Name: an in vitro caseum binding assay that predicts drug penetration in tuberculosis lesions
Uploaded: 2017-05-08T15:00:00.000+00:00
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Description: Watch this Scientific Journal Video about An In Vitro Caseum Binding Assay that Predicts Drug Penetration in Tuberculosis Lesions at JoVE.com

我们要感谢强生公司，结核病联盟，阿斯利康Zeneca，Rib-X和Trius治疗公司分别提供床上苯胺，PA-824（pretomanid），AZD5847，radezolid和tedizolid。 Brendan Prideaux，Matthew Zimmerman，Stephen Juzwin，Emma Rey-Jurado，Nancy Ruel，Leyan Li和Danielle Weiner为MALDI分析，生物分析方法，干酪替代品的制备，化学合成和兔子白蛋白的分离提供了支持。这项工作是由比尔和梅林达·盖茨基金会资助的，拨款为OPP1044966和OPP1024050的V. Dartois，NIH Shared Instrumentation Grant S10OD018072，以及Bill和Melinda Gates基金会以及Wellcome Trust for A卓越中心的联合资助。将发展中世界疾病的潜在优化用于P.Wyatt。

所有动物研究按照指南国立卫生研究院的实验动物护理和使用从NIAID的机构动物护理和使用委员会（NIH），马里兰州贝塞斯达的批准进行。所有涉及结核分枝杆菌的研究是在实验室中的生物安全防护水平3（BSL-3）执行。 1.兔感染模型和Caseum收藏<ol><li>使用鼻式气溶胶曝光系统如前所述感染新西兰白兔结核分枝杆菌 。 12，13允许感染为12-16周进行。稳重用35毫克/千克氯胺酮和5mg / kg的甲苯噻嗪肌内，兔子安乐死与0.22毫升/公斤戊巴比妥钠和苯妥英钠兔子静脉内并与尸检进行。 </li><li>使用镊子和手术刀，从胸部取出CA肺VITY。从每个肺叶，使用手术刀解剖单个腔和大的坏死性肉芽肿。仔细地从空腔和肉芽肿壁上刮掉面包。称量，记录并将样品储存在-20℃的2 mL螺旋管中，直至准备使用。 </li><li> Gamma在干冰上照射3 MegaRad上的感染性病例样本，使其在BSL-2实验室中不受感染和安全使用。 </li></ol> 2.来自THP-1细胞的表皮代谢产物的体外生成<ol><li>在T175细胞培养瓶（80 mL /瓶）中，在RPMI 1640培养基（2 mM L-谷氨酰胺和10％胎牛血清）中培养THP-1单核细胞。将烧瓶在5％CO 2气氛中于37℃孵育3-4天。 </li><li>将来自T175烧瓶的培养物以150×g离心5分钟的两个50mL锥形管中。弃去上清液并将沉淀悬浮在10mL的RPMI 1640培养基中。 </li><li>将5μL该培养液移至含有45μLt的1.5 mL试管中紫苏蓝通过移液彻底混合。将10μL转移到血细胞计数器，并使用光学显微镜（10倍放大）计数活的THP-1单核细胞数（未染色）。计算每毫升培养物的活细胞数。用RPMI培养基稀释至1.25×10 6个细胞/ mL的最终密度。 </li><li>在大细胞培养板（50×10 6个细胞/板）上加入40mL培养物。加入40μL100μMPMA（佛波醇12-肉豆蔻酸乙酯13-乙酸乙酯制备），并使细胞在培养箱中过夜。 注意:PMA的最终浓度为100nM。 </li><li>在乙醇中稀释纯油酸（OA）（0.89 g / mL）至浓度为0.1 M（ 即在968.3μL乙醇中的31.7μLOA）。将此溶液稀释至新鲜预热的RMPI培养基中，浓度为10 mM。