The authors gratefully acknowledge Drs James Roth, William Nauseef and Kayoko Kimura and Mr Tom Skadow for assistance with development of the canine neutrophil protocols. RDG is supported by a Wellcome Trust Fellowship ref: WT093767MA.

所有实验均来自爱荷华州立大学机构动物护理和使用委员会批准伦理进行。 1.采血车<ol><li>绘制的9ml血从隐，头或颈静脉直接进入抗凝剂（ 例如，乙二胺四乙酸（EDTA），1.8毫克的 K 2 EDTA /毫升血）真空采血管，或与直接传送到含有EDTA的血液管的注射器。轻轻摇动或反转血管，以确保血液和抗凝血剂的充分混合。 </li></ol> 2.中性粒细胞隔离<ol><li>在50ml锥形管中，用等体积的无菌室温度的混合血3％葡聚糖-500（0.9％无菌盐水组成）轻轻翻转。留在室温下直立18-20分钟。的稻草色上层转移到一个新的试管，直至其不再能够不污染由下红色层收集。在日红细胞Ë原管可被丢弃。 </li><li>离心上清在500 xg离心在4℃下10分钟。抽出并丢弃上清液。手动重新悬浮在10毫升室温的无菌磷酸盐缓冲盐水（PBS）细胞沉淀。注意，涡旋不应该被用来在这个协议中的任何阶段重新悬浮中性粒细胞。手工绘制关闭，而不是浇灭上清还建议在整个协议以最大限度地提高细胞产量。 </li><li> 10毫升室温多聚蔗糖和泛影酸钠细胞分离溶液（ 例如 ，的Histopaque 1077）添加到50毫升锥形管中。小心层在细胞分离溶液中的含细胞溶液。注意这并没有平衡到室温可减少细胞产量，使用细胞分离溶液。 </li><li>离心在300×g离心在室温下与制动切断30分钟。 </li><li>嗜中性粒细胞是在梯度的最低层，抽出并丢弃UPPER 3层，血浆和血小板，单核细胞的窄的白色带和密度梯度介质的透明层的上层的构成。 </li><li>以溶解任何残留的红细胞，再悬浮在10毫升室温的水中的嗜中性粒细胞颗粒。 </li><li> 30秒后，通过加入10ml的无菌室温1.8％氯化钠恢复张力和轻轻地倒转混合。 </li><li>离心机在500×g离心在4℃下5分钟。抽出上清液并丢弃。 </li><li>如果丸粒仍然是红色，重复裂解步骤。如果颗粒是白色的（或者如果裂解已经执行两次），轻轻地在10ml无菌PBS重新悬浮细胞。 </li><li>计数使用自动计数器或血球细胞。典型产量是每毫升血液中的至少10 6个细胞。 </li><li>离心机在500×g离心在4℃下5分钟。抽出上清液并丢弃。 </li><li>重新悬浮细胞在无菌室温PBS中所需的浓度。佛r中的DNA释放测定在第2节以每毫升5×10 6个细胞中所述，重悬。 </li><li>如果需要的话，直接转移细胞的一小体积或使用cytocentrifuge到载玻片。允许细胞干燥并使用根据制造商的指令的快速固定和染色试剂盒染色。如果在显微镜下观察的嗜中性粒细胞分离已经成功，有核细胞的至少95％应是粒细胞（嗜中性粒细胞，嗜碱性粒细胞，嗜酸性粒细胞）以最小的红细胞的污染。 </li></ol> 3. DNA释放分析<ol><li>中性粒细胞后，立即隔离设立DNA释放试验。 </li><li>如果细胞聚集存在于原液通过光学显微镜检查，立即设置在测定前通过无菌70微米无菌过滤器通过细胞悬浮液。 </li><li>到无菌的96孔板的每个测试孔中，加入5×10 4个细胞/孔;激动剂和罗斯威尔公园备忘录不含酚红和补充有0.5％热灭活的胎牛血清100-200微升的最终体积里亚尔研究所-1640（RPMI）培养基。包括其中的中性粒细胞原液是由等体积的PBS替换每激动剂至少两个空白孔。注意，对于每个激动剂设置空白孔是在通过用荧光测定激动剂排除激动剂或干扰的DNA污染重要。 </li><li>孵育在39℃下，在二氧化碳（4％）培养箱中30分钟。 </li><li>在所需的浓度和细胞不可渗透的核酸染料添加激动剂。注意细胞不可渗透的染料的最佳浓度将不同的核酸染料之间变化。其中激动剂由等体积的培养基代替非刺激对照应包括在每个实验。 注意:所希望的是稀释在培养基中的类似体积的激动剂保持孔之间是一致的条件。 200最终也卷＆＃181; l已成功使用，如果这个被改变，以及量应保持在所有条件相同。佛波醇-12-肉豆蔻酸酯-13-乙酸酯（PMA）（最终浓度≥0.1微米）或血小板活化因子（PAF）（最终浓度≥31微米）可被用作阳性对照。激动剂应至少一式两份进行测定。 </li><li>孵育在39℃。用酶标仪在2小时后，或在所需的时间间隔测量荧光。需要注意的是最佳的时间间隔将与所用激动剂而变化。 注:波长将依赖于所用的染料。 </li><li>计算平均荧光之前减去空白荧光。 </li><li>允许个人之间以及板之间的比较，由非刺激孔的平均荧光除以刺激孔的平均荧光计算荧光的倍数变化。 </li></ol>

