Biz reaktif bize sağlamış Yohei Yamauchi ve Roberta Mancini teşekkür ederiz. AH laboratuvar Marie Curie ilk Eğitim Ağları (ITN) tarafından desteklenmiştir, ve İsviçre Ulusal Bilim Vakfı tarafından Avrupa Araştırma Konseyi (ERC) (Sinergia).

Tamponlar ve Stok Çözümleri hazırlanması 1. <ol><li> 80 mi GKD 2 O 470 mg TRIS-hidroklorid, 390 mg MES hidrat ve 580 mg NaCI çözülmesiyle (20 mM MES, 30 mM Tris ve 100 mM NaCl) MNT tamponu hazırlayın PH 7.4 tampon ayarlamak ve GKD 2 O 100 ml&#39;lik bir nihai hacme getirmek </li><li> 80 ml ​​dH 2 O her 9.76 gr MES hidrat çözerek 500 mM MES tamponu üç özdeş çözümler hazırlayın. konsantre NaOH ile titre edilerek, sırasıyla pH 5.8, 5.4 ve 5.0, tamponları ayarlayın. DH 2 O 100 ml&#39;lik nihai hacme kadar her bir tampon getirmek </li><li> DH 2 O 80 ml, her 7.88 gr TRIS-hidroklorid çözülmesiyle 500 mM Tris tamponu, iki özdeş çözüm hazırlanması ve konsantre HCI ile titre edilerek, sırası ile 7.4 ve 6.4, pH ayarlamak. DH 2 O 100 ml&#39;lik nihai hacme kadar tampon getirmek </li><li> DH 2 O% 50 gliserol çözeltisi hazırlayın ve glisin kadar iyice karıştırınerol berrak bir karışım. Bir cam şişe içine Steritop filtre birimi (0.22 um gözenek boyutu) ile çözelti filtre. </li><li> 10% NP-40 çözeltisi ve DH 2 O 1 M NaCl hazırlanması </li><li> 4 ml GKD 2 O. iki tablet çözerek 25x konsantre proteaz inhibitörü hazırlayın </li></ol> Gliserol Gradyanların 2. Hazırlık <ol><li> 5 mi deterjan tamponu ana karışımı hazırlanması (pH 7.4, 6.4, 5.8, 5.4 ve 5.0) test etmek için, her bir pH durumu için çözeltisi (300 mM NaCl,% 2 NP-40, 2 x proteaz inhibitörü konsantre edildi). Bu amaçla, 1 M NaCI 9 mi, 10% NP-40, 6 ml 25x proteaz inhibitörü stokunun 2.4 mi, 9 mi GKD 2 0 karıştırın. </li><li> Her pH koşulu pipet için 50 ml konik tüp içine ana karışımı 4.4 ml. </li><li> pH değerleri 5.8 üzerinde tüp için ilgili pH&#39;ı ayarlanmış 500 mM Tris stok çözeltisi 0.6 ml ekleyin. pH 5.8 ve daha düşük için ilgili pH&#39;ı ayarlanmış 500 mM MES, stok çözeltisi 0.6 ml ekleyin. </li><li> 5 yapmak300 mM NaCl ihtiva eden tampon çözeltisi mi, 2x proteaz inhibitörü, 60 mM Tris pH 7.4, GKD 2 O ayarlandı Bu deterjan içermeyen kontrol degrade tampon olarak görev yapacak. </li><li> Gerekirse, sırasıyla konsantre edildi HCI ve NaOH çözeltileri eklenerek pH 7.4, 6.4, 5.8, 5.4 ve 5.0 için çözeltilerin pH ince ayarlar. </li><li> altı farklı% 25 gliserol Çözeltilerin elde edilen deterjan içeren deterjan içermeyen tampon karışımları, 5 ml% 50 gliserol stokunun 5 ml. pH indikatör şeritleri kullanarak pH değerlerini kontrol edin. Not: ölçülü bir pH istenen değerden önemli ölçüde farklıdır durumda, ilgili çözümleri tekrar hazırlanmalıdır. </li><li> 7 oranında a 3 dH 2 O ile% 50 gliserol stok karıştırılarak% 15 gliserol çözeltisi hazırlayın. </li></ol> IAV 3. Ultrasantrifüj <ol><li> 5 ml&#39;lik bir şırınga ve bir öncesine kullanılarak ultra net santrifüj tüpleri içine (13.2 mi, 14 mm x 89 mm), 3 ml% 15 gliserol solüsyonu ilavedle (9 cm uzunluğunda 21 G). Bu eğim bütünlüğünü bozacağı olarak borunun iç duvarında damla bırakmayın. Altı santrifüj tüpleri test beş pH koşulları her biri için, kontrol örneği için bir toplam için tekrarlayın. </li><li> Dikkatli bir şekilde 5 ml şırınga ve uzun bir iğne kullanılarak% 15 gliserol tabakasının altında 3.4 mL% 25 gliserol çözeltisi yerleştirin. iki kat karıştırmak değil özen gösterin. ilgili pH ayarlı gliserol çözeltileri test etmek altı koşulları için tekrarlayın. NOT: Aşağıdaki adımlar için sınıf II biyogüvenlik kabini içinde çalışmak. </li><li> Yavaşça 1 mi MNT tamponu içinde seyreltilmiş IAV (X31, H3N2) içeren alantoik akışkan açıklık 30 ul gliserol gradyanlar Bindirme her gradient (20-30 ug toplam viral proteinin karşılık gelir). </li><li> Denge tüpleri karşı ve SW41 Ultrasantrifügasyon rotor içine koyun. 55.000 x g&#39;de 150 dakika, ve 12 ° C santrifüj. </li><li> Santrifüj işleminden sonra, dikkatli bir şekildeTemiz bir Pasteur pipeti ve bir aspiratör kullanarak süpernatant, yani hem gliserol katmanlarını kaldırmak. 40 ul (1 x), LDS numune tamponu indirgeyici olmayan pelletini. Tamamen pelet çözülür aşağı birkaç kez pipetleyin ve önemlidir. 1.5 ml mikrosantrifüj tüpü içine örnek aktarmak. </li></ol> Topak bölümleri ve Coomassie boyama 4. SDS-PAGE <ol><li> 10 dakika boyunca 95 ° C &#39;de, tüm numuneler ısıtın. bu, SDS-PAGE ile analiz edilinceye kadar, bu noktada numune -20 ° C&#39;de muhafaza edilebilir. </li><li> Yük bir prekast gradyanı (% 4-12) üzerinde eritildi pellet 20 ul Bis-Tris Mini jeli ve çalışan tampon 1x MOPS SDS içinde 200 V de 1 saat boyunca çalışır. </li><li> GKD 2 O&#39;da% 40 metanol ve% 10 buzlu asetik asit ile sabitleme çözeltisi yapmak </li><li> 1 saat için tespit çözeltisi içinde jel inkübe ve Coomassie solüsyonu yeterli bir hacmi ile 15 cm&#39;lik bir hücre kültür kabı içinde gece boyunca hafifçe lekeOda sıcaklığında çalkalayarak. NOT: boyama çözeltisi buharlaşmasını önlemek için yemek kapatmak için önemlidir. </li><li> GKD 2 O. jel destain Jel arka plan berrak hale gelinceye kadar GKD 2 O her 15-20 dakikada bir değiştirin. Bu bant ölçümü için taranır kadar 4 ° C &#39;de GKD 2 O jel saklayın. </li><li> yüksek çözünürlükte jel tarayın ve protein bandı yoğunluklarının ölçümü için piyasada mevcut veya ısmarlama yazılımı kullanın. İlgili bantları yakın bir bölgeden arka plan sinyalini çıkartın ve (pH 7.4&#39;te) deterjan içermeyen kontrol numunelerine bu değerleri normalize. </li></ol>