将该OA悬浮液稀释至预温至37℃的RPMI培养基中的0.4mM（最终工作浓度）。 </li><li>删除现有媒体和非从细胞培养板中吸收细胞，并轻轻加入40 mL 0.4 mM OA至THP-1巨噬细胞（THP-M）。在培养箱中37℃孵育过夜。 </li><li>使用40倍放大的光学显微镜来目视确认每个THP-M中存在许多脂质体夹杂物。从细胞培养板中取出所有的RPMI培养基，并用50 mL血清移液管用磷酸盐缓冲盐水（PBS）轻轻洗涤贴壁细胞两次。 注意:脂质体在THP-M的细胞质中表现为小的，清晰的球形结构。 </li><li>在PBS中加入40mL 5mM乙二胺四乙酸（EDTA）的PBS。在37℃孵育15分钟。 </li><li>通过使用10 mL血清移液管重复吸取整个板的表面，分离泡沫巨噬细胞（FM）。将细胞悬浮液转移到50mL锥形管中，并以150×g离心5分钟。 </li><li>将细胞沉淀重悬于10mL PBS（第三次PBS洗涤）中并转移到预先称重的15-mL锥形管中。以150 xg再次旋转5分钟。使用血清移液管小心吸出上清液并弃去。 </li><li>将FM颗粒置于3个冻融循环中以裂解细胞并将其在75℃下孵育20-30分钟以使基质中的蛋白质变性。将颗粒储存在-20°C直到准备使用。 </li></ol>快速平衡透析（RED）测定<ol><li>在二甲基亚砜（DMSO）中制备所有测试化合物的10mM储备溶液。在每次测定之前，稀释至DMSO中的500μM工作溶液。 </li><li>称重含有小麦替代颗粒的管。减去空管的重量以得出单独的颗粒的重量。每管添加2-3个金属珠，并使用组织匀浆器以1200冲程/分钟1分钟，破碎干酪或PBS（1:9w / v）中的替代物基质，以达到每种基质的10倍稀释悬浮液。 </li><li> Spike 6.5μL的500试验化合物的μM溶液进匀浆643.5μL达到5μM（≤1％DMSO）和涡流的最终浓度。 </li><li>放置RED插入到基座板。添加药物掺入基质到每个RED插入物的供体腔室（红色环）和350μLPBS到每个接收器的腔室200μL。制备3插入各试验化合物（一式三份样品）。密封板用粘接剂密封板并孵育在37℃下在以200rpm（1×g）离心4小时的恒温。 </li><li>培育后，轻轻上下吹打2-3次的供体和受体室的内容混合。从供体室吸取出匀浆的20μL等分试样，并添加至PBS干净的20μL在1.5mL管（1:1）。类似地，从接收器腔室吸取出PBS样品的20μL的等分试样，并添加至20μL的清洁匀浆（矩阵匹配）。 8 注:矩阵匹配消除了NEED为2条独立的校准曲线（在匀浆和PBS）用于定量分析进行。供体腔的内容可能沉淀一段时间。轻轻由前中吸取吹打混合的内容。 </li></ol> 4. LC-MS定量和数据分析<ol><li>加1的160μL:1甲醇:乙腈含有500毫微克/毫升的双氯芬酸或10ng / mL的维拉帕米（内标），以每管和涡流以沉淀蛋白质。离心机以10,000×g离心5分钟以沉淀沉淀物和上清液转移到96孔用于液相色谱 - 质谱（LCMS）分析深孔板。 7 </li><li>从1-1,000纳米的各试验化合物建立校准曲线，同时保持相同的基质组合物作为样品的上方。量化测试化合物在从使用LC-MS方法的供体和受方腔室的样品的浓度。 </li><li>计算未结合的分数（f u）的 Ôf使用方程1稀释的基质中的药物。使用等式2计算未稀释基质中的f u （ D =稀释因子10）。 14 <img alt="公式1" src="/files/ftp_upload/55559/55559eq1.jpg" /> <img alt="公式2" src="/files/ftp_upload/55559/55559eq2.jpg" /></li><li>使用方程3检查每种化合物的恢复（质量平衡），以鉴定具有稳定性/代谢/非特异性结合问题的化合物。 注意:恢复通常在70％到130％之间。 15 <img alt="公式3" src="/files/ftp_upload/55559/55559eq3.jpg" /></li></ol>