<ol>
	<li>Schiffman, J. D., Breen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+oncology:+what+dogs+and+other+species+can+teach+us+about+humans+with+cancer.">Comparative oncology: what dogs and other species can teach us about humans with cancer.</a> Philos Trans Rl Soc B Biol Sci. 370, 1673 (2015).</li><li>Williams, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+of+canine+leucocyte+antigens:+a+significant+advance+in+canine+immunology.">Studies of canine leucocyte antigens: a significant advance in canine immunology.</a> Vet J. 153 (1), 31-39 (1997).</li><li>Eckhart, 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=Duplication+of+the+caspase-12+prodomain+and+inactivation+of+NLRC4/IPAF+in+the+dog.">Duplication of the caspase-12 prodomain and inactivation of NLRC4/IPAF in the dog.</a> Biochem Biophys Res Commun. 384 (2), 226-230 (2009).</li><li>Eckhart, 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=Identification+of+novel+mammalian+caspases+reveals+an+important+role+of+gene+loss+in+shaping+the+human+caspase+repertoire.">Identification of novel mammalian caspases reveals an important role of gene loss in shaping the human caspase repertoire.</a> Mol Biol Evol. 25 (5), 831-841 (2008).</li><li>Brinkmann, V., 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=Neutrophil+extracellular+traps+kill+bacteria.">Neutrophil extracellular traps kill bacteria.</a> Science. 303 (5663), 1532-1535 (2004).</li><li>Brinkmann, V., Zychlinsky, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neutrophil+extracellular+traps:+is+immunity+the+second+function+of+chromatin.">Neutrophil extracellular traps: is immunity the second function of chromatin.</a> J Cell Biol. 198 (5), 773-783 (2012).</li><li>Chuammitri, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chicken+heterophil+extracellular+traps+(HETs):+novel+defense+mechanism+of+chicken+heterophils.">Chicken heterophil extracellular traps (HETs): novel defense mechanism of chicken heterophils.</a> Vet Immunol Immunopathol. 129 (1-2), 126-131 (2009).</li><li>Pali&#263;, D., Ostoji&#263;, J., Andreasen, C. B., Roth, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fish+cast+NETs:+neutrophil+extracellular+traps+are+released+from+fish+neutrophils.">Fish cast NETs: neutrophil extracellular traps are released from fish neutrophils.</a> Dev Comp Immunol. 31 (8), 805-816 (2007).</li><li>Poirier, A. C., Schmitt, P., Rosa, R. D., Vanhove, A. S., Kieffer-Jaquinod, S., Rubio, T. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antimicrobial+histones+and+DNA+traps+in+invertebrate+immunity:+evidences+in+Crassostrea+gigas.">Antimicrobial histones and DNA traps in invertebrate immunity: evidences in Crassostrea gigas.</a> J Biol Chem. 289 (36), 24821-24831 (2014).</li><li>Robb, C. T., Dyrynda, E. A., Gray, R. D., Rossi, A. G., Smith, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invertebrate+extracellular+phagocyte+traps+show+that+chromatin+is+an+ancient+defense+weapon.">Invertebrate extracellular phagocyte traps show that chromatin is an ancient defense weapon.</a> Nat Commun. 5, 4627 (2014).</li><li>Kaplan, M. J., Radic, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neutrophil+extracellular+traps:+double-edged+swords+of+innate+immunity.">Neutrophil extracellular traps: double-edged swords of innate immunity.</a> J Immunol. 189 (6), 2689-2695 (2012).</li><li>Menegazzi, R., Decleva, E., Dri, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Killing+by+neutrophil+extracellular+traps:+fact+or+folklore?.">Killing by neutrophil extracellular traps: fact or folklore?.</a> Blood. 119 (5), 1214-1216 (2012).</li><li>Parker, H., Albrett, A. M., Kettle, A. J., Winterbourn, C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myeloperoxidase+associated+with+neutrophil+extracellular+traps+is+active+and+mediates+bacterial+killing+in+the+presence+of+hydrogen+peroxide.">Myeloperoxidase associated with neutrophil extracellular traps is active and mediates bacterial killing in the presence of hydrogen peroxide.</a> J Leukoc Biol. 91 (3), 369-376 (2012).</li><li>Martinod, K., Wagner, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thrombosis:+tangled+up+in+NETs.">Thrombosis: tangled up in NETs.</a> Blood. 123 (18), 2768-2776 (2014).</li><li>Pratesi, F., 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=Antibodies+from+patients+with+rheumatoid+arthritis+target+citrullinated+histone+4+contained+in+neutrophils+extracellular+traps.">Antibodies from patients with rheumatoid arthritis target citrullinated histone 4 contained in neutrophils extracellular traps.</a> Ann Rheum Dis. 73 (7), 1414-1422 (2014).</li><li>Nauseef, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+human+neutrophils+from+venous+blood.">Isolation of human neutrophils from venous blood.</a> Methods Mol Biol. 1124, 13-18 (2014).</li><li>Gray, R. D., 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=Activation+of+conventional+protein+kinase+C+(PKC)+is+critical+in+the+generation+of+human+neutrophil+extracellular+traps.">Activation of conventional protein kinase C (PKC) is critical in the generation of human neutrophil extracellular traps.</a> J Inflamm (Lond). 10 (1), 12 (2013).</li><li>Jeffery, U., 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=Dogs+cast+NETs+too:+Canine+neutrophil+extracellular+traps+in+health+and+immune-mediated+hemolytic+anemia.">Dogs cast NETs too: Canine neutrophil extracellular traps in health and immune-mediated hemolytic anemia.</a> Vet Immunol Immunopathol. 168 (3-4), 262-268 (2015).</li><li>McCracken, J. M., Allen, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+human+neutrophil+apoptosis+and+lifespan+in+health+and+disease.">Regulation of human neutrophil apoptosis and lifespan in health and disease.</a> J Cell Death. 7, 15-23 (2014).</li></ol>

