作者想感谢所有欧洲投资银行的成员，为开发这一技术。这项研究得到了部分科研优先领域"交通膜"（议员）和感染现象"黑客帝国"（KH），青年科学家（SF和KH），科研（何的格兰特在援助）和"细胞内物流"（何）从教育部，文化，体育，科学和技术日本，创新领域的科学研究。

1。细菌细胞的制备<ol><li>摆放着数甘油荧光的细菌（如绿色荧光蛋白表达的鼠伤寒沙门氏菌）的LB琼脂平板，含100μg / ml的氨苄青霉素。 </li><li>文化从单菌落LB琼脂2毫升的新的LB培养基中过夜。 </li><li>添加0.5毫升细菌培养，直到在600 nm的光密度达到1.0至4.5毫升的新的LB培养基孵育。 </li><li>收获的细菌细胞，离心（3000 XG，5分钟，4℃）。 </li><li>弃上清，5.0毫升的无菌磷酸盐缓冲液（PBS）洗两次。 </li><li> 5毫升的PBS重悬菌体，并用50μL暂停接种含有约10 7菌落形成单位（CFU） 。 </li><li>在使用荧光标记的细菌的情况下，细菌细胞标记的荧光标记试剂，根据标准协议。 </li></ol> 2。一nesthesia <ol><li> 5％（V / V）填充一个小塑料盒（10 × 10 × 5厘米），蒸发异氟醚（流量:200毫升/分钟）与空气混合。 </li><li>麻醉八个弱十六岁的男性或女性在框中小鼠。 </li><li>麻醉后，将小鼠进行尸检表。 </li><li>不断麻醉2％（V / V）的小鼠异氟醚蒸发与空气混合（流量:200毫升/分钟）（ 图1）。这是一个终端程序。 </li></ol> 3。结扎Peyer氏补丁循环检测<ol><li>腹部皮肤，然后切开1厘米削减麻醉小鼠的腹腔腹膜，取出小肠Peyer氏补丁。 </li><li>结扎肠道缝纫纱，照顾，以避免血管。注:只能绑定一个侧面的肠道，并留下对方松动。 </li><li>宽松的小号50μL菌悬液或PBS（对照组）用注射器注入结扎Peyer氏补丁循环肠道IDE（ 图2）。 </li><li>绑定宽松的一面，并关闭鼠标的腹部剪辑。 </li><li> 1小时后，取出结扎Peyer氏补丁循环，安乐死颈椎脱位鼠标。 </li><li>海关Peyer氏补丁结扎Peyer氏补丁循环。 </li><li>闪烁的PBS1毫升Peyer氏补丁根尖使用注射器针，去除多余的粘膜液体和细菌。一个额外的两次闪烁Peyer氏补丁。 </li></ol> 4。 Peyer氏补丁整装染色和激光共聚焦显微镜分析<ol><li> Peyer氏补丁修复BD Cytofix / Cytoperm冰1小时解决方案。 </li><li>屋宇署权限/洗5分钟缓冲1毫升Peyer氏补丁洗净三次和然后块1毫升阻止包含0.1％（W / V）皂甙，0.2％（W ​​/ V）BSA的PBS 30分钟就缓冲冰。 </li><li>加入200倍稀释的抗鼠GP2的单克隆抗体（5微克/毫升）标本检测M细胞。 </li><li>在室温下2小时或过夜孵育4 ° C。 </li><li> 1毫升冷PBS洗三次，再加入200倍稀释的抗鼠IgG抗体DyLight549（20微克/毫升）的标本共轭。 </li><li>孵育2小时的冰样本。 </li><li> 1毫升冷PBS洗三次，然后加入50倍稀释Alexa的633标记的鬼笔环肽标本检测F -肌动蛋白。 </li><li>在冰上孵育2小时。 </li><li> 1毫升冷PBS轻轻冲洗。然后放置在三到四个圆形玻璃盖片，幻灯片和嵌入的标本中30％的甘油PBS溶液幻灯片上（ 图3）。 </li><li>一个DM - IRE2共聚焦激光扫描显微镜或DeltaVision恢复反卷积显微镜观察标本。 </li></ol> 5。代表性的成果: 鼠标的标本例如结扎Peyer氏修补与绿色荧光蛋白伤寒的循环实验murium观察与DeltaVision恢复反卷积显微镜（ 图4）。 GFP的鼠伤寒沙门氏菌是transcytosed由GP2 + M细胞。可以由M细胞transcytosed的小鼠Peyer氏修补肠袢检测可以识别的一种共生或致病菌。 <img alt="图1" src="/files/ftp_upload/3225/3225fig1.jpg" /> 图1。蒸发异氟醚条件下小鼠的麻醉。汽化异氟醚麻醉专用器具（左侧）提供。 <img alt="图2" src="/files/ftp_upload/3225/3225fig2.jpg" /> 图2。结扎Peyer氏修补肠袢实验总结。荧光菌悬液通过注射器注入肠道松边结扎Peyer氏补丁循环。 <img alt="图3" src="/files/ftp_upload/3225/3225fig3.jpg" /> <s聪&gt;图3。安装的标本。嵌入式标本中30％的甘油在PBS溶液中，在一个特殊的幻灯片，在其中一个穿孔的塑料板（1mm厚）粘合剂载玻片上的约束。 <img alt="图4" src="/files/ftp_upload/3225/3225fig4.jpg" /> 图4。结扎Peyer氏修补与GFP的鼠伤寒沙门氏菌循环实验鼠标的例子。 GP2的，这是M细胞特异性标志物5报道，染色试样抗鼠GP2的抗体（红色）。与DeltaVision恢复反卷积显微镜观察。 GFP的表达鼠伤寒沙门氏菌是共同本地化与GP2的M细胞的顶质膜和subapical细胞质囊泡（箭头） 。顶，根尖的看法。底部和侧面，外侧意见。比例尺:10微米。