<ol>
	<li>Sacchettini, J. C., Rubin, E. J., Freundlich, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drugs+versus+bugs:+in+pursuit+of+the+persistent+predator+Mycobacterium+tuberculosis.">Drugs versus bugs: in pursuit of the persistent predator Mycobacterium tuberculosis.</a> Nat Rev Microbiol. 6 (1), 41-52 (2008).</li><li>Zhang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Persistent+and+dormant+tubercle+bacilli+and+latent+tuberculosis.">Persistent and dormant tubercle bacilli and latent tuberculosis.</a> Front Biosci. 1 (9), 1136-1156 (2004).</li><li>Aber, V. R., Nunn, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Short+term+chemotherapy+of+tuberculosis.+Factors+affecting+relapse+following+short+term+chemotherapy.">Short term chemotherapy of tuberculosis. Factors affecting relapse following short term chemotherapy.</a> Bull Int Union Tuberc. 53 (4), 276-280 (1978).</li><li>Chang, K. C., Leung, C. C., Yew, W. W., Ho, S. C., Tam, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+nested+case-control+study+on+treatment-related+risk+factors+for+early+relapse+of+tuberculosis.">A nested case-control study on treatment-related risk factors for early relapse of tuberculosis.</a> Am J Respir Crit Care Med. 170 (10), 1124-1130 (2004).</li><li>Dartois, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+path+of+anti-tuberculosis+drugs:+from+blood+to+lesions+to+mycobacterial+cells.">The path of anti-tuberculosis drugs: from blood to lesions to mycobacterial cells.</a> Nature Rev Microbiol. 12 (3), 159-167 (2014).</li><li>Prideaux, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+association+between+sterilizing+activity+and+drug+distribution+into+tuberculosis+lesions.">The association between sterilizing activity and drug distribution into tuberculosis lesions.</a> Nat Med. 21 (10), 1223-1227 (2015).</li><li>Sarathy, J. 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=Prediction+of+Drug+Penetration+in+Tuberculosis+Lesions.">Prediction of Drug Penetration in Tuberculosis Lesions.</a> ACS Infect Dis. 2 (8), 552-563 (2016).</li><li>Waters, N. J., Jones, R., Williams, G., Sohal, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Validation+of+a+rapid+equilibrium+dialysis+approach+for+the+measurement+of+plasma+protein+binding.">Validation of a rapid equilibrium dialysis approach for the measurement of plasma protein binding.</a> J Pharm Sci. 97 (10), 4586-4595 (2008).</li><li>Singh, J. K., Solanki, A., Maniyar, R. C., Banerjee, D., Shirsath, V. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+Equilibrium+Dialysis+(RED):+an+In-vitro+High-Throughput+Screening+Technique+for+Plasma+Protein+Binding+using+Human+and+Rat+Plasma.">Rapid Equilibrium Dialysis (RED): an In-vitro High-Throughput Screening Technique for Plasma Protein Binding using Human and Rat Plasma.</a> J Bioequiv Availab. 14, 1-4 (2012).</li><li>Liu, X., 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=Unbound+drug+concentration+in+brain+homogenate+and+cerebral+spinal+fluid+at+steady+state+as+a+surrogate+for+unbound+concentration+in+brain+interstitial+fluid.">Unbound drug concentration in brain homogenate and cerebral spinal fluid at steady state as a surrogate for unbound concentration in brain interstitial fluid.</a> Drug Metab Dispos. 37 (4), 787-793 (2009).</li><li>Able, S. 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=Receptor+localization,+native+tissue+binding+and+ex+vivo+occupancy+for+centrally+penetrant+P2X7+antagonists+in+the+rat.">Receptor localization, native tissue binding and ex vivo occupancy for centrally penetrant P2X7 antagonists in the rat.</a> Br J Pharmacol. 162 (2), 405-414 (2011).</li><li>Subbian, S., 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=Chronic+pulmonary+cavitary+tuberculosis+in+rabbits:+a+failed+host+immune+response.">Chronic pulmonary cavitary tuberculosis in rabbits: a failed host immune response.</a> Open Biol. 1 (4), 1-14 (2011).</li><li>Via, L. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuberculous+Granulomas+are+Hypoxic+in+Guinea+pigs,+Rabbits,+and+Non-Human+Primates.">Tuberculous Granulomas are Hypoxic in Guinea pigs, Rabbits, and Non-Human Primates.</a> Infect Immun. 76 (6), 2333-2340 (2008).</li><li>Kalvass, J. C., Maurer, T. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+nonspecific+brain+and+plasma+binding+on+CNS+exposure:+implications+for+rational+drug+discovery.">Influence of nonspecific brain and plasma binding on CNS exposure: implications for rational drug discovery.</a> Biopharm Drug Dispos. 23 (8), 327-338 (2002).</li><li>Di, L., Umland, J. P., Trapa, P. E., Maurer, T. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+recovery+on+fraction+unbound+using+equilibrium+dialysis.">Impact of recovery on fraction unbound using equilibrium dialysis.</a> J Pharm Sci. 101 (3), 1327-1335 (2012).</li><li>Lenaerts, A. J., 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=Location+of+persisting+mycobacteria+in+a+Guinea+pig+model+of+tuberculosis+revealed+by+r207910.">Location of persisting mycobacteria in a Guinea pig model of tuberculosis revealed by r207910.</a> Antimicrob Agents Chemother. 51 (9), 3338-3345 (2007).</li><li>Prideaux, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-sensitivity+MALDI-MRM-MS+imaging+of+moxifloxacin+distribution+in+tuberculosis-infected+rabbit+lungs+and+granulomatous+lesions.">High-sensitivity MALDI-MRM-MS imaging of moxifloxacin distribution in tuberculosis-infected rabbit lungs and granulomatous lesions.</a> Anal Chem. 83 (6), 2112-2118 (2011).</li></ol>