作者什么都没有透露。

提出的DNA释放法是外DNA一个容易量化分析。该方法改编自用于评估其他物种NET形成类似的技术，但离心速度，激动剂浓度和温育时间已被改变，以优化使用的方法与犬粒细胞8,17,18。类似的调整可以作出适应其他物种的方法。当与其他方法测量NETosis如流式细胞术或图像分析相比，该法是简单又便宜。该方法也并不需要对.NET组件抗体，所以非常适合在狗使用为谁商业化生产的，经过验证的?...

有超过7000万只宠物狗在美国独自1。为尊贵的家族成员，这些动物经常收到尖端的医疗护理。同样，因为他们分享我们的环境，狗可以提供深入了解人类疾病1的发病机理和治疗。然而，无论是在人类医学成兽医治疗或反之亦然翻译的发现，它彻底表征即使在高度保守的系统种类的变化，例如先天免疫应答是重要的。的犬和人先天免疫系统之间的差异例子包括中性粒细胞的狗2高表达CD4;缺乏胞质鞭毛传感器IPAF犬3功能同系物的和在食肉动物4胱天蛋白酶1/4混合的表达。 中性粒细胞胞外陷阱（英语教师）是先天免疫5的相对最近发现的组成部分。篮网是网络S IN响应释放到大范围炎性或传染性刺激6的DNA的核和颗粒状蛋白质。网状结构已被证实在许多物种包括鸡7，鱼8，软体动物9和acoelomates 10，但也有物种变体。例如，嗜中性粒细胞的小鼠更响应缓慢NETosis刺激比人类嗜中性粒细胞，形成弥漫性减弱英语教师11。有一个庞大的身躯从多个物种蚊帐坑害微生物和更具争议可以直接参与杀灭病原体12,13证据。然而，.NET组件也增强了组织的损伤，促进血栓形成，并作为自身抗原14,15。教师的有益和有害作用之间的平衡可能不同的疾病和不同物种之间变化，这表明，调查无论是在物种和感兴趣条件母语是重要的。 在这里，我们描述了诱导和中性粒细胞犬测量母语释放一个简单的协议。此方法类似于那些用于分离嗜中性粒细胞16和在其他物种中诱发NETosis，但如激动剂浓度和温育时间条件已为犬嗜中性粒细胞进行了优化。类似的NET定量的DNA释放测定也已在其它物种中描述，但这里介绍的方法也为狗8,17,18优化。