<ol>
	<li>Fagarasan, S., Honjo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intestinal+IgA+synthesis:+regulation+of+front-line+body+defences.">Intestinal IgA synthesis: regulation of front-line body defences.</a> Nat. Rev. Immunol. 3, 63-72 (2003).</li><li>Hapfelmeier, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversible+microbial+colonization+of+germ-free+mice+reveals+the+dynamics+of+IgA+immune+responses.">Reversible microbial colonization of germ-free mice reveals the dynamics of IgA immune responses.</a> Science. 328, 1705-1709 (2010).</li><li>Owen, R. L., Jones, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+cell+specialization+within+human+Peyer's+patches:+an+ultrastructural+study+of+intestinal+lymphoid+follicles.">Epithelial cell specialization within human Peyer's patches: an ultrastructural study of intestinal lymphoid follicles.</a> Gastroenterology. 66, 189-203 (1974).</li><li>Neutra, M. R., Mantis, N. J., Kraehenbuhl, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collaboration+of+epithelial+cells+with+organized+mucosal+lymphoid+tissues.">Collaboration of epithelial cells with organized mucosal lymphoid tissues.</a> Nat. Immunol. 2, 1004-1009 (2001).</li><li>Hase, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uptake+through+glycoprotein+2+of+FimH(+)+bacteria+by+M+cells+initiates+mucosal+immune+response.">Uptake through glycoprotein 2 of FimH(+) bacteria by M cells initiates mucosal immune response.</a> Nature. 462, 226-230 (2009).</li><li>Punyashthiti, K., Finkelstein, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enteropathogenicity+of+Escherichia+coli.+I.+Evaluation+of+mouse+intestinal+loops.">Enteropathogenicity of Escherichia coli. I. Evaluation of mouse intestinal loops.</a> Infect. Immun. 4, 473-478 (1971).</li><li>Owen, R. L., Pierce, N. F., Apple, R. T., Cray, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=M+cell+transport+of+Vibrio+cholerae+from+the+intestinal+lumen+into+Peyer's+patches:+a+mechanism+for+antigen+sampling+and+for+microbial+transepithelial+migration.">M cell transport of Vibrio cholerae from the intestinal lumen into Peyer's patches: a mechanism for antigen sampling and for microbial transepithelial migration.</a> J. Infect. Dis. 153, 1108-1118 (1986).</li><li>Owen, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=M+cells--entryways+of+opportunity+for+enteropathogens.">M cells--entryways of opportunity for enteropathogens.</a> J. Exp. Med. 180, 7-9 (1994).</li><li>Clark, M. A., Hirst, B. H., Jepson, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=M-cell+surface+beta1+integrin+expression+and+invasin-mediated+targeting+of+Yersinia+pseudotuberculosis+to+mouse+Peyer's+patch+M+cells.">M-cell surface beta1 integrin expression and invasin-mediated targeting of Yersinia pseudotuberculosis to mouse Peyer's patch M cells.</a> Infect. Immun. 66, 1237-1243 (1998).</li><li>Jensen, V. B., Harty, J. T., Jones, B. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interactions+of+the+invasive+pathogens+Salmonella+typhimurium,+Listeria+monocytogenes,+and+Shigella+flexneri+with+M+cells+and+murine+Peyer's+patches.">Interactions of the invasive pathogens Salmonella typhimurium, Listeria monocytogenes, and Shigella flexneri with M cells and murine Peyer's patches.</a> Infect. Immun. 66, 3758-3766 (1998).</li><li>Nagai, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+Peyer's+patches+in+the+induction+of+Helicobacter+pylori-induced+gastritis.">Role of Peyer's patches in the induction of Helicobacter pylori-induced gastritis.</a> Proc. Natl. Acad. Sci. U. S. A. 104, 8971-8976 (2007).</li></ol>