没有竞争的经济利益。

肺坏死病灶和空洞肺结核感染的患者含有细菌是顽抗到药物治疗的亚群。这些结构的干酪性芯是用于在细胞外环境中携带这些持留尤其负责。抗细菌剂为这些远程位置的16有利分布被认为是肺结核药物疗效的重要决定因素。在此之前协议的验证，没有体外技术，可以预测干酪样病变的药物发现的化合物的分布可用。其结果是，在这些关键病灶药物分布的评价在很大程度上?...

肺结核病的治疗需要的药物有效的分配到不同类型的病变。坏死性病变和腔包含窝藏毒品宽容或"老大难"细菌的亚群干酪中心。 1，2空洞病与劣质治愈率和预后较差。 3，4以前的研究表明，使用定量和成像技术，即穿透caseum的能力而变化显著从一个药物类到另一个。 5,6这些方法，但是，需要使用动物感染模型是缓慢而乏味的。测量药物结合到离体 caseum 在体外测定的目的。这种结合被发现成反比地干酪样肉芽肿药物渗透和相互关联的，因此，是作为预测工具。 7 平衡透析被认为是黄金标准的方法来血浆蛋白结合研究。快速平衡透析（RED）装置提供进行这种测定的一种快速，易于使用，可靠的系统。 8所述的装置由两个部件组成:单次使用的，由通过半透膜的垂直筒2个分隔室的一次性刀片;和可重复使用的基板，其可容纳在一个时间48点的插入物。透析膜具有8kDa的分子量截止（MWCO），是理想的药物 - 大分子结合研究。膜隔室的高表面积 - 体积比允许快速透析和平衡。两个插入件和底板已经验证为最小的非特异性结合。用生物分析技术RED设备的组合提供了药物在p中未结合的级分的精确估计lasma。 8,9 虽然最初设计用于测量血浆蛋白结合，该RED设备已在若干组织结合研究使用匀浆使用。 10，11在这个协议中，我们测量药物结合到caseum，坏死碎屑从坏死损害和结核病感染的兔的空腔切除。干酪性材料的所述无细胞和非血管性质可以很容易地均匀成均匀的悬浮液，其与测定兼容。 鉴于caseum是乏味的，以产生和来之不易，该协议也被验证为与从泡沫巨噬细胞制备的替代矩阵使用。 THP-1单核细胞衍生的巨噬细胞与油酸诱导的积累，让他们自己的"泡沫"外观的多个脂质体。这些脂质加载收获细胞和加工成产生一个矩阵，我们用作表壳的替代品。这项研究表明，与该替代基质结合的药物与结合蛋白质有很好的相关性，有效地模拟了妨碍药物在肉芽肿和空腔的核心中的渗透的体内过程。