<table border="0" cellpadding="0" cellspacing="0" width="546">
	<colgroup>
		<col />
		<col />
		<col span="2" />
	</colgroup>
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:204px;">Plastic Whole Blood tube with spray-coated K2EDTA</td>
			<td style="width:215px;">BD</td>
			<td style="width:64px;">367835</td>
			<td style="width:64px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Histopaque-1077</td>
			<td>Sigma-Aldrich</td>
			<td>10771</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Dextran-500</td>
			<td>Accurate chemical and scientific corp.</td>
			<td>AN228410</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Phosphate buffered saline</td>
			<td>ThermoFisher scientific</td>
			<td>20012043</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Fetal bovine calf serum, heat inactivated</td>
			<td>ThermoFisher scientific</td>
			<td>10100139</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">RPMI Media 1640, without phenol red or L-glutamine</td>
			<td>ThermoFisher scientific</td>
			<td>32404-014</td>
			<td>Should be free from phenol red</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">96 well flat bottomed sterile polystyrene plate</td>
			<td>Falcon</td>
			<td>353072</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Phorbol 12-myristate 13-acetate</td>
			<td>Sigma-Aldrich</td>
			<td>P1585</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Platelet activating factor</td>
			<td>Sigma-Aldrich</td>
			<td>P4904</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">SYTOX Green Nucleic Acid Stain</td>
			<td>ThermoFisher scientific</td>
			<td>S7020</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Synergy 2 Multi-Mode Reader</td>
			<td>BioTek</td>
			<td>NA</td>
			<td></td>
		</tr>
	</tbody>
</table>

a simple fluorescence assay for quantification of canine neutrophil extracellular trap release

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

使用该协议，应该有在荧光与阳性对照，PMA和PAF刺激嗜中性粒细胞后强烈的倍数变化。如在图1B中 ，犬嗜中性粒细胞的刺激所示用31微米的PAF 1小时的结果，平均4.0倍的增加的荧光与未刺激细胞（范围2.0-5.8中，n = 5只犬）18进行比较。 PMA在0.1微米（ 图1A）是较慢激动剂不导致荧光的增加，直到2小时，但最终会产生荧光的类似倍的增加（平?...

Watch this Scientific Journal Video about A Simple Fluorescence Assay for Quantification of Canine Neutrophil Extracellular Trap Release at JoVE.com

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

中性粒细胞胞外陷阱（英语教师）是DNA，组蛋白和中性粒细胞的蛋白质网络。虽然先天免疫反应的一个组成部分，母语有牵连的自身免疫和血栓形成。这个协议描述了犬嗜中性粒细胞的分离和使用微板荧光测定教师的量化的简单方法。

一个简单的荧光试验犬中性粒细胞胞外陷阱里放的量化

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

a-simple-fluorescence-assay-for-quantification-canine-neutrophil

Research

JoVE Journal

Immunology and Infection

8.0K 次观看.  Iowa State University. 中性粒细胞胞外陷阱（英语教师）是DNA，组蛋白和中性粒细胞的蛋白质网络。虽然先天免疫反应的一个组成部分，母语有牵连的自身免疫和血栓形成。这个协议描述了犬嗜中性粒细胞的分离和使用微板荧光测定教师的量化的简单方法。 

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

Neutrophil Extracellular Traps: How to Generate and Visualize Them

Neutrophil granulocytes are the most abundant group of leukocytes in the peripheral blood. As professional phagocytes, they engulf bacteria and kill them intracellularly when their antimicrobial granules fuse with the phagosome. We found that neutrophils have an additional way of killing microorganisms: upon activation, they release granule proteins and chromatin that together form extracellular fibers that bind pathogens. These novel structures, or Neutrophil Extracellular Traps (NETs), degrade virulence factors and kill bacteria1, fungi2 and parasites3. The structural backbone of NETs is DNA, and they are quickly degraded in the presence of DNases. Thus, bacteria expressing DNases are more virulent4. Using correlative microscopy combining TEM, SEM, immunofluorescence and live cell imaging techniques, we could show that upon stimulation, the nuclei of neutrophils lose their shape and the eu- and heterochromatin homogenize. Later, the nuclear envelope and the granule membranes disintegrate allowing the mixing of NET components. Finally, the NETs are released as the cell membrane breaks. This cell death program (NETosis) is distinct from apoptosis and necrosis and depends on the generation of Reactive Oxygen Species by NADPH oxidase5. 
Neutrophil extracellular traps are abundant at sites of acute inflammation. NETs appear to be a form of innate immune response that bind microorganisms, prevent them from spreading, and ensure a high local concentration of antimicrobial agents to degrade virulence factors and kill pathogens thus allowing neutrophils to fulfill their antimicrobial function even beyond their life span. There is increasing evidence, however, that NETs are also involved in diseases that range from auto-immune syndromes to infertility6.
We describe methods to isolate Neutrophil Granulocytes from peripheral human blood7 and stimulate them to form NETs. Also we include protocols to visualize the NETs in light and electron microscopy.