没有利益冲突的声明。

<html>结扎Peyer氏菌悬液的补丁的孵化时间通常为1小时观察到M细胞的细菌掺入。在4小时孵化的情况下，细菌往往检测Peyer氏斑的T细胞区。由于蒸发异氟醚吸入麻醉小鼠保持稳定，结扎Peyer氏菌悬液的补丁的孵化时间可延长至观察T细胞Peyer氏补丁区移动的细菌。这个实验的重要的一点是要小心，不要划伤血管结扎肠道时。在不使用GFP表达的细菌的情况下，我们也可以选择使用商业荧光标记试剂荧光标...

<table border="1"><tbody><tr><th>试剂名称</th><th>公司</th><th>目录编号</th><th>评论（可选） </th></tr><tr><td> LB琼脂氨苄青霉素 100 </td><td>西格玛</td><td> L5667 </td><td></td></tr><tr><td> Cy3标记单反应 染料包</td><td> GE医疗集团</td><td> PA23001 </td><td></td></tr><tr><td>的Alexa Fluor 350 羧酸， 琥珀酰亚胺酯</td><td> Invitrogen公司</td><td> A10168 </td><td></td></tr><tr><td>吸入麻醉 仪器</td><td>信浓制作所</td><td> SN - 487 </td><td></td></tr><tr><td>固定和 通透 解决方案</td><td>屋宇署</td><td> 554722 </td><td></td></tr><tr><td>抗鼠 糖蛋白2 抗体</td><td> MBL </td><td>D278 - 3 </td><td> 200倍稀释液（5μg/ml） </td></tr><tr><td>羊抗鼠IgG， F（AB&#39;）2片段 具体</td><td>杰克逊 ImmunoResearch </td><td> 112-505-006 </td><td> 200倍稀释液（20μg/ml） </td></tr><tr><td>的Alexa Fluor 633 鬼笔环肽</td><td>分子探针</td><td> A22284 </td><td> 50倍稀释</td></tr><tr><td>激光共聚焦 扫描显微镜</td><td>徕卡显微系统</td><td> DMIRE2 </td><td></td></tr><tr><td> DeltaVision 恢复 反卷积 显微镜</td><td>应用精密</td><td> DeltaVision核心</td><td></td></tr></tbody></table>

application of a mouse ligated peyer&#x2019;s patch intestinal loop assay to evaluate bacterial uptake by m cells