<table><tbody><tr><td>New Zealand White Rabbits</td><td>Covance</td><td>-</td><td></td></tr><tr><td>HN878 Mycobacterium tuberculosis</td><td>BEI Resources</td><td>NR-13647&amp;nbsp;</td><td></td></tr><tr><td>Ketathesia (Ketamine) 100 mg/mL C3N</td><td>Henry Schein Animal Health</td><td>56344</td><td></td></tr><tr><td>Anased (Xylazine) 100 mg/mL</td><td>Henry Schein Animal Health</td><td>33198</td><td></td></tr><tr><td>Euthasol (pentobarbital sodium and phenytoin sodium) Solution&amp;nbsp;</td><td>Virbac</td><td>710101</td><td></td></tr><tr><td>THP-1 monocytic cell line</td><td>ATCC</td><td>ATCC TIB-202</td><td></td></tr><tr><td>175 cm&amp;sup2; TC-Treated Flask (T175)</td><td>Fisher Scientific</td><td>T-3400-175</td><td></td></tr><tr><td>RPMI 1640 media w/o glutamine</td><td>Fisher Scientific</td><td>MT-15-040-CV</td><td></td></tr><tr><td>Hyclone Fetal Bovine Serum, Gamma irradiated&amp;nbsp;</td><td>Fisher Scientific</td><td>SH3091003IR</td><td></td></tr><tr><td>Hyclone L-glutamine, 200 mM</td><td>Fisher Scientific</td><td>SH3003401</td><td></td></tr><tr><td>Cellstar TC dish, 145 mm x 20 mm, vented</td><td>Fisher Scientific</td><td>T-2881-1</td><td></td></tr><tr><td>Phorbol 12-myristate 13-acetate (PMA)</td><td>Fisher Scientific</td><td>BP685-1</td><td></td></tr><tr><td>Ethylenediaminetetraacetic acid</td><td>Sigma</td><td>E6758</td><td></td></tr><tr><td>Oleic acid&amp;nbsp;</td><td>Fisher Scientific</td><td>ICN15178101</td><td></td></tr><tr><td>Pierce RED Device Reusable Base Plate</td><td>Fisher Scientific</td><td>PI-89811</td><td></td></tr><tr><td>Pierce RED Device Inserts, 50/box&amp;nbsp;</td><td>Fisher Scientific</td><td>PI-89809</td><td></td></tr><tr><td>Pierce RED insert removal tool&amp;nbsp;</td><td>Fisher Scientific</td><td>89812</td><td></td></tr><tr><td>Adhesive plate seal</td><td>Fisher Scientific</td><td>08-408-240</td><td></td></tr><tr><td>PBS, pH 7.4, 10x 500 mL (Gibco)&amp;nbsp;</td><td>Life Technologies&amp;nbsp;</td><td>10010-049</td><td></td></tr><tr><td>DMSO</td><td>Sigma</td><td>472301</td><td></td></tr><tr><td>Acetonitrile</td><td>Sigma</td><td>34998</td><td></td></tr><tr><td>Methanol</td><td>Sigma</td><td>34860</td><td></td></tr><tr><td>Verapamil hydrochloride</td><td>Sigma</td><td>V4629</td><td></td></tr><tr><td>Diclofenac sodium salt</td><td>Sigma</td><td>93484</td><td></td></tr><tr><td>Trypan Blue Solution, 0.4%</td><td>Fisher Scientific</td><td>15-250-061</td><td></td></tr><tr><td>Ethanol, 200 proof</td><td>Fisher Scientific</td><td>04-355-451</td><td></td></tr><tr><td>2010 Geno/Grinder</td><td>SPEX SamplePrep</td><td>2010</td><td></td></tr><tr><td>Bead Mill Homogenizer Accessory, Metal Bulk Beads</td><td>Fisher Scientific</td><td>15-340-158</td><td></td></tr><tr><td>484R Cobalt 60 Irradiator</td><td>JL Shepard</td><td>7810-484-1</td><td></td></tr><tr><td>INCYTO&amp;nbsp;C-Chip Disposable Hemacytometers</td><td>Fisher Scientific</td><td>22-600-100</td><td></td></tr><tr><td>Upright Light Microscope</td><td>Leica</td><td>DM1000</td><td></td></tr><tr><td>Binary Liquid Chromatography system</td><td>Agilent</td><td>1260</td><td>Multi-compenent</td></tr><tr><td>Mass spectrometer</td><td>AB Sciex</td><td>4000</td><td></td></tr></tbody></table>

an in vitro caseum binding assay that predicts drug penetration in tuberculosis lesions

消除结核病需要能够穿透多层复杂肺部病变的药物治疗方案。空腔和病变的干酪核心中的药物分布尤其重要，因为它们具有耐药细菌的亚群，通常也称为持久性细菌。用于测量结核病变中药物渗透的现有方法涉及与生物分析或成像技术相结合的昂贵且耗时的体内药代动力学研究。提出了与大肠杆菌大分子结合的药物的体外测定作为这种技术的替代方法，因为这种结合阻碍了药物分子通过底物的被动扩散。快速平衡透析是一种用于进行血浆蛋白和组织结合研究的快速可靠的系统。在该方案中，我们使用快速平衡透析（RED）装置来测量药物与排泄物的匀浆的结合从结核病感染的兔子的病变和腔中。该方案还描述了如何从脂质负载的THP-1巨噬细胞产生代替基质来代替小麦蛋白。这种病例/替代结合试验是结核病药物发现的重要工具，可用于帮助研究由其他疾病引起的病变或脓肿中的药物分布。

使用这个协议，我们已经测试了数百种结核病药物开发化合物，以达到预期的穿透性白蛋白的效率。 图1显示了RED测定的基本概念。 RED插入物的透析膜允许未结合的小分子从供体孔扩散到接收器，最终实现两个室之间的平衡。与大分子如蛋白质或脂质结合的小分子被捕获在供体井中。来自两个室的样品的定量分析允许计算小分子或替代基质中每个小分子的未?...