<ol>
	<li>Taubenberger, J. K., Kash, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influenza+Virus+Evolution,+Host+Adaptation,+and+Pandemic+Formation.">Influenza Virus Evolution, Host Adaptation, and Pandemic Formation.</a> Cell host &amp; microbe. 7 (6), 440-451 (2010).</li><li>Skehel, J. J., Wiley, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Receptor+binding+and+membrane+fusion+in+virus+entry:+the+influenza+hemagglutinin.">Receptor binding and membrane fusion in virus entry: the influenza hemagglutinin.</a> Annual review of biochemistry. 69, 531-569 (2000).</li><li>de Vries, 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=Dissection+of+the+influenza+a+virus+endocytic+routes+reveals+macropinocytosis+as+an+alternative+entry+pathway.">Dissection of the influenza a virus endocytic routes reveals macropinocytosis as an alternative entry pathway.</a> PLoS pathogens. 7 (3), e1001329 (2011).</li><li>Matlin, K. S., Reggio, H., Helenius, A., Simons, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infectious+entry+pathway+of+influenza+virus+in+a+canine+kidney+cell+line.">Infectious entry pathway of influenza virus in a canine kidney cell line.</a> J Cell Biol. 91 (3 Pt 1), 601-613 (1981).</li><li>Patterson, S., Oxford, J. S., Dourmashkin, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+on+the+mechanism+of+influenza+virus+entry+into+cells.">Studies on the mechanism of influenza virus entry into cells.</a> J Gen Virol. 43 (1), 223-229 (1979).</li><li>Rust, M. J., Lakadamyali, M., Zhang, F., Zhuang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assembly+of+endocytic+machinery+around+individual+influenza+viruses+during+viral+entry.">Assembly of endocytic machinery around individual influenza viruses during viral entry.</a> Nat Struct Mol Biol. 11 (6), 567-573 (2004).</li><li>Sieczkarski, S. B., Whittaker, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissecting+virus+entry+via+endocytosis.">Dissecting virus entry via endocytosis.</a> J Gen Virol. 83 (Pt 7), 1535-1545 (2002).</li><li>Yoshimura, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infectious+Cell+Entry+Mechanism+of+Influenza+Virus.">Infectious Cell Entry Mechanism of Influenza Virus.</a> Journal of Virology. 43 (1), 284-293 (1982).</li><li>White, J., Kartenbeck, J., Helenius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membrane-fusion+activity+of+influenza+virus.">Membrane-fusion activity of influenza virus.</a> Embo Journal. 1 (2), 217-222 (1982).</li><li>Martin, K., Helenius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+transport+of+influenza+virus+ribonucleoproteins:+The+viral+matrix+protein+(M1)+promotes+export+and+inhibits+import.">Nuclear transport of influenza virus ribonucleoproteins: The viral matrix protein (M1) promotes export and inhibits import.</a> Cell. 67 (1), 117-130 (1991).</li><li>Palese, P., Shaw, M. L., Knipe, D. M., Howley, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+47.">Chapter 47.</a> Fields Virology. , 1647-1690 (2006).</li><li>Chou, Y. -. Y., 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=Colocalization+of+Different+Influenza+Viral+RNA+Segments+in+the+Cytoplasm+before+Viral+Budding+as+Shown+by+Single-molecule+Sensitivity+FISH+Analysis.">Colocalization of Different Influenza Viral RNA Segments in the Cytoplasm before Viral Budding as Shown by Single-molecule Sensitivity FISH Analysis.</a> PLoS Pathog. 9 (5), e1003358 (2013).</li><li>Martin, K., Helenius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+of+incoming+influenza+virus+nucleocapsids+into+the+nucleus.">Transport of incoming influenza virus nucleocapsids into the nucleus.</a> Journal of Virology. 65 (1), 232-244 (1991).</li><li>Bui, M., Whittaker, G., Helenius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+M1+protein+and+low+pH+on+nuclear+transport+of+influenza+virus+ribonucleoproteins.">Effect of M1 protein and low pH on nuclear transport of influenza virus ribonucleoproteins.