我们的肠道内居住的共生细菌的数量巨大。对胃肠道的黏膜表面不断暴露给他们，并偶尔病原体。肠道相关淋巴组织（GALT）为诱导黏膜免疫反应，这些微生物1，2中发挥了关键作用。要启动黏膜免疫反应，粘膜抗原必须运从肠腔整个组织，如Peyer氏斑淋巴滤泡的上皮屏障。这介导的抗原transcytosis是由专门的上皮M细胞3， 4。 M细胞是非典型的上皮细胞，积极吞噬大分子物质和微生物。 M细胞与树突状细胞（DCs）和巨噬细胞，靶抗原降解的溶酶体，主要transcytose内在抗原。这种积极通过M细胞的大分子transcytosis提供抗原的根本组织淋巴滤泡D是认为启动抗原特异性黏膜免疫反应的关键。然而，促进M细胞抗原摄取的分子机制在很大程度上是未知的。我们曾报道，糖蛋白2（GP2），特别是肠之间的M细胞的根尖质膜上表示，作为一个transcytotic受体的共生和致病肠杆菌的一个子集，包括大肠杆菌和沙门氏菌血清型鼠伤寒沙门氏菌（鼠伤寒沙门氏菌），通过承认FimH，细菌外膜5菌毛类型的组成部分，我。在这里，我们提出了一个鼠标Peyer氏修补肠袢的检测，以评估M细胞的细菌摄取的应用方法。这个方法是鼠标肠袢先前所描述的6，7含量的改进版本。改进的要点如下:1。异氟醚被用作麻醉剂。 2。约1厘米结扎肠循环includING Peyer氏补丁成立。 3。 M细胞的细菌荧光标记的荧光标记试剂或过度表达的荧光蛋白，如绿色荧光蛋白（GFP）。 4。 M细胞相关的卵泡上皮覆盖Peyer氏补丁与反GP2抗体检测整个安装immunostainig。 5。荧光共聚焦显微镜分析观察M细胞的细菌transcytosis。小鼠Peyer氏补丁肠袢实验可以提供答案，什么样的共生或transcytosed M细胞的致病细菌，并可能导致我们了解如何通过M细胞刺激粘膜免疫系统的分子机制。

Watch this Scientific Journal Video about Application of a Mouse Ligated PeyerÃ¢â‚¬â„¢s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells at JoVE.com

Application of a Mouse Ligated Peyer&#8217;s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells

在一个专门的卵泡相关Peyer氏斑上皮M细胞在肠道相关淋巴组织的粘膜免疫监视中发挥的重要作用。在这里，我们描述了细菌transcytosis M细胞的评价方法<em&gt;在体内</em&gt;。这种方法提供了一种方法，以了解在免疫系统中的M -细胞功能。

鼠标应用结扎Peyer氏修补肠袢含量评价M细胞的细菌吸收

The inside of our gut is inhabited with enormous number of commensal bacteria. The mucosal surface of the gastrointestinal tract is continuously exposed ...

application-mouse-ligated-peyers-patch-intestinal-loop-assay-to

Research

JoVE Journal

Immunology and Infection

Application of a Mouse Ligated Peyer&#x2019;s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells

19.4K 次观看.  RIKEN Research Center for Allergy and Immunology. 在一个专门的卵泡相关Peyer氏斑上皮M细胞在肠道相关淋巴组织的粘膜免疫监视中发挥的重要作用。在这里，我们描述了细菌transcytosis M细胞的评价方法在体内。这种方法提供了一种方法，以了解在免疫系统中的M -细胞功能。

视频: Application of a Mouse Ligated Peyer’s Patch Intestinal Loop Assay to Evaluate Bacterial Uptake by M cells

Using Luciferase to Image Bacterial Infections in Mice

Imaging is a valuable technique that can be used to monitor biological processes. In particular, the presence of cancer cells, stem cells, specific immune cell types, viral pathogens, parasites and bacteria can be followed in real-time within living animals 1-2. Application of bioluminescence imaging to the study of pathogens has advantages as compared to conventional strategies for analysis of infections in animal models3-4. Infections can be visualized within individual animals over time, without requiring euthanasia to determine the location and quantity of the pathogen. Optical imaging allows comprehensive examination of all tissues and organs, rather than sampling of sites previously known to be infected. In addition, the accuracy of inoculation into specific tissues can be directly determined prior to carrying forward animals that were unsuccessfully inoculated throughout the entire experiment. Variability between animals can be controlled for, since imaging allows each animal to be followed individually. Imaging has the potential to greatly reduce animal numbers needed because of the ability to obtain data from numerous time points without having to sample tissues to determine pathogen load3-4.
This protocol describes methods to visualize infections in live animals using bioluminescence imaging for recombinant strains of bacteria expressing luciferase. The click beetle (CBRLuc) and firefly luciferases (FFluc) utilize luciferin as a substrate5-6. The light produced by both CBRluc and FFluc has a broad wavelength from 500 nm to 700 nm, making these luciferases excellent reporters for the optical imaging in living animal models7-9. This is primarily because wavelengths of light greater than 600 nm are required to avoid absorption by hemoglobin and, thus, travel through mammalian tissue efficiently. Luciferase is genetically introduced into the bacteria to produce light signal10. Mice are pulmonary inoculated with bioluminescent bacteria intratracheally to allow monitoring of infections in real time. After luciferin injection, images are acquired using the IVIS Imaging System. During imaging, mice are anesthetized with isoflurane using an XGI-8 Gas Anethesia System. Images can be analyzed to localize and quantify the signal source, which represents the bacterial infection site(s) and number, respectively. After imaging, CFU determination is carried out on homogenized tissue to confirm the presence of bacteria. Several doses of bacteria are used to correlate bacterial numbers with luminescence. Imaging can be applied to study of pathogenesis and evaluation of the efficacy of antibacterial compounds and vaccines.