Watch this Scientific Journal Video about An In Vitro Caseum Binding Assay that Predicts Drug Penetration in Tuberculosis Lesions at JoVE.com

An In Vitro Caseum Binding Assay that Predicts Drug Penetration in Tuberculosis Lesions

在这里，我们描述了一种快速平衡透析（RED）方法，用于测量肺结核病变和腔内药物与病例的结合。该方案也与泡沫巨噬细胞衍生基质一起使用，这是一种有效的替代试剂。

一个<em&gt;体外</em&gt; Caseum结合测定，预测药物在渗透结核病变

The eradication of tuberculosis disease requires drug regimens that can penetrate the multiple layers of complex pulmonary lesions. Drug distribution in ...

an-vitro-caseum-binding-assay-that-predicts-drug-penetration

Universidad de Cartagena UDEC

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Education

JoVE Journal

JoVE Core

Pharmacokinetics and Pharmacodynamics

Pharmacology

Immunology and Infection

Unit 1

An In Vitro Caseum Binding Assay that Predicts Drug Penetration in Tuberculosis Lesions

Nonlinear Pharmacokinetics

Introduction to Respiratory System Drugs

SCIENTISTS IN ACTION

11.7K 次观看.  Rutgers. 在这里，我们描述了一种快速平衡透析（RED）方法，用于测量肺结核病变和腔内药物与病例的结合。该方案也与泡沫巨噬细胞衍生基质一起使用，这是一种有效的替代试剂。 

视频: An In Vitro Caseum Binding Assay that Predicts Drug Penetration in Tuberculosis Lesions

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

Despite the availability of therapy and vaccine, tuberculosis (TB) remains one of the most deadly and widespread bacterial infections in the world. Since several decades, the sudden burst of multi- and extensively-drug resistant strains is a serious threat for the control of tuberculosis. Therefore, it is essential to identify new targets and pathways critical for the causative agent of the tuberculosis, Mycobacterium tuberculosis (Mtb) and to search for novel chemicals that could become TB drugs. One approach is to set&#160;up methods suitable for the genetic and chemical screens of large scale libraries enabling the search of a needle in a haystack. To this end, we developed a phenotypic assay relying on the detection of fluorescently labeled Mtb within fluorescently labeled host&#160;cells using automated confocal microscopy. This in vitro assay allows an image based quantification of the colonization process of Mtb&#160;into the host and was optimized for the 384-well microplate format, which is proper for screens of siRNA-, chemical compound- or Mtb mutant-libraries. The images are then processed for multiparametric analysis, which provides read&#160;out inferring on the pathogenesis of Mtb&#160;within host cells.

Here, we describe a phenotypic assay applicable to the High-throughput/High-content screens of small-interfering synthetic RNA (siRNA), chemical compound, and Mycobacterium tuberculosis mutant libraries. This method relies on the detection of fluorescently labeled Mycobacterium tuberculosis within fluorescently labeled host&#160;cell using automated confocal microscopy.

用于适应高通量/高含量筛查的细胞内分枝杆菌定量的微观表型检测

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

科研

免疫与感染

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

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

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

木炭琼脂刃天青分析的可视化分枝杆菌的半定量，中等吞吐量枚举

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

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.

系统抑制剂靶向细胞内的疗效和毒性筛选<em&gt;结核分枝杆菌</em

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

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis

The early drug development process for anti-tuberculosis drugs is hindered by the inefficient translation of compounds with in vitro activity to effectiveness in the clinical setting. This is likely due to a lack of consideration for the physiologically relevant cellular penetration barriers that exist in the infected host. We recently established an alternative infection model that generates large macrophage aggregate structures containing densely packed M. tuberculosis (Mtb) at its core, which was suitable for drug susceptibility testing. This infection model is inexpensive, rapid, and most importantly BSL-2 compatible. Here, we describe the experimental procedures to generate Mtb/macrophage aggregate structures that would produce macrophage-passaged Mtb for drug susceptibility testing. In particular, we demonstrate how this infection system could be directly adapted to the 96-well plate format showing throughput capability for the screening of compound libraries against Mtb. Overall, this assay is a valuable addition to the currently available Mtb drug discovery toolbox due to its simplicity, cost effectiveness, and scalability.

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis

New models and assays that would improve the early drug development process for next-generation anti-tuberculosis drugs are highly desirable. Here, we describe a quick, inexpensive, and BSL-2 compatible assay to evaluate drug efficacy against Mycobacterium tuberculosis that can be easily adapted for high-throughput screening.