Neutrophil Extracellular Traps (NETs) are an important innate immune mechanism to fight pathogenic bacteria, fungi and parasites. Here we describe methods to isolate neutrophil granulocytes from human blood and to activate them to form NETs. We present preparation techniques to visualize NETs in light and electron microscopy.

嗜中性粒细胞胞外的陷阱：如何生成和可视化

Neutrophil granulocytes are the most abundant group of leukocytes in the peripheral blood. As professional phagocytes, they engulf bacteria and kill them ...

科研

免疫与感染

Concurrent Quantification of Cellular and Extracellular Components of Biofilms

Confocal laser scanning microscopy (CLSM) is a powerful tool for investigation of biofilms. Very few investigations have successfully quantified concurrent distribution of more than two components within biofilms because: 1)&#160;selection of fluorescent dyes having minimal spectral overlap is complicated, and 2)&#160;quantification of multiple fluorochromes poses a multifactorial problem. Objectives: Report a methodology to quantify and compare concurrent 3-dimensional distributions of three cellular/extracellular components of biofilms grown on relevant substrates. Methods: The method consists of distinct, interconnected steps involving biofilm growth, staining, CLSM imaging, biofilm structural analysis and visualization, and statistical analysis of structural parameters. Biofilms of Streptococcus mutans (strain UA159) were grown for 48 hr on sterile specimens of Point 4 and TPH3 resin composites. Specimens were subsequently immersed for 60 sec in either Biot&#232;ne PBF (BIO) or Listerine Total Care (LTO) mouthwashes, or water (control group; n=5/group). Biofilms were stained with fluorochromes for extracellular polymeric substances, proteins and nucleic acids before imaging with CLSM. Biofilm structural parameters calculated using ISA3D image analysis software were biovolume and mean biofilm thickness. Mixed models statistical analyses compared structural parameters between mouthwash and control groups (SAS software; &#945;=0.05). Volocity software permitted visualization of 3D distributions of overlaid biofilm components (fluorochromes). Results: Mouthwash BIO produced biofilm structures that differed significantly from the control (p&#60;0.05) on both resin composites, whereas LTO did not produce differences (p&#62;0.05) on either product. Conclusions: This methodology efficiently and successfully quantified and compared concurrent 3D distributions of three major components within S. mutans biofilms on relevant substrates, thus overcoming two challenges to simultaneous assessment of biofilm components. This method can also be used to determine the efficacy of antibacterial/antifouling agents against multiple biofilm components, as shown using mouthwashes. Furthermore, this method has broad application because it facilitates comparison of 3D structures/architecture of biofilms in a variety of disciplines.

A protocol for the concurrent quantification and comparison of three cellular and extracellular components within biofilms is presented. The methodology involves the use of confocal laser scanning microscopy, biofilm structural analysis and visualization software, and statistical analysis software.

细胞和生物膜细胞外成分的定量并发

Confocal laser scanning microscopy (CLSM) is a powerful tool for investigation of biofilms. Very few investigations have successfully quantified ...

In vitro Coculture Assay to Assess Pathogen Induced Neutrophil Trans-epithelial Migration

Mucosal surfaces serve as protective barriers against pathogenic organisms.&#160;Innate immune responses are activated upon sensing pathogen leading to the infiltration of tissues with migrating inflammatory cells, primarily neutrophils.&#160;This process has the potential to be destructive to tissues if excessive or held in an unresolved state.&#160; Cocultured in vitro models can be utilized to study the unique molecular mechanisms involved in pathogen induced neutrophil trans-epithelial migration.&#160;This type of model provides versatility in experimental design with opportunity for controlled manipulation of the pathogen, epithelial barrier, or neutrophil.&#160;Pathogenic infection of the apical surface of polarized epithelial monolayers grown on permeable transwell filters instigates physiologically relevant basolateral to apical trans-epithelial migration of neutrophils applied to the basolateral surface.&#160;The in vitro model described herein demonstrates the multiple steps necessary for demonstrating neutrophil migration across a polarized lung epithelial monolayer that has been infected with pathogenic P. aeruginosa (PAO1).&#160;Seeding and culturing of permeable transwells with human derived lung epithelial cells is described, along with isolation of neutrophils from whole human blood and culturing of PAO1 and nonpathogenic K12 E. coli (MC1000).&#160; The emigrational process and quantitative analysis of successfully migrated neutrophils that have been mobilized in response to pathogenic infection is shown with representative data, including positive and negative controls.&#160;This in vitro model system can be manipulated and applied to other mucosal surfaces.&#160;Inflammatory responses that involve excessive neutrophil infiltration can be destructive to host tissues and can occur in the absence of pathogenic infections.&#160;A better understanding of the molecular mechanisms that promote neutrophil trans-epithelial migration through experimental manipulation of the in vitro coculture assay system described herein has significant potential to identify novel therapeutic targets for a range of mucosal infectious as well as inflammatory diseases.