Methods for bioluminescence imaging of bacterial infections in living animals are decribed. Pathogens are modified to express luciferase allowing optical whole body imaging of infections in live animals. Animal models can be infected with luciferase expressing pathogens and the resulting course of disease visualized in real-time by bioluminescence imaging.

用荧光素酶在小鼠细菌性感染的形象

Imaging is a valuable technique that can be used to monitor biological processes.  In particular, the presence of cancer cells, stem cells, specific ...

科研

免疫与感染

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.

由细菌病原体入侵人体细胞

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

A Visual Assay to Monitor T6SS-mediated Bacterial Competition

Type VI secretion systems (T6SSs) are molecular nanomachines allowing Gram-negative bacteria to transport and inject proteins into a wide variety of target cells1,2. The T6SS is composed of 13 core components and displays structural similarities with the tail-tube of bacteriophages3. The phage uses a tube and a puncturing device to penetrate the cell envelope of target bacteria and inject DNA. It is proposed that the T6SS is an inverted bacteriophage device creating a specific path in the bacterial cell envelope to drive effectors and toxins to the surface. The process could be taken further and the T6SS device could perforate other cells with which the bacterium is in contact, thus injecting the effectors into these targets. The tail tube and puncturing device parts of the T6SS are made with Hcp and VgrG proteins, respectively4,5.
The versatility of the T6SS has been demonstrated through studies using various bacterial pathogens. The Vibrio cholerae T6SS can remodel the cytoskeleton of eukaryotic host cells by injecting an "evolved" VgrG carrying a C-terminal actin cross-linking domain6,7. Another striking example was recently documented using Pseudomonas aeruginosa which is able to target and kill bacteria in a T6SS-dependent manner, therefore promoting the establishment of bacteria in specific microbial niches and competitive environment8,9,10.
In the latter case, three T6SS-secreted proteins, namely Tse1, Tse2 and Tse3 have been identified as the toxins injected in the target bacteria (Figure 1). The donor cell is protected from the deleterious effect of these effectors via an anti-toxin mechanism, mediated by the Tsi1, Tsi2 and Tsi3 immunity proteins8,9,10. This antimicrobial activity can be monitored when T6SS-proficient bacteria are co-cultivated on solid surfaces in competition with other bacterial species or with T6SS-inactive bacteria of the same species8,11,12,13.
The data available emphasized a numerical approach to the bacterial competition assay, including time-consuming CFU counting that depends greatly on antibiotic makers. In the case of antibiotic resistant strains like P. aeruginosa, these methods can be inappropriate. Moreover, with the identification of about 200 different T6SS loci in more than 100 bacterial genomes14, a convenient screening tool is highly desirable. We developed an assay that is easy to use and requires standard laboratory material and reagents. The method offers a rapid and qualitative technique to monitor the T6SS-dependent bactericidal/bacteriostasis activity by using a reporter strain as a prey (in this case Escherichia coli DH5&alpha;) allowing a-complementation of the lacZ gene. Overall, this method is graphic and allows rapid identification of T6SS-related phenotypes on agar plates. This experimental protocol may be adapted to other strains or bacterial species taking into account specific conditions such as growth media, temperature or time of contact.