</a> Journal of Virology. 70 (12), 8391-8401 (1996).</li><li>Li, 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=pH-Controlled+Two-Step+Uncoating+of+Influenza+Virus.">pH-Controlled Two-Step Uncoating of Influenza Virus.</a> Biophysical Journal. 106 (7), 1447-1456 (2014).</li><li>Stauffer, 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=Stepwise+priming+by+acidic+pH+and+high+K++is+required+for+efficient+uncoating+of+influenza+A+virus+cores+after+penetration.">Stepwise priming by acidic pH and high K+ is required for efficient uncoating of influenza A virus cores after penetration.</a> Journal of Virology. , (2014).</li><li>Zhirnov, O. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solubilization+of+matrix+protein+M1/M+from+virions+occurs+at+different+pH+for+orthomyxo-+and+paramyxoviruses.">Solubilization of matrix protein M1/M from virions occurs at different pH for orthomyxo- and paramyxoviruses.</a> Virology. 176 (1), 274-279 (1990).</li><li>Banerjee, I., 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=Influenza+A+virus+uses+the+aggresome+processing+machinery+for+host+cell+entry.">Influenza A virus uses the aggresome processing machinery for host cell entry.</a> Science. 346 (6208), 473-477 (2014).</li><li>Huotari, 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=Cullin-3+regulates+late+endosome+maturation.">Cullin-3 regulates late endosome maturation.</a> Proceedings of the National Academy of Sciences. 109 (3), 823-828 (2012).</li><li>Yamauchi, Y., 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=Histone+Deacetylase+8+Is+Required+for+Centrosome+Cohesion+and+Influenza+A+Virus+Entry.">Histone Deacetylase 8 Is Required for Centrosome Cohesion and Influenza A Virus Entry.</a> PLoS Pathog. 7 (10), e1002316 (2011).</li><li>Bachmayer, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+Solubilization+of+Hemagglutinin+and+Neuraminidase+from+Influenza+Viruses.">Selective Solubilization of Hemagglutinin and Neuraminidase from Influenza Viruses.</a> Intervirology. 5 (5), 260-272 (1975).</li><li>Reginster, M., Nermut, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+Characterization+of+Influenza+Virus+Cores.">Preparation and Characterization of Influenza Virus Cores.</a> Journal of General Virology. 31 (2), 211-220 (1976).</li><li>Nermut, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Further+Investigation+on+the+Fine+Structure+of+Influenza+Virus.">Further Investigation on the Fine Structure of Influenza Virus.</a> Journal of General Virology. 17 (3), 317-331 (1972).</li><li>Schulze, I. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structure+of+influenza+virus:+II.+A+model+based+on+the+morphology+and+composition+of+subviral+particles.">The structure of influenza virus: II. A model based on the morphology and composition of subviral particles.</a> Virology. 47 (1), 181-196 (1972).</li><li>Candiano, G., 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=Blue+silver:+A+very+sensitive+colloidal+Coomassie+G-250+staining+for+proteome+analysis.">Blue silver: A very sensitive colloidal Coomassie G-250 staining for proteome analysis.</a> Electrophoresis. 25 (9), 1327-1333 (2004).</li><li>Greber, U. F., Singh, I., Helenius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+virus+uncoating.">Mechanisms of virus uncoating.</a> Trends in microbiology. 2 (2), 52-56 (1994).</li><li>Yamauchi, Y., Helenius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Virus+entry+at+a+glance.">Virus entry at a glance.</a> Journal of Cell Science. 126 (6), 1289-1295 (2013).</li><li>Zhirnov, O. P., Grigoriev, V. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disassembly+of+Influenza+C+Viruses,+Distinct+from+That+of+Influenza+A+and+B+Viruses+Requires+Neutral-Alkaline+pH.">Disassembly of Influenza C Viruses, Distinct from That of Influenza A and B Viruses Requires Neutral-Alkaline pH.</a> Virology. 200 (1), 284-291 (1994).</li></ol>