高通量兼容检测，以评估对巨噬细胞传代药物疗效<em&gt;结核分枝杆菌</em

The early drug development process for anti-tuberculosis drugs is hindered by the inefficient translation of compounds with in vitro activity to ...

A Tuberculosis Molecular Bacterial Load Assay (TB-MBLA)

Tuberculosis is caused by Mycobacterium tuberculosis (Mtb), a pathogen classified by the United Nations (UN) as a dangerous category B biological substance. For the sake of the workers&#8217; safety, handling of all samples presumed to carry Mtb must be conducted in a containment level (CL) 3 laboratory. The TB molecular bacterial load assay (TB-MBLA) test is a reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) test that quantifies Mtb bacillary load using primers and dual-labelled probes for 16S rRNA. We describe the use of heat inactivation to render TB samples noninfectious while preserving RNA for the TB-MBLA. A 1 mL aliquot of the sputum sample in tightly closed 15 mL centrifuge tubes is boiled for 20 min at either 80 &#176;C, 85 &#176;C, or 95 &#176;C to inactivate Mtb bacilli. Cultivation of the heat inactivated and control (live) samples for 42 days confirmed the death of TB. The inactivated sample is then spiked with 100 &#181;L of the extraction control and RNA is extracted following the standard RNA isolation procedure. No growth was observed in the cultures of heat treated samples. The isolated RNA is subjected to real-time RT-qPCR, which amplifies a specific target in the Mtb 16S rRNA gene, yielding results in the form of quantification cycles (Cq). A standard curve is used to translate Cq into bacterial load, or estimated colony forming units per mL (eCFU/mL). There is an inverse relationship between Cq and the bacterial load of a sample. The limitation is that heat inactivation lyses some cells, exposing the RNA to RNases that cause a loss of &#60;1 log10eCFU/mL (i.e., &#60;10 CFU/mL). Further studies will determine the proportion of very low burden patients that cause false negative results due to heat inactivation.

A Tuberculosis Molecular Bacterial Load Assay TB-MBLA

We describe a tuberculosis molecular bacterial load assay test performed after heat inactivation of sputum. Heat inactivation renders sputum samples noninfectious and obviates the need for containment level 3 laboratories for tuberculosis molecular tests.

结核病分子细菌负荷测定（TB-MBLA）

Tuberculosis is caused by Mycobacterium tuberculosis (Mtb), a pathogen classified by the United Nations (UN) as a dangerous category B biological ...

Spatial Quantification of Drugs in Pulmonary Tuberculosis Lesions by Laser Capture Microdissection Liquid Chromatography Mass Spectrometry (LCM-LC/MS)

Tuberculosis is still a leading cause of morbidity and mortality worldwide. Improvements to existing drug regimens and the development of novel therapeutics are urgently required. The ability of dosed TB drugs to reach and sterilize bacteria within poorly-vascularized necrotic regions (caseum) of pulmonary granulomas is crucial for successful therapeutic intervention. Effective therapeutic regimens must therefore contain drugs with favorable caseum penetration properties. Current LC/MS methods for quantifying drug levels in biological tissues have limited spatial resolution capabilities, making it difficult to accurately determine absolute drug concentrations within small tissue compartments such as those found within necrotic granulomas. Here we present a protocol combining laser capture microdissection (LCM) of pathologically-distinct tissue regions with LC/MS quantification. This technique provides absolute quantification of drugs within granuloma caseum, surrounding cellular lesion and uninvolved lung tissue and, therefore, accurately determines whether bactericidal concentrations are being achieved. In addition to tuberculosis research, the technique has many potential applications for spatially-resolved quantification of drugs in diseased tissues.

Spatial Quantification of Drugs in Pulmonary Tuberculosis Lesions by Laser Capture Microdissection Liquid Chromatography Mass Spectrometry LCM-LC/MS

Here, we describe a protocol using laser capture microdissection coupled with LC/MS analysis to spatially-quantify drug distributions within pulmonary tuberculosis granulomas. The approach has broad applicability to quantifying drug concentrations within tissues at high spatial detail.

激光捕获显微切割液相色谱质谱 (LCM-LC/MS) 对肺结核患者药物的空间量化

Tuberculosis is still a leading cause of morbidity and mortality worldwide. Improvements to existing drug regimens and the development of novel ...