We describe a qualitative assay to monitor bacterial competition mediated by the Pseudomonas aeruginosa type VI secretion system (T6SS). The assay relies on the survival/killing of Escherichia coli target cells carrying a lacZ-reporter. This technique is adjustable to assess the bactericidal/bacteriostasis activity of T6SS-proficient microorganisms.

的视觉检测，以监测T6SS介导的细菌竞争

Type VI secretion systems (T6SSs) are molecular  nanomachines allowing Gram-negative bacteria to transport and inject proteins  into a wide variety of ...

The Mesenteric Lymph Duct Cannulated Rat Model: Application to the Assessment of Intestinal Lymphatic Drug Transport

The intestinal lymphatic system plays key roles in fluid transport, lipid absorption and immune function. Lymph flows directly from the small intestine via a series of lymphatic vessels and nodes that converge at the superior mesenteric lymph duct. Cannulation of the mesenteric lymph duct thus enables the collection of mesenteric lymph flowing from the intestine. Mesenteric lymph consists of a cellular fraction of immune cells (99% lymphocytes), aqueous fraction (fluid, peptides and proteins such as cytokines and gut hormones) and lipoprotein fraction (lipids, lipophilic molecules and apo-proteins). The mesenteric lymph duct cannulation model can therefore be used to measure the concentration and rate of transport of a range of factors from the intestine via the lymphatic system. Changes to these factors in response to different challenges (e.g., diets, antigens, drugs) and in disease (e.g., inflammatory bowel disease, HIV, diabetes) can also be determined. An area of expanding interest is the role of lymphatic transport in the absorption of orally administered lipophilic drugs and prodrugs that associate with intestinal lipid absorption pathways. Here we describe, in detail, a mesenteric lymph duct cannulated rat model which enables evaluation of the rate and extent of lipid and drug transport via the lymphatic system for several hours following intestinal delivery. The method is easily adaptable to the measurement of other parameters in lymph. We provide detailed descriptions of the difficulties that may be encountered when establishing this complex surgical method, as well as representative data from failed and successful experiments to provide instruction on how to confirm experimental success and interpret the data obtained.

Here we describe a technique to cannulate the mesenteric lymph duct in rats which enables quantification of lipid and drug transport via the lymphatic system following intestinal delivery. The technique can be adapted to assess mesenteric lymph concentrations and/or transport of fluid, immune cells, peptides, proteins and lipophilic molecules.

在肠系膜淋巴管空心​​大鼠模型:应用肠淋巴药物运输的评估

The intestinal lymphatic system plays key roles in fluid transport, lipid absorption and immune function. Lymph flows directly from the small intestine ...

Application of Long-term cultured Interferon-&#947; Enzyme-linked Immunospot Assay for Assessing Effector and Memory T Cell Responses in Cattle

Effector and memory T cells are generated through developmental programing of na&#239;ve cells following antigen recognition. If the infection is controlled up to 95 % of the T cells generated during the expansion phase are eliminated (i.e., contraction phase) and memory T cells remain, sometimes for a lifetime. In humans, two functionally distinct subsets of memory T cells have been described based on the expression of lymph node homing receptors. Central memory T cells express C-C chemokine receptor 7 and CD45RO and are mainly located in T-cell areas of secondary lymphoid organs. Effector memory T cells express CD45RO, lack CCR7 and display receptors associated with lymphocyte homing to peripheral or inflamed tissues. Effector T cells do not express either CCR7 or CD45RO but upon encounter with antigen produce effector cytokines, such as interferon-&#947;. Interferon-&#947; release assays are used for the diagnosis of bovine and human tuberculosis and detect primarily effector and effector memory T cell responses. Central memory T cell responses by CD4+ T cells to vaccination, on the other hand, may be used to predict vaccine efficacy, as demonstrated with simian immunodeficiency virus infection of non-human primates, tuberculosis in mice, and malaria in humans. Several studies with mice and humans as well as unpublished data on cattle, have demonstrated that interferon-&#947; ELISPOT assays measure central memory T cell responses. With this assay, peripheral blood mononuclear cells are cultured in decreasing concentration of antigen for 10 to 14 days (long-term culture), allowing effector responses to peak and wane; facilitating central memory T cells to differentiate and expand within the culture.

