired tissue from a slide mounted tissue sample while concurrently dispensing and aspirating fluid to recover the desired tissue sample into a consumable mill bit. Before the dissection process begins, the user aligns the formalin fixed paraffin embedded (FFPE) slide with a hematoxylin and eosin stained (H&#38;E) reference slide. Thereafter, the operator annotates the desired dissection area and proceeds to dissect the appropriate segment. The program generates an archived image of the dissection. The main advantage of mesodissection is the short duration needed to dissect a slide, taking an average of ten minutes from set up to sample generation in this experiment. Additionally, the system is significantly more cost effective and user friendly. A slight disadvantage is that it is not as precise as laser capture microscopy. In this article we demonstrate how mesodissection can be used to extract RNA from slides from FFPE granulomas caused by Mycobacterium tuberculosis (Mtb).

A Novel Microdissection Approach to Recovering Mycobacterium tuberculosis Specific Transcripts from Formalin Fixed Paraffin Embedded Lung Granulomas

Microdissection has been extensively employed for the examination of DNA, RNA, and protein within tissue. Laser capture microscopy (LCM) is the most commonly used method, but a new milling technique, mesodissection, is recently available. We demonstrate RNA extraction from mesodissected formalin fixed paraffin embedded tissue slides of Mycobacterium tuberculosis granulomas.

回復への新規マイクロダイセクションアプローチ<em&gt;結核菌</em肺肉芽腫、ホルマリン固定パラフィン包埋から&gt;特異的転写

Microdissection has been used for the examination of tissues at DNA, RNA, and protein levels for over a decade. Laser capture microscopy (LCM) is the most ...

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 ...

Analysis of 18FDG PET/CT Imaging as a Tool for Studying Mycobacterium tuberculosis Infection and Treatment in Non-human Primates

Mycobacterium tuberculosis remains the number one infectious agent in the world today. With the emergence of antibiotic resistant strains, new clinically relevant methods are needed that evaluate the disease process and screen for potential antibiotic and vaccine treatments. Positron Emission Tomography/Computed Tomography (PET/CT) has been established as a valuable tool for studying a number of afflictions such as cancer, Alzheimer&#39;s disease, and inflammation/infection. Outlined here are a number of strategies that have been employed to evaluate PET/CT images in cynomolgus macaques that are infected intrabronchially with low doses of M. tuberculosis. Through evaluation of lesion size on CT and uptake of 18F-fluorodeoxyglucose (FDG) in lesions and lymph nodes in PET images, these described methods show that PET/CT imaging can predict future development of active versus latent disease and the propensity for reactivation from a latent state of infection. Additionally, by analyzing the overall level of lung inflammation, these methods determine antibiotic efficacy of drugs against M. tuberculosis in the most clinically relevant existing animal model. These image analysis methods are some of the most powerful tools in the arsenal against this disease as not only can they evaluate a number of characteristics of infection and drug treatment, but they are also directly translatable to a clinical setting for use in human studies.

Analysis of 18FDG PET/CT Imaging as a Tool for Studying Mycobacterium tuberculosis Infection and Treatment in Non-human Primates

Here, we present a protocol to describe the analysis of 18F-FDG PET/CT imaging in non-human primates that have been infected with M. tuberculosis to study disease process, drug treatment, and disease reactivation.

18FDG PET/CT イメージング勉強結核感染と非ひと霊長類における治療のためのツールとしての解析

Mycobacterium tuberculosis remains the number one infectious agent in the world today. With the emergence of antibiotic resistant strains, new clinically ...

Imaging Mycobacterium tuberculosis in Mice with Reporter Enzyme Fluorescence

Reporter enzyme fluorescence (REF) utilizes substrates that are specific for enzymes present in target organisms of interest for imaging or detection by fluorescence or bioluminescence. We utilize BlaC, an enzyme expressed constitutively by all M. tuberculosis strains. REF allows rapid quantification of bacteria in lungs of infected mice. The same group of mice can be imaged at many time points, greatly reducing costs, enumerating bacteria more quickly, allowing novel observations in host-pathogen interactions, and increasing statistical power, since more animals per group are readily maintained. REF is extremely sensitive due to the catalytic nature of the BlaC enzymatic reporter and specific due to the custom flourescence resonance energy transfer (FRET) or fluorogenic substrates used. REF does not require recombinant strains, ensuring normal host-pathogen interactions. We describe the imaging of M. tuberculosis infection using a FRET substrate with maximal emission at 800 nm. The wavelength of the substrate allows sensitive deep tissue imaging in mammals. We will outline aerosol infection of mice with M. tuberculosis, anesthesia of mice, administration of the REF substrate, and optical imaging. This method has been successfully applied to evaluating host-pathogen interactions and efficacy of antibiotics targeting M. tuberculosis.

Imaging Mycobacterium tuberculosis in Mice with Reporter Enzyme Fluorescence

We describe the optical imaging of mice infected with Mycobacterium tuberculosis (M. tuberculosis) using reporter enzyme fluorescence (REF). This protocol facilitates the sensitive and specific detection of M. tuberculosis in pre-clinical animal models for pathogenesis, therapeutics and vaccine research.

レポーター酵素蛍光を用いたマウスにおける結核菌をイメージング

Reporter enzyme fluorescence (REF) utilizes substrates that are specific for enzymes present in target organisms of interest for imaging or detection by ...

Modeling Tuberculosis in Mycobacterium marinum Infected Adult Zebrafish

Mycobacterium tuberculosis is currently the deadliest human pathogen causing 1.7 million deaths and 10.4 million infections every year. Exposure to this bacterium causes a wide disease spectrum in humans ranging from a sterilized infection to an actively progressing deadly disease. The most common form is the latent tuberculosis, which is asymptomatic, but has the potential to reactivate into a fulminant disease. Adult zebrafish and its natural pathogen Mycobacterium marinum have recently proven to be an applicable model to study the wide disease spectrum of tuberculosis. Importantly, spontaneous latency and reactivation as well as adaptive immune responses in the context of mycobacterial infection can be studied in this model. In this article, we describe methods for the experimental infection of adult zebrafish, the collection of internal organs for the extraction of nucleic acids for the measurement of mycobacterial loads and host immune responses by quantitative PCR. The in-house-developed, M. marinum-specific qPCR assay is more sensitive than the traditional plating methods as it also detects DNA from non-dividing, dormant or recently dead mycobacteria. As both DNA and RNA are extracted from the same individual, it is possible to study the relationships between the diseased state, and the host and pathogen gene-expression. The adult zebrafish model for tuberculosis thus presents itself as a highly applicable, non-mammalian in vivo system to study host-pathogen interactions.

Modeling Tuberculosis in Mycobacterium marinum Infected Adult Zebrafish

Here, we present a protocol to model human tuberculosis in an adult zebrafish using its natural pathogen Mycobacterium marinum. Extracted DNA and RNA from the internal organs of infected zebrafish can be used to reveal the total mycobacterial loads in the fish and the host&#39;s immune responses with qPCR.

結核抗酸菌 marinum感染成人ゼブラフィッシュをモデル化

Mycobacterium tuberculosis is currently the deadliest human pathogen causing 1.7 million deaths and 10.4 million infections every year. Exposure to this ...