The authors have nothing to disclose.

Viral kapsidler metastabil makromoleküler kompleksler bulunmaktadır. virionlar montaj virüs genomunun encapsidation ve yoğunlaşmayı gerektirir, enfeksiyon sonraki turda başlanması bu kompakt kapsid yapısının sökülmesi bağlıdır. Virüsler hücresel reseptörler, şaperonlar, proteolitik enzim, motor protein ve helikazlar yanı sıra pH ve iyonik anahtarları 26,27 tarafından sağlanan fiziksel kuvvetler de dahil olmak üzere kılıf kılıfının döngüsü kontrol etmek için çeşitli hücre...

İnfluenza A virüsü (IAV) zarflı bir virüstür ve Ortomiksoviridae ailesine aittir. Bu genler, parça parça, negatif sens, tek iplikçikli bir RNA genomu üzerindeki kodlanır. İnsanlarda, IAV mevsimsel salgın salgınlar meydana solunum yolu enfeksiyonları, nedenleri ve küresel salgın hastalıklar 1 potansiyelini taşımaktadır. Ev sahibi hücre yüzeyi 2 sialik asit artıkları bağlanma üzerine, IAV klatrin bağlı endositoz ve klatrin bağımsız yollar 3-8 ile yerleştirilebilir. Endositik vakuollerde asidik ortam (pH &lt;5.5), viral füzyonu ve geç endosomal zarı 9 sonuçlanır IAV başak glikoprotein hemaglutinin (HA), büyük bir yapısal değişim tetikler. Site o - IAV kapsid kez geç endosomes (LES), bu çekirdeğin içine viral ribonükleoproteinlerin (vRNPs) taşınması ve ardından sitozolde kaplanmamış olan kaçan (burada da viral &quot;çekirdek&quot; olarak anılacaktır)f virüs replikasyonu ve transkripsiyonu 10-13. HA asit aktivasyonu öncesinde virüs ileride bunun demontajı 14-16 çekirdek hazırlar endositik sistemi, pH tedrici bir azalma yaşar. Bu &quot;priming&quot; proton ve K +10,14,16 akını aracılık viral membran M2 iyon kanallarını adım. Virüs iç iyonik konsantrasyon değişim etkileşimleri, viral matriks protein M1 ve sekiz vRNP demet tarafından inşa rahatsız ve membran füzyon 10,14-17 aşağıdaki sitoplazmada IAV olmama kolaylaştırır. hazırlama aşamasında doğrudan ve kantitatif analiz endozomlar deneysel ulaşılması zor olduğu gerçeği engel olmuştur. giriş süreci, dahası, son derece olmayan eşzamanlı olduğunu. Buna ek olarak, bu tür serbest viral RNA veya enfekte ölçümlerinin QRT-PCR gibi son nokta tahlilleri, viral capsi biyokimyasal durumu hakkında detaylı bir resmini sağlamazgiriş herhangi bir aşamasında, d. SiRNA veya ilaç tedavisi ile endozomlardan pertürbasyon anlamlı IAV girişi 18-20 anlayışına katkıda bulunurken, ince ayar sıkı kontrol endosome olgunlaşma programında belirsiz yan etkileri zor ve eğilimli. Bu sorunları önlemek için, hız gradyanı ile santrifüjleme 17 kullanımına dayanmaktadır, daha önce geliştirilmiş in vitro protokol adapte edilmiştir. Çoğunlukla proteolitik bölünme EM analizi ile izlenmiştir deterjan muamelesi kombinasyonları dayanmaktadır diğer girişimlerde 21,22, 23,24, aksine, bu yaklaşım kolayca ölçülebilir bir sonuç sağladı. Farklı gradyan katmanları üzerinden Santrifüj çöktürülmesi parçacıklar maruz bırakılmış ve kontrollü bir şekilde değişen koşullara reaksiyona sağlar. Sunulan protokol olarak, IAV açıklık allantoik akışkan ya da saflaştınlmış viral parçacıkların elde edilen iki tabakalı bir gliserine çöktürülürgradyan olup, buradaki alt tabaka, iyonik olmayan bir deterjan NP-40 (Şekil 1) içerir. Virüs, ikinci deterjan içeren katmanı girdiğinde, viral lipid zarfı ve zarf glikoproteinleri yavaşça çözülmüş ve geride bırakılır. çekirdek, sekiz vRNP demet oluşan ve bir matris tabakasıyla çevrili, pelet fraksiyonu içine kararlı bir yapı olarak çökelleri. M1 ve vRNP ilişkili nükleoprotein (NP) ve viral çekirdek proteinleri, SDS-PAGE ve Coomassie boyama ile pelet içinde tespit edilebilir. Özel olarak, ticari olarak temin edilebilen gradyan jelleri yararlanarak ve son derece hassas Coomassie 25 ile boyama, yüksek hassasiyet ve viral çekirdek ilişkili proteinlerin küçük miktarlarda bile tespitini sağlar. Bu pH, tuz konsantrasyonu ve varsayılan kılıfının faktörler temel bileşenleri ve çekirdek stabil ve sedimantasyon davranışları üzerindeki etkileri gibi farklı koşullar olup olmadığını test etmek için temel ayarlar<html> Sığ. Bu amaç için, gliserol geçişi olarak sadece düşük, deterjan içeren katman faktörü ya da ilgi duyulan durum girerek modifiye edilir. Teknik IAV çekirdek 16 bütünlüğüne pH değerleri ve tuz konsantrasyonları farklı etkisini araştıran özellikle değerli olmuştur. IAV olmama arasında ara adımlar pH 5.5 ve daha düşük 16,17 (Şekil 1) vRNP ayrışma ardından hafif asidik pH&#39;ta (&lt;6.5) matris tabakasının dahil olmak üzere ayrılmasını takip edilebilir. Ikinci adım geç endositik ortamı 16 yansıtan gliserol tabakasında yüksek K + konsantrasyonu varlığında tarafından geliştirilmiştir. Virüs ve çekirdek degrade ile tortulaşmış Böylece, onlar bir değişen ortam endosemelerde taklit koşullar yaşadı. Sonuç hücre biyolojisi deneyleri türetilen sonuçları tamamlayan, in vitro viral çekirdek kademeli sökme oldu. t &quot;&gt; Burada sunulan yöntem, hızlı etkin ve IAV son derece tekrarlanabilir analiz etti (X31 ve A / KAA / 33) ve IBV (B Lee / 40 /) asidik pH ile tetiklenir ve demontaj yanı sıra K +16,17 artan olmama Bu düşünülebilir alkali pH maruz 17 üzerine paramiksovirüs çekirdeklerin. yaklaşım hücre girişi sırasında viral kapsid yapısı ve kapsid sökme biyokimyasal özellikleri içgörü kazanmak için diğer zarflı virüsler adapte edilebilir.