Long-term cultured interferon-&#947; enzyme-linked immunospot assay is used as a measure of central memory responses and correlates with protective anti-mycobacterial vaccine responses. With this assay, peripheral blood mononuclear cells are stimulated with mycobacterial antigens and interleukin-2 for 14 days, enabling differentiation and expansion of central memory T cells.

长期培养的干扰素γ酶联免疫检测方法的评估效应和记忆T细胞应答的牛应用

Effector and memory T cells are generated through developmental programing of na&#239;ve cells following antigen recognition. If the infection is ...

Detecting Cortex Fragments During Bacterial Spore Germination

The process of endospore germination in Clostridium difficile, and other Clostridia, increasingly is being found to differ from the model spore-forming bacterium, Bacillus subtilis. Germination is triggered by small molecule germinants and occurs without the need for macromolecular synthesis. Though differences exist between the mechanisms of spore germination in species of Bacillus and Clostridium, a common requirement is the hydrolysis of the peptidoglycan-like cortex which allows the spore core to swell and rehydrate. After rehydration, metabolism can begin and this, eventually, leads to outgrowth of a vegetative cell. The detection of hydrolyzed cortex fragments during spore germination can be difficult and the modifications to the previously described assays can be confusing or difficult to reproduce. Thus, based on our recent report using this assay, we detail a step-by-step protocol for the colorimetric detection of cortex fragments during bacterial spore germination.

Herein, we describe a colorimetric assay to detect the presence of reducing sugars during bacterial spore germination.

检测皮质片段在细菌孢子萌发

The process of endospore germination in Clostridium difficile, and other Clostridia, increasingly is being found to differ from the model spore-forming ...

Use of a Monocyte Monolayer Assay to Evaluate Fc&#947; Receptor-mediated Phagocytosis

Although originally developed for predicting transfusion outcomes of serologically incompatible blood, the monocyte monolayer assay (MMA) is a highly versatile in vitro assay that can be modified to examine different aspects of antibody and Fc&#947; receptor (Fc&#947;R)-mediated phagocytosis in both research and clinical settings. The assay utilizes adherent monocytes from peripheral blood mononuclear cells isolated from mammalian whole blood. MMA has been described for use in both human and murine investigations. These monocytes express Fc&#947;Rs (e.g., Fc&#947;RI, Fc&#947;RIIA, Fc&#947;RIIB, and Fc&#947;RIIIA) that are involved in immune responses. The MMA exploits the mechanism of Fc&#947;R-mediated interactions, phagocytosis in particular, where antibody-sensitized red blood cells (RBCs) adhere to and/or activate Fc&#947;Rs and are subsequently phagocytosed by the monocytes. In vivo, primarily tissue macrophages found in the spleen and liver carry out Fc&#947;R-mediated phagocytosis of antibody-opsonized RBCs, causing extravascular hemolysis. By evaluating the level of phagocytosis using the MMA, different aspects of the in vivo Fc&#947;R-mediated process can be investigated. Some applications of the MMA include predicting the clinical relevance of allo- or autoantibodies in a transfusion setting, assessing candidate drugs that promote or inhibit phagocytosis, and combining the assay with fluorescent microscopy or traditional Western immunoblotting to investigate the downstream signaling effects of Fc&#947;R-engaging drugs or antibodies. Some limitations include the laboriousness of this technique, which takes a full day from start to finish, and the requirement of research ethics approval in order to work with mammalian blood. However, with diligence and adequate training, the MMA results can be obtained within a 24-h turnover time.

The monocyte monolayer assay (MMA) is an in vitro assay that utilizes isolated primary monocytes obtained from mammalian peripheral whole blood to evaluate Fc&#947; receptor (Fc&#947;R)-mediated phagocytosis.

单核细胞单层试验中用于评估Fcγ受体介导的吞噬作用

Although originally developed for predicting transfusion outcomes of serologically incompatible blood, the monocyte monolayer assay (MMA) is a highly ...