In vitro Coculture Assay to Assess Pathogen Induced Neutrophil Trans-epithelial Migration

Neutrophil trans-epithelial migration in response to mucosal bacterial infection contributes to epithelial injury and clinical disease.&#160;An in vitro model has been developed that combines pathogen, human neutrophils, and polarized human epithelial cell layers grown on transwell filters to facilitate investigations towards unraveling the molecular mechanisms orchestrating this phenomenon.

体外 共生分析评估病原体诱导中性粒细胞跨上皮迁移

Mucosal surfaces serve as protective barriers against pathogenic organisms.&#160;Innate immune responses are activated upon sensing pathogen leading to ...

Human Neutrophil Flow Chamber Adhesion Assay

Neutrophil firm adhesion to endothelial cells plays a critical role in inflammation in both health and disease. The process of neutrophil firm adhesion involves many different adhesion molecules including members of the &beta;2 integrin family and their counter-receptors of the ICAM family. Recently, naturally occurring genetic variants in both &beta;2 integrins and ICAMs are reported to be associated with autoimmune disease. Thus, the quantitative adhesive capacity of neutrophils from individuals with varying allelic forms of these adhesion molecules is important to study in relation to mechanisms underlying development of autoimmunity. Adhesion studies in flow chamber systems can create an environment with fluid shear stress similar to that observed in the blood vessel environment in vivo. Here, we present a method using a flow chamber assay system to study the quantitative adhesive properties of human peripheral blood neutrophils to human umbilical vein endothelial cell (HUVEC) and to purified ligand substrates. With this method, the neutrophil adhesive capacities from donors with different allelic variants in adhesion receptors can be assessed and compared. This method can also be modified to assess adhesion of other primary cell types or cell lines.

A method of quantitating neutrophil adhesion is reported. This method creates a dynamic flow environment similar to that encountered in a blood vessel. It allows the investigation of neutrophil adhesion to either purified adhesion molecules (ligand) or endothelial cell substrate (HUVEC) in a context similar to the in vivo environment with sheer stress.

人中性粒细胞流动室粘附实验

Neutrophil firm adhesion to endothelial cells plays a critical role in inflammation in both health and disease. The process of neutrophil firm adhesion ...

Simplified Human Neutrophil Extracellular Traps (NETs) Isolation and Handling

Neutrophil Extracellular Traps (NETs) have been recently identified as part of the neutrophil&#8217;s antimicrobial armamentarium. Apart from their role in fighting infections, recent research has demonstrated that they may be involved in many other disease processes, including cancer progression. Isolating purified NETs is a crucial element to allow the study of these functions.
In this video, we demonstrate a simplified method of cell free NET isolation from human whole blood using readily available reagents. Isolated NETs can then be used for immunofluorescence staining, blotting or various functional assays. This enables an assessment of their biologic properties in the absence of the potential confounding effects of neutrophils themselves.
A density gradient separation technique is employed to isolate neutrophils from healthy donor whole blood. Isolated neutrophils are then stimulated by phorbol 12-myristate 13-acetate (PMA) to induce NETosis. Activated neutrophils are then discarded, and a cell-free NET stock is obtained.
We then demonstrate how isolated NETs can be used in an adhesion assay with A549 human lung cancer cells. The NET stock is used to coat the wells of a 96 well cell culture plate O/N, and after ensuring an adequate NET monolayer formation on the bottom of the wells, CFSE labeled A549 cells are added. Adherent cells are quantified using a Nikon TE300 fluorescent microscope. In some wells, 1000U DNAse1 is added 10 min before counting to degrade NETs

Simplified Human Neutrophil Extracellular Traps NETs Isolation and Handling

In the following protocol, we describe a very simple way to isolate Neutrophil Extracellular traps (NETs) from human whole blood using readily available reagents. We then demonstrate how the isolated NETs can be used in an in vitro adhesion assay with cancer cells.