<table border="0" cellpadding="0" cellspacing="0" width="1103">
	
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:391px;">cOmplete&#8482;, EDTA-free protease inhibitor tablets</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:116px;">11873580001</td>
			<td style="width:473px;">The stock solution can be stored at 2 to 8 &#176;C for 1 to 2 weeks</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glacial acetic acid</td>
			<td>Merck Millipore</td>
			<td>100063</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glycerol anhydrous BioChemica</td>
			<td>AppliChem</td>
			<td>A1123</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hydrochloric acid</td>
			<td>Merck Millipore</td>
			<td>100317</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Long injection needle (21 GA, 9 cm, bevel or blunt-end)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MES hydrate</td>
			<td>Sigma-Aldrich</td>
			<td>M8250</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Methanol</td>
			<td>Merck Millipore</td>
			<td>106009</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NP-40</td>
			<td>Sigma-Aldrich</td>
			<td>I8896</td>
			<td>Now commercially available as IGEPAL&#174; CA-630</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NuPAGE&#174; 4-12% Bis-Tris mini gels, 10 wells, 1.0 mm</td>
			<td>Life Technologies</td>
			<td>NP0321</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NuPAGE&#174; LDS sample buffer (4X)</td>
			<td>Life Technologies</td>
			<td>NP0008</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NuPAGE&#174; MOPS SDS running buffer (20X)</td>
			<td>Life Technologies</td>
			<td>NP0001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">pH indicator strips, pH 4.0 - 7.0</td>
			<td>Merck Millipore</td>
			<td>109542</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">QC Colloidal Coomassie Stain</td>
			<td>BIO RAD</td>
			<td>1610803</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium chloride</td>
			<td>Merck Millipore</td>
			<td>106406</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodiumhydroxide</td>
			<td>Merck Millipore</td>
			<td>106498</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Steritop&#8482; filter unit</td>
			<td>Merck Millipore</td>
			<td>SCGPT05RE</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SW41 Ti, ultracentrifuge rotor set</td>
			<td>Beckman Coulter</td>
			<td>331336</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Thinwall, Ultra-clear centrifuge tubes, 13.2 ml, 14 x 89 mm</td>
			<td>Beckman Coulter</td>
			<td>344059</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tris hydrochloride&#160;</td>
			<td>AppliChem</td>
			<td>A1087</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">X31 Influenza A virus (H3N2), egg-grown, clarified allantoic fluid</td>
			<td>Virapur</td>
			<td></td>
			<td>Freshly thawed on 4&#176;C</td>
		</tr>
	</tbody>
</table>

in vitro disassembly of influenza a virus capsids by gradient centrifugation

Acid-triggered molecular processes closely control cell entry of many viruses that enter through the endocytic system. In the case of influenza A virus (IAV), virus fusion with the endosomal membrane as well as the subsequent disassembly of the viral capsid, called uncoating, is governed by the ionic conditions inside endocytic vesicles. The early steps in the virus life cycle are hard to study because endosomes cannot be directly accessed experimentally, creating the need for an in vitro approach. Here, we describe a method based on velocity gradient centrifugation of purified virions through a two-layer glycerol gradient, which enables analysis of the IAV core and its stability. The gradient contains a non-ionic detergent (NP-40) in its lower layer to remove the viral membrane by solubilization as the virus sediments toward the bottom. At neutral pH, viral cores are pelleted as stable structures. The major core components, matrix protein (M1) and the viral ribonucleoproteins (vRNPs), can be clearly identified in the pellet fraction by SDS-PAGE. Decreasing the pH to 6.0 or lower in the bottom layer selectively removes M1 from the pellet followed by release of vRNPs at more acidic conditions. Viral protein bands on Coomassie-stained gels can be subjected to densitometric quantification to monitor intermediate states of IAV disassembly. Besides pH, other factors that influence viral core stability can be assessed, such as salt concentration and putative viral uncoating factors, simply by modifying the detergent-containing glycerol layer accordingly. Taken together, the presented technique allows highly reproducible and quantitative analysis of viral uncoating in vitro. It can be applied to other enveloped viruses that undergo complex uncoating processes.

Daha önce tartışıldığı gibi, endosemelerde priming yetkili olmama IAV çekirdeğini oluşturmak için gereklidir. çekirdeğin protonlanma M1 ve vRNPs etkileşimini zayıflatır (viral RNA, NP oluşan ve polimeraz kompleksi PB1 / PB2 / PA). Gelen virüsü erken endozomlarda (AİS) 6.5 (veya daha düşük) bir pH değerine maruz kalmış ve LES yaklaşık pH 5.0&#39;a virüs sigorta kadar devam eder, bu işlem başlatılır. <p class="jove_content" fo:keep-together.within-page=...

Watch this Scientific Journal Video about In Vitro Disassembly of Influenza A Virus Capsids by Gradient Centrifugation at JoVE.com

In Vitro Disassembly of Influenza A Virus Capsids by Gradient Centrifugation

Disassembly of influenza A virus cores during virus entry into host cells is a multistep process. We describe an in vitro method to analyze the early stages of viral uncoating. In this approach, velocity gradient centrifugation is used to biochemically dissect the steps that initiate uncoating under defined conditions.

Gradient Santrifüj tarafından İnfluenza A Virüsü Kapsidlerin Vitro Demontaj içinde

Acid-triggered molecular processes closely control cell entry of many viruses that enter through the endocytic system. In the case of influenza A virus ...

in-vitro-disassembly-influenza-virus-capsids-gradient

Research

JoVE Journal

Immunology and Infection

In Vitro Disassembly of Influenza A Virus Capsids by Gradient Centrifugation

8.9K Görüntüleme.  ETH Zurich. Disassembly of influenza A virus cores during virus entry into host cells is a multistep process. We describe an in vitro method to analyze the early stages of viral uncoating. In this approach, velocity gradient centrifugation is used to biochemically dissect the steps that initiate uncoating under defined conditions.