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

Fluorescent imaging of cellular components is an effective tool to investigate host-pathogen interactions. Pathogens can affect many different features of infected cells, including organelle ultrastructure, cytoskeletal network organization, as well as cellular processes such as Stress Granule (SG) formation. The characterization of how pathogens subvert host processes is an important and integral part of the field of pathogenesis. While variable phenotypes may be readily visible, the precise analysis of the qualitative and quantitative differences in the cellular structures induced by pathogen challenge is essential for defining statistically significant differences between experimental and control samples. SG formation is an evolutionarily conserved stress response that leads to antiviral responses and has long been investigated using viral infections1. SG formation also affects signaling cascades and may have other still unknown consequences2. The characterization of this stress response to pathogens other than viruses, such as bacterial pathogens, is currently an emerging area of research3. For now, quantitative and qualitative analysis of SG formation is not yet routinely used, even in the viral systems. Here we describe a simple method for inducing and characterizing SG formation in uninfected cells and in cells infected with a cytosolic bacterial pathogen, which affects the formation of SGs in response to various exogenous stresses. Analysis of SG formation and composition is achieved by using a number of different SG markers and the spot detector plug-in of ICY, an open source image analysis tool.

We describe a method for the qualitative and quantitative analysis of stress granule formation in mammalian cells after the cells are challenged with bacteria and a number of different stresses. This protocol can be applied to investigate the cellular stress granule response in a wide range of host-bacterial interactions.

哺乳动物细胞细菌挑战后应激颗粒形成的免疫荧光分析

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

A Novel In Vitro Wound Healing Assay to Evaluate Cell Migration

The aim of this work is to show a novel method to evaluate the ability of some immunomodulatory molecules, such as antimicrobial peptides (AMPs), to stimulate cell migration. Importantly, cell migration is a rate-limiting event during the wound-healing process to re-establish the integrity and normal function of tissue layers after injury. The advantage of this method over the classical assay, which is based on a manually made scratch in a cell monolayer, is the usage of special silicone culture inserts providing two compartments to create a cell-free pseudo-wound field with a well-defined width (500 &#956;m). In addition, due to an automated image analysis platform, it is possible to rapidly obtain quantitative data on the speed of wound closure and cell migration. More precisely, the effect of two frog-skin AMPs on the migration of bronchial epithelial cells will be shown. Furthermore, pretreatment of these cells with specific inhibitors will provide information on the molecular mechanisms underlying such events.

A Novel In Vitro Wound Healing Assay to Evaluate Cell Migration

Here, we present a protocol to evaluate the effect of peptides on the migration of bronchial epithelial cells. This method allows for the rapid and highly reproducible obtainment of quantitative data on the speed of cell migration and wound closure.

一种新的体外创面愈合试验评价细胞迁移

The aim of this work is to show a novel method to evaluate the ability of some immunomodulatory molecules, such as antimicrobial peptides (AMPs), to ...

Cell Membrane Repair Assay Using a Two-photon Laser Microscope

Numerous pathophysiological insults can cause damage to cell membranes and, when coupled with innate defects in cell membrane repair or integrity, can result in disease. Understanding the underlying molecular mechanisms surrounding cell membrane repair is, therefore, an important objective to the development of novel therapeutic strategies for diseases associated with dysfunctional cell membrane dynamics. Many in vitro and in vivo studies aimed at understanding cell membrane resealing in various disease contexts utilize two-photon laser ablation as a standard for determining functional outcomes following experimental treatments. In this assay, cell membranes are subjected to wounding with a two-photon laser, which causes the cell membrane to rupture and fluorescent dye to infiltrate the cell. The intensity of fluorescence within the cell can then be monitored to quantify the cell's ability to reseal itself. There are several alternative methods for assessing cell membrane response to injury, as well as great variation in the two-photon laser wounding approach itself, therefore, a single, unified model of cell wounding would beneficially serve to decrease the variation between these methodologies. In this article, we outline a simple two-photon laser wounding protocol for assessing cell membrane repair in vitro in both healthy and dysferlinopathy patient fibroblast cells transfected with or without a full-length dysferlin plasmid.

Cell membrane wounding via two-photon laser is a widely used method for assessing membrane resealing ability and can be applied to multiple cell types. Here, we describe a protocol for in vitro live-imaging of membrane resealing in dysferlinopathy patient cells following two-photon laser ablation.

双光子激光显微镜在细胞膜修复中的应用

Numerous pathophysiological insults can cause damage to cell membranes and, when coupled with innate defects in cell membrane repair or integrity, can ...