简化人力中性粒细胞胞外陷阱（英语教师）分离和处理

Neutrophil Extracellular Traps (NETs) have been recently identified as part of the neutrophil&#8217;s antimicrobial armamentarium. Apart from their role ...

In Vitro Canine Neutrophil Extracellular Trap Formation: Dynamic and Quantitative Analysis by Fluorescence Microscopy

In response to invading pathogens, neutrophils release neutrophil extracellular traps (NETs), which are extracellular networks of DNA decorated with histones and antimicrobial proteins. Excessive NET formation (NETosis) and citH3 release during sepsis is associated with multiple organ dysfunction and mortality in mice and humans but its implications in dogs are unknown. Herein, we describe a technique to isolate canine neutrophils from whole blood for observation and quantification of NETosis. Leukocyte-rich plasma, generated by dextran sedimentation, is separated by commercially available density gradient separation media and granulocytes collected for cell count and viability testing. To observe real-time NETosis in live neutrophils, cell permeant and cell impermeant fluorescent nucleic acid stains are added to neutrophils activated either by lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA). Changes in nuclear morphology and NET formation are observed over time by fluorescence microscopy. In vitro NETosis is further characterized by co-colocalization of cell-free DNA (cfDNA), myeloperoxidase (MPO) and citrullinated histone H3 (citH3) using a modified double-immunolabelling protocol. To objectively quantify NET formation and citH3 expression using fluorescence microscopy, NETs and citH3-positive cells are quantified in a blinded manner using available software. This technique is a specific assay to evaluate the in vitro capacity of canine neutrophils to undergo NETosis.

In Vitro Canine Neutrophil Extracellular Trap Formation: Dynamic and Quantitative Analysis by Fluorescence Microscopy

We describe methods to isolate canine neutrophils from whole blood and visualize NET formation in live neutrophils using fluorescence microscopy. Also described are protocols to quantify NET formation and citrullinated histone H3 (citH3) expression using immunofluorescence microscopy.

体外犬中性粒细胞胞外陷阱的形成: 荧光显微镜动态定量分析

In response to invading pathogens, neutrophils release neutrophil extracellular traps (NETs), which are extracellular networks of DNA decorated with ...

Quantification of Efferocytosis by Single-cell Fluorescence Microscopy

Studying the regulation of efferocytosis requires methods that are able to accurately quantify the uptake of apoptotic cells and to probe the signaling and cellular processes that control efferocytosis. This quantification can be difficult to perform as apoptotic cells are often efferocytosed piecemeal, thus necessitating methods which can accurately delineate between the efferocytosed portion of an apoptotic target versus residual unengulfed cellular fragments. The approach outlined herein utilizes dual-labeling approaches to accurately quantify the dynamics of efferocytosis and efferocytic capacity of efferocytes such as macrophages. The cytosol of the apoptotic cell is labeled with a cell-tracking dye to enable monitoring of all apoptotic cell-derived materials, while surface biotinylation of the apoptotic cell allows for differentiation between internalized and non-internalized apoptotic cell fractions. The efferocytic capacity of efferocytes is determined by taking fluorescent images of live or fixed cells and quantifying the amount of bound versus internalized targets, as differentiated by streptavidin staining. This approach offers several advantages over methods such as flow cytometry, namely the accurate delineation of non-efferocytosed versus efferocytosed apoptotic cell fractions, the ability to measure efferocytic dynamics by live-cell microscopy, and the capacity to perform studies of cellular signaling in cells expressing fluorescently-labeled transgenes. Combined, the methods outlined in this protocol serve as the basis for a flexible experimental approach that can be used to accurately quantify efferocytic activity and interrogate cellular signaling pathways active during efferocytosis.

Efferocytosis, the phagocytic removal of apoptotic cells, is required to maintain homeostasis and is facilitated by receptors and signaling pathways that allow for the recognition, engulfment, and internalization of apoptotic cells. Herein, we present a fluorescence microscopy protocol for the quantification of efferocytosis and the activity of efferocytic signaling pathways.

单细胞荧光显微镜定量 Efferocytosis 的研究

Studying the regulation of efferocytosis requires methods that are able to accurately quantify the uptake of apoptotic cells and to probe the signaling ...