Video: In Vitro Disassembly of Influenza A Virus Capsids by Gradient Centrifugation

Generation of Recombinant Influenza Virus from Plasmid DNA

Efforts by a number of influenza research groups have been pivotal in the development and improvement of influenza A virus reverse genetics. Originally established in 1999 1,2 plasmid-based reverse genetic techniques to generate recombinant viruses have revolutionized the influenza research field because specific questions have been answered by genetically engineered, infectious, recombinant influenza viruses. Such studies include virus replication, function of viral proteins, the contribution of specific mutations in viral proteins in viral replication and/or pathogenesis and, also, viral vectors using recombinant influenza viruses expressing foreign proteins 3.

Rescue of influenza A viruses from plasmid DNA is a basic and essential experimental technique that allows influenza researchers to generate recombinant viruses to study multiple aspects in the biology of influenza virus, and to be used as potential vectors or vaccines.

Plazmid DNA Rekombinant Grip Virüsü Üretimi

Efforts by a number of influenza research groups have been pivotal in the development and improvement of influenza A virus reverse genetics. Originally ...

İmmünoloji ve Enfeksiyon

Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice

During the 1918 influenza virus pandemic, which killed approximately 50 million people worldwide, the majority of fatalities were not the result of infection with influenza virus alone. Instead, most individuals are thought to have succumbed to a secondary bacterial infection, predominately caused by the bacterium Streptococcus pneumoniae (the pneumococcus). The synergistic relationship between infections caused by influenza virus and the pneumococcus has subsequently been observed during the 1957 Asian influenza virus pandemic, as well as during seasonal outbreaks of the virus (reviewed in 1, 2). Here, we describe a protocol used to investigate the mechanism(s) that may be involved in increased morbidity as a result of concurrent influenza A virus and S. pneumoniae infection. We have developed an infant murine model to reliably and reproducibly demonstrate the effects of influenza virus infection of mice colonised with S. pneumoniae. Using this protocol, we have provided the first insight into the kinetics of pneumococcal transmission between co-housed, neonatal mice using in vivo imaging 3.

Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice

A concurrent infection with influenza A virus is one of the factors implicated in the induction of invasive pneumococcal disease during asymptomatic Streptococcus pneumoniae carriage. Here we describe a mixed infection method using infant mice to investigate the synergism between these two respiratory pathogens.

Yılları arasında sinerjistik Araştırma Bioluminescent Görüntüleme kullanma Streptococcus pneumoniae Bebek Fare ve İnfluenza A Virüsü

During the 1918 influenza virus pandemic, which killed approximately 50 million people worldwide, the majority of fatalities were not the result of ...

High-throughput Detection Method for Influenza Virus

Influenza virus is a respiratory pathogen that causes a high degree of morbidity and mortality every year in multiple parts of the world. Therefore, precise diagnosis of the infecting strain and rapid high-throughput screening of vast numbers of clinical samples is paramount to control the spread of pandemic infections. Current clinical diagnoses of influenza infections are based on serologic testing, polymerase chain reaction, direct specimen immunofluorescence and cell culture 1,2.
Here, we report the development of a novel diagnostic technique used to detect live influenza viruses. We used the mouse-adapted human A/PR/8/34 (PR8, H1N1) virus 3 to test the efficacy of this technique using MDCK cells 4. MDCK cells (104 or 5 x 103 per well) were cultured in 96- or 384-well plates, infected with PR8 and viral proteins were detected using anti-M2 followed by an IR dye-conjugated secondary antibody. M2 5 and hemagglutinin 1 are two major marker proteins used in many different diagnostic assays. Employing IR-dye-conjugated secondary antibodies minimized the autofluorescence associated with other fluorescent dyes. The use of anti-M2 antibody allowed us to use the antigen-specific fluorescence intensity as a direct metric of viral quantity. To enumerate the fluorescence intensity, we used the LI-COR Odyssey-based IR scanner. This system uses two channel laser-based IR detections to identify fluorophores and differentiate them from background noise. The first channel excites at 680 nm and emits at 700 nm to help quantify the background. The second channel detects fluorophores that excite at 780 nm and emit at 800 nm. Scanning of PR8-infected MDCK cells in the IR scanner indicated a viral titer-dependent bright fluorescence. A positive correlation of fluorescence intensity to virus titer starting from 102-105 PFU could be consistently observed. Minimal but detectable positivity consistently seen with 102-103 PFU PR8 viral titers demonstrated the high sensitivity of the near-IR dyes. The signal-to-noise ratio was determined by comparing the mock-infected or isotype antibody-treated MDCK cells.
Using the fluorescence intensities from 96- or 384-well plate formats, we constructed standard titration curves. In these calculations, the first variable is the viral titer while the second variable is the fluorescence intensity. Therefore, we used the exponential distribution to generate a curve-fit to determine the polynomial relationship between the viral titers and fluorescence intensities. Collectively, we conclude that IR dye-based protein detection system can help diagnose infecting viral strains and precisely enumerate the titer of the infecting pathogens.

This method describes the use of Infrared dye based imaging system for detection of H1N1 in bronchioalveolar lavage (BAL) fluid of infected mice at a high sensitivity. This methodology can be performed in a 96- or 384-well plate, requires &lt;10 &mu;l volume of test material and has the potential for concurrent screening of multiple pathogens.

Gribi için yüksek verimlilik Tespit Yöntemi

Influenza virus is a respiratory pathogen that causes a high degree of morbidity and mortality every year in multiple parts of the world. Therefore, ...