医学

An Automated Culture System for Use in Preclinical Testing of Host-Directed Therapies for Tuberculosis

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), was the most significant infectious disease killer globally until the advent of COVID-19. Mtb has evolved to persist in its intracellular environment, evade host defenses, and has developed resistance to many anti-tubercular drugs. One approach to solving resistance is identifying existing&#160;approved drugs that will boost the host immune response to Mtb. These drugs could then be repurposed as adjunctive host-directed therapies (HDT) to shorten treatment time and help overcome antibiotic resistance.
Quantification of intracellular Mtb growth in macrophages is a crucial aspect of assessing potential HDT. The gold standard for measuring Mtb growth is counting colony-forming units (CFU) on agar plates. This is a slow, labor-intensive assay that does not lend itself to rapid screening of drugs. In this protocol, an automated, broth-based culture system, which is more commonly used to detect Mtb in clinical specimens, has been adapted for preclinical screening of host-directed therapies. The capacity of the liquid culture assay system to investigate intracellular Mtb growth in macrophages treated with HDT was evaluated. The HDTs tested for their ability to inhibit Mtb growth were all-trans Retinoic acid (AtRA), both in solution and encapsulated in poly(lactic-co-glycolic acid) (PLGA) microparticles and the combination of interferon-gamma and linezolid. The advantages of this automated liquid culture-based technique over the CFU method include simplicity of setup, less labor-intensive preparation, and faster time to results (5-12 days compared to 21 days or more for agar plates).

Rapid and efficient quantification of intracellular M. tuberculosis growth is crucial for pursuing improved therapies against tuberculosis (TB). This protocol describes a broth-based colorimetric detection assay using an automated liquid culture system to quantify Mtb growth in macrophages treated with candidate host-directed therapies.

用于宿主靶向治疗结核病临床前检测的自动化培养系统

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), was the most significant infectious disease killer globally until the advent ...

<meta charset="utf8"></head><body>使用双报告基因的 脓肿分枝 杆菌高通量筛选测定

Assay Development for High-Throughput Drug Screening Against Mycobacteria

Mycobacterium abscessus (Mab) infections are challenging to treat due to high intrinsic drug resistance, comparable to multidrug-resistant tuberculosis. Treatments are extremely ineffective and based on a multi-drug regimen, resulting in low patient compliance. Consequently, the scientific community is urged to identify new and effective drugs to treat these infections. One of the strategies employed to this end is drug repurposing - the process of identifying new therapeutic opportunities for existing drugs in the market, circumventing the time required to establish pharmacokinetic and safety profiles of new drugs. With most studies on drug development against Mab relying on traditional and time-consuming methods, an assay for high-throughput drug screening was developed against mycobacteria using an in house developed double-reporter strain of Mab. Using liquid-handling robotics, automated microscopy, and analysis, alongside in house developed double reporter strains, bacterial viability can be rapidly measured using two different readouts, luminescence and fluorescence, without adding reagents or performing any extra steps. This reduces time and variability between assays, a major advantage for high-throughput screenings. The described protocol was validated by screening a library of 1280 compounds. The obtained results were corroborated by the literature, with efficient detection of active compounds. Thus, this work fulfilled the aim of supplying the field with a new tool to help fight this extremely drug-resistant bacteria.

<meta charset="utf8"></head><body>作者聚焦:用于高效发现 脓肿分枝杆菌 治疗的可扩展药物筛选方案

This study developed an assay for high-throughput screening against Mycobacterium abscessus with a&#160;recently created double reporter strain, using fluorescence and luminescence to assess bacterial viability quickly. This protocol will be relevant for researchers aiming to screen new drugs against this drug-resistant bacteria.

分枝杆菌高通量药物筛选的分析开发

Mycobacterium abscessus (Mab) infections are challenging to treat due to high intrinsic drug resistance, comparable to multidrug-resistant tuberculosis. ...

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此视频中的章节

用于适应高通量/高含量筛查的细胞内分枝杆菌定量的微观表型检测

木炭琼脂刃天青分析的可视化分枝杆菌的半定量，中等吞吐量枚举

系统抑制剂靶向细胞内的疗效和毒性筛选

高通量兼容检测，以评估对巨噬细胞传代药物疗效

结核病分子细菌负荷测定（TB-MBLA）

激光捕获显微切割液相色谱质谱 (LCM-LC/MS) 对肺结核患者药物的空间量化

用于宿主靶向治疗结核病临床前检测的自动化培养系统

分枝杆菌高通量药物筛选的分析开发

分枝杆菌高通量药物筛选的分析开发

分枝杆菌高通量药物筛选的分析开发