Automated Image-Based Quantification of Neutrophil Extracellular Traps Using NETQUANT

Neutrophil extracellular traps (NETs) are web-like antimicrobial structures consisting of DNA and granule derived antimicrobial proteins. Immunofluorescence microscopy and image-based quantification methods remain important tools to quantitate neutrophil extracellular trap formation. However, there are key limitations to the immunofluorescence-based methods that are currently available for quantifying NETs. Manual methods of image-based NET quantification are often subjective, prone to error and tedious for users, especially non-experienced users. Also, presently available software options for quantification are either semi-automatic or require training prior to operation. Here, we demonstrate the implementation of an automated immunofluorescence-based image quantification method to evaluate NET formation called NETQUANT. The software is easy to use and has a user-friendly graphical user interface (GUI). It considers biologically relevant parameters such as an increase in the surface area and DNA:NET marker protein ratio, and nuclear deformation to define NET formation. Furthermore, this tool is built as a freely available app, and allows for single-cell resolution quantification and analysis.

Here, we present a protocol for generating neutrophil extracellular traps (NETs) and operating NETQUANT, a fully automatic software option for quantification of NETs in immunofluorescence images.

使用 NETQUANT 对中性粒细胞外陷阱的自动基于图像的定量

Neutrophil extracellular traps (NETs) are web-like antimicrobial structures consisting of DNA and granule derived antimicrobial proteins. ...

A High-throughput Assay to Assess and Quantify Neutrophil Extracellular Trap Formation

Neutrophil extracellular traps (NETs) are immunogenic extracellular DNA structures that can be released by neutrophils upon a wide variety of triggers. NETs have been demonstrated to serve as an important host defense mechanism that traps and kills microorganisms. On the other hand, they have been implicated in diverse systemic autoimmune diseases. NETs are immunogenic and toxic structures that contain a pool of relevant autoantigens including anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) and systemic lupus erythematosus (SLE). Different forms of NETs can be induced depending on the stimulus. The amount of NETs can be quantified using different techniques including measuring DNA release in supernatants, measuring DNA-complexed with NET-molecules like myeloperoxidase (MPO) or neutrophil elastase (NE), measuring the presence of citrullinated histones by fluorescence microscopy, or flow cytometric detection of NET-components which all have different features regarding their specificity, sensitivity, objectivity, and quantity. Here is a protocol to quantify ex vivo NET formation in a highly-sensitive, high-throughput manner by using three-dimensional immunofluorescence confocal microscopy. This protocol can be applied to address various research questions about NET formation and degradation in health and disease.

This protocol describes a highly sensitive and high throughput neutrophil extracellular trap (NET) assay for the semi-automated quantification of ex vivo NET formation by immunofluorescence three-dimensional confocal microscopy. This protocol can be used to evaluate NET formation and degradation after different stimuli and can be used to study potential NET-targeted therapies.

一种评估和定量中性粒细胞外细胞陷阱形成的高通量检测

Neutrophil extracellular traps (NETs) are immunogenic extracellular DNA structures that can be released by neutrophils upon a wide variety of triggers. ...

In Vitro Stimulation and Visualization of Extracellular Trap Release in Differentiated Human Monocyte-derived Macrophages

The release of extracellular traps (ETs) by neutrophils has been identified as a contributing factor to the development of diseases related to chronic inflammation. Neutrophil ETs (NETs) consist of a mesh of DNA, histone proteins, and various granule proteins (i.e., myeloperoxidase, elastase, and cathepsin G). Other immune cells, including macrophages, can also produce ETs; however, to what extent this occurs in vivo and whether macrophage extracellular traps (METs) play a role in pathological mechanisms has not been examined in detail. To better understand the role of METs in inflammatory pathologies, a protocol was developed for visualizing MET release from primary human macrophages in vitro, which can also be exploited in immunofluorescence experiments. This allows further characterization of these structures and their comparison to ETs released from neutrophils. Human monocyte-derived macrophages (HMDM) produce METs upon exposure to different inflammatory stimuli following differentiation to the M1 pro-inflammatory phenotype. The release of METs can be visualized by microscopy using a green fluorescent nucleic acid stain that is impermeant to live cells (e.g., SYTOX green). Use of freshly isolated primary macrophages, such as HMDM, is advantageous in modeling in vivo inflammatory events that are relevant to potential clinical applications. This protocol can also be used to study MET release from human monocyte cell lines (e.g., THP-1) following differentiation into macrophages with phorbol myristate acetate or other macrophage cell lines (e.g., the murine macrophage-like J774A.1 cells).

Presented here is a protocol to detect macrophage extracellular trap (MET) production in live cell culture using microscopy and fluorescence staining. This protocol can be further extended to examine specific MET protein markers by immunofluorescence staining.

分化人类单细胞衍生巨噬细胞中细胞外陷阱释放的体外刺激与可视化

The release of extracellular traps (ETs) by neutrophils has been identified as a contributing factor to the development of diseases related to chronic ...