Isolation of Human Monocytes by Double Gradient Centrifugation and Their Differentiation to Macrophages in Teflon-coated Cell Culture Bags

Human macrophages are involved in a plethora of pathologic processes ranging from infectious diseases to cancer. Thus they pose a valuable tool to understand the underlying mechanisms of these diseases. We therefore present a straightforward protocol for the isolation of human monocytes from buffy coats, followed by a differentiation procedure which results in high macrophage yields. The technique relies mostly on commonly available lab equipment and thus provides a cost and time effective way to obtain large quantities of human macrophages. Briefly, buffy coats from healthy blood donors are subjected to a double density gradient centrifugation to harvest monocytes from the peripheral blood. These monocytes are then cultured in fluorinated ethylene propylene (FEP) Teflon-coated cell culture bags in the presence of macrophage colony-stimulating factor (M-CSF). The differentiated macrophages can be easily harvested and used for subsequent studies and functional assays. Important methods for quality control and validation of the isolation and differentiation steps will be highlighted within the protocol. In summary, the protocol described here enables scientists to routinely and reproducibly isolate human macrophages without the need for cost intensive tools. Furthermore, disease models can be studied in a syngeneic human system circumventing the use of murine macrophages.

We present a simple and efficient protocol for the generation of human macrophages. Buffy coats are processed by double density gradient centrifugation and isolated monocytes are then differentiated to macrophages in Teflon-coated cell culture bags. This maximizes macrophage yields and facilitates cell harvesting for subsequent experiments.

İnsan Çift Gradient Santrifüj ile Monositlerinde ve teflon kaplı Hücre Kültürü Çantalar Makrofagların Onların Farklılaşma İzolasyonu

Human macrophages are involved in a plethora of pathologic processes ranging from infectious diseases to cancer. Thus they pose a valuable tool to ...

Influenza Virus Propagation in Embryonated Chicken Eggs

Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous emergence of new influenza virus strains due to mutation and re-assortment complicates the control of the virus and necessitates the permanent development of novel drugs and vaccines. The laboratory-based study of influenza requires a reliable and cost-effective method for the propagation of the virus. Here, a comprehensive protocol is provided for influenza A virus propagation in fertile chicken eggs, which consistently yields high titer viral stocks. In brief, serum pathogen-free (SPF) fertilized chicken eggs are incubated at 37 &#176;C and 55-60% humidity for 10 &#8211; 11 days. Over this period, embryo development can be easily monitored using an egg candler. Virus inoculation is carried out by injection of virus stock into the allantoic cavity using a needle. After 2 days of incubation at 37 &#176;C, the eggs are chilled for at least 4 hr at 4 &#176;C. The eggshell above the air sac and the chorioallantoic membrane are then carefully opened, and the allantoic fluid containing the virus is harvested. The fluid is cleared from debris by centrifugation, aliquoted and transferred to -80 &#176;C for long-term storage. The large amount (5-10 ml of virus-containing fluid per egg) and high virus titer which is usually achieved with this protocol has made the usage of eggs for virus preparation our favorable method, in particular for in vitro studies which require large quantities of virus in which high dosages of the same virus stock are needed.

Fertile chicken eggs are widely used to produce large amounts of human influenza A virus as they provide a convenient and cost-effective system to prove high yields of virus.

Embriyone Tavuk Yumurta Grip Virüsü Yayılım

Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous ...

Co-immunoprecipitation of the Mouse Mx1 Protein with the Influenza A Virus Nucleoprotein

Studying the interaction between proteins is key in understanding their function(s). A very powerful method that is frequently used to study interactions of proteins with other macromolecules in a complex sample is called co-immunoprecipitation. The described co-immunoprecipitation protocol allows to demonstrate and further investigate the interaction between the antiviral myxovirus resistance protein 1 (Mx1) and one of its viral targets, the influenza A virus nucleoprotein (NP). The protocol starts with transfected mammalian cells, but it is also possible to use influenza A virus infected cells as starting material. After cell lysis, the viral NP protein is pulled-down with a specific antibody and the resulting immune-complexes are precipitated with protein G beads. The successful pull-down of NP and the co-immunoprecipitation of the antiviral Mx1 protein are subsequently revealed by western blotting. A prerequisite for successful co-immunoprecipitation of Mx1 with NP is the presence of N-ethylmaleimide (NEM) in the cell lysis buffer. NEM alkylates free thiol groups. Presumably this reaction stabilizes the weak and/or transient NP&#8211;Mx1 interaction by preserving a specific conformation of Mx1, its viral target or an unknown third component. An important limitation of co-immunoprecipitation experiments is the inadvertent pull-down of contaminating proteins, caused by nonspecific binding of proteins to the protein G beads or antibodies. Therefore, it is very important to include control settings to exclude false positive results. The described co-immunoprecipitation protocol can be used to study the interaction of Mx proteins from different vertebrate species with viral proteins, any pair of proteins, or of a protein with other macromolecules. The beneficial role of NEM to stabilize weak and/or transient interactions needs to be tested for each interaction pair individually.

This co-immunoprecipitation protocol allows to study the interaction between the influenza A virus nucleoprotein and the antiviral Mx1 protein in human cells. The protocol emphasizes the importance of N-ethylmaleimide for successful co-immunoprecipitation of Mx1 and influenza A virus nucleoprotein.

İnfluenza A virüsü nükleoproteini Fare MX1 Protein Co-immunopresipitasyonu

Studying the interaction between proteins is key in understanding their function(s). A very powerful method that is frequently used to study interactions ...

Nasal Wipes for Influenza A Virus Detection and Isolation from Swine

Surveillance for influenza A viruses in swine is critical to human and animal health because influenza A virus rapidly evolves in swine populations and new strains are continually emerging. Swine are able to be infected by diverse lineages of influenza A virus making them important hosts for the emergence and maintenance of novel influenza A virus strains. Sampling pigs in diverse settings such as commercial swine farms, agricultural fairs, and live animal markets is important to provide a comprehensive view of currently circulating IAV strains. The current gold-standard ante-mortem sampling technique (i.e. collection of nasal swabs) is labor intensive because it requires physical restraint of the pigs. Nasal wipes involve rubbing a piece of fabric across the snout of the pig with minimal to no restraint of the animal. The nasal wipe procedure is simple to perform and does not require personnel with professional veterinary or animal handling training. While slightly less sensitive than nasal swabs, virus detection and isolation rates are adequate to make nasal wipes a viable alternative for sampling individual pigs when low stress sampling methods are required. The proceeding protocol outlines the steps needed to collect a viable nasal wipe from an individual pig.

The authors present a protocol to collect swine nasal wipes to detect and isolate influenza A viruses.

Domuz influenza A virüs Algılama ve İzolasyonu için Burun Mendil

Surveillance for influenza A viruses in swine is critical to human and animal health because influenza A virus rapidly evolves in swine populations and ...

Measuring Attachment and Internalization of Influenza A Virus in A549 Cells by Flow Cytometry

Attachment to target cells followed by internalization are the very first steps of the life cycle of influenza A virus (IAV). We provide here a detailed protocol for measuring relative changes in the amount of viral particles that attach to A549 cells, a human lung epithelial cell line, as well as in the amount of particles that are internalized into the cell. We use biotinylated virus which can be easily detected following staining with Cy3-labeled streptavidin (STV-Cy3). We describe the growth, purification and biotinylation of A/WSN/33, a widely used IAV laboratory strain. Cold-bound biotinylated IAV particles on A549 cells are stained with STV-Cy3 and measured using flow cytometry. To investigate uptake of viral particles, cold-bound virus is allowed to internalize at 37 &#176;C. In order to differentiate between external and internalized viral particles, a blocking step is applied: Free binding spots on the biotin of attached virus on the cell surface are bound by unlabeled streptavidin (STV). Subsequent cell permeabilization and staining with STV-Cy3 then enables detection of internalized viral particles. We present a calculation to determine the relative amount of internalized virus. This assay is suitable to measure effects of drug-treatments or other manipulations on attachment or internalization of IAV.

We present a protocol describing a semi-quantitative method for measuring both, the attachment of influenza A virus to A549 cells, as well as the internalization of virus particles into the target cells by flow cytometry.

Akış Sitometrisi ile A549 Hücreleri Eklenti ve içselleştirilmesi Gribi bir virüs Ölçme

Attachment to target cells followed by internalization are the very first steps of the life cycle of influenza A virus (IAV). We provide here a detailed ...

Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of inflammation. They are key players in the innate immune system and play major roles in cancer biology. Neutrophils have been proposed as key mediators of malignant transformation, tumor progression, angiogenesis and in the modulation of the antitumor immunity; through their release of soluble factors or their interaction with tumor cells. To characterize the specific functions of neutrophils, a fast and reliable method is coveted for in vitro isolation of neutrophils from human blood. Here, a density gradient separation method is demonstrated to isolate neutrophils as well as mononuclear cells from the blood. The procedure consists of layering the density gradient solution such as Ficoll carefully above the diluted blood obtained from patients diagnosed with chronic lymphocytic leukemia (CLL), followed by centrifugation, isolation of mononuclear layer, separation of neutrophils from RBCsby dextran then lysis of residual erythrocytes. This method has been shown to isolate neutrophils &#8805; 90 % pure. To mimic the tumor microenvironment, 3-dimensional (3D) experiments were performed using basement membrane matrix such as Matrigel. Given the short half-life of neutrophils in vitro, 3D experiments with fresh human neutrophils cannot be performed. For this reason promyelocytic HL60 cells are differentiated along the granulocytic pathway using the differentiation inducers dimethyl sulfoxide (DMSO) and retinoic acid (RA). The aim of our experiments is to study the role of neutrophils on the sensitivity of lymphoma cells to anti-lymphoma agents. However these methods can be generalized to study the interactions of neutrophils or neutrophil-like cells with a large range of cell types in different situations.

Neutrophils are the most abundant type of white blood cells. The isolation of neutrophils from human blood by density gradient separation method and the differentiation of human promyelocytic (HL60) cells along the granulocytic pathway are described here; to test their role on sensitivity of lymphoma cells to anti-lymphoma agents.

Nötrofil İzolasyon ve Analiz Terapötik Ajanların için Lenfoma Hücre Duyarlılık kendi Rolü belirleme

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of ...

Influenza A Virus Studies in a Mouse Model of Infection

Influenza viruses cause over 500,000 deaths worldwide1 and are associated with an annual cost of 12 - 14 billion USD in the United States alone considering direct medical and hospitalization expenses and work absenteeism2. Animal models are crucial in Influenza A virus (IAV) studies to evaluate viral pathogenesis, host-pathogen interactions, immune responses, and the efficacy of current and/or novel vaccine approaches as well as antivirals. Mice are an advantageous small animal model because their immune system is evolutionarily similar to that found in humans, they are available from commercial vendors as genetically identical subjects, there are multiple strains that can be exploited to evaluate the genetic basis of infections, and they are relatively inexpensive and easy to manipulate. To recapitulate IAV infection in humans via the airways, mice are first anesthetized prior to intranasal inoculation with infectious IAVs under proper biosafety containment. After infection, the pathogenesis of IAVs is determined by monitoring daily the morbidity (body weight loss) and mortality (survival) rate. In addition, viral pathogenesis can also be evaluated by assessing virus replication in the upper (nasal mucosa) or lower (lungs) respiratory tract of infected mice. Humoral responses upon IAV infection can be rapidly evaluated by non-invasive bleeding and secondary antibody detection assays aimed at detecting the presence of total or neutralizing antibodies. Here, we describe the common methods used to infect mice intranasally (i.n) with IAV and evaluate pathogenesis, humoral immune responses and protection efficacy.

Influenza A viruses (IAVs) are important human respiratory pathogens. To understand the pathogenicity of IAVs and to perform preclinical testing of novel vaccine approaches, animal models mimicking human physiology are required. Here, we describe techniques to evaluate IAV pathogenesis, humoral responses and vaccine efficacy using a mouse model of infection.