The present study was supported by the NIH grants HL120947 (P.C.), HL103868 (P.C.), and the American Heart Association Grant-in-Aid (P.C.)

Genel sözleri: NOT steril koşullar altında yumurta manipülasyonu ile ilgili tüm prosedürleri uygulayın ve steril tekniği buna göre kullanılmalıdır. % 70 etanol ile tüm ekipman kullanmadan önce ön-temiz. Genel olarak, influenza virüsü aşılama ve hasat BSL-2 laboratuvarda yapılmalıdır. Ancak, bu protokol yaymak için kullanıldığında çok daha patojenik grip virüsleri (örneğin, salgın ve pandemi öncesi suşları, kümes hayvanları ve hayvancılık, yüksek patojen kuş gribi suşları, 1918 H1N1 suşu için bir tehlike teşkil suşları), yüksek biyogüvenlik düzeyleri ve Bazı durumlarda, biyogüvenlik önlemleri ve izinler gereklidir. Yerel Kurumsal Biyogüvenlik Komitesi grip virüsü ile ilgili tüm araştırmaları onaylaması gerekir. Aşılama için Yumurta 1. Hazırlık <ol><li> Uygun bir satıcıdan serum patojen içermeyen (SPF) taze döllenmiş yumurta kuş edinin. Tipik haliyle, tavuk yumurtası kullanılır. Yumurta bizi olmalıhemen girişte ed. </li><li> Otomatik yumurta turner ile nemlendirilmiş yumurta inkübatör varış yeri yumurta düzenli yumurta döndürmek için üzerine. Otomatik yumurta turner mevcut değilse, elle en az 2-3 kez bir gün (eldiven giymek ve mümkün olduğunca steril olarak her şeyi tutmak için emin olun) yumurta döndürün. </li><li> 37 ° C ve 10-11 gün boyunca% 55-60 nemde kuluçkaya. </li></ol> 2. Yumurta Mum <ol><li> Inkübasyon yaklaşık 7 veya 8 gün sonra candling ile infertilite yumurta kontrol etmek için karanlık bir odada bir parlak ışığa karşı yumurta incelemek için bir yumurta Candler kullanın. <ol><li> % 70 etanol ile yumurta Candler silin. Genellikle eldiven değiştirme ve patojenlerin kontaminasyon riskini en aza indirmek için% 70 etanol ile dezenfekte edin. </li><li> Inkübatör yumurta çıkarın ve boş yumurta kartonları koyun. </li><li> Odada ışıkları kapatın. </li><li> Candler karşı bir defada her yumurta bir büyük ucunu tutun. </li><li> Determin için yumurta uyunE o bereketli ya infertil olup olmadığını. NOT: Bir fasulye şeklinde embriyo giden İnce kan damarları açıkça görünür olmalıdır. Döllenmemiş yumurta görünür yumurta sarısı ile küçük bir kan nokta olarak görünecektir. </li></ol></li><li> Döllenmemiş yumurta olan atın ve inkübatör canlı yumurta dönün. Fazla 30 dakika inkübatör dışında yumurta bırakmayın. Bir yumurtanın durumu teyit edilememesi halinde, bunu işaretleyin ve daha sonra gözlemlemek. </li></ol> Virüs İnokulum 3. hazırlanması <ol><li> 10 mM HEPES (pH 7.4) ihtiva eden steril PBS içinde 10 4 pfu / ml - yaklaşık 10 ila 3 grip virüsü stokunu. Kritik adım: kullanımdan hemen önce virüs stokunu ve buz üzerinde her zaman seyreltilmiş virüs tutmak. </li></ol> Alantoik Rota aracılığıyla 4. Grip Virüsü Aşılama <ol><li> Virüs inokülasyonundan (gün 10 ve 11) gün, daha yumurta mum ve herhangi bir ölü embriyolar ortadan kaldırır. Canlı embriyoların ayırtyumurta içinde hareket arıyor. </li><li> Inkübatör üç yumurta çıkarın ve hava kesesi kadar ayrı bir tutucu yumurta düzenlemek. </li><li> Kalıcı bir kalem ile yumurta hava sahasını işaretleyin. </li><li> % 70 etanol ile hava alanı üzerinde eggshell yıkayın. </li><li> Bir yumurta karton ve bir biyogüvenlik kaput (BSL-2) içine hava boşluğu yukarı yumurta koyun. </li><li> Her bir yumurta hava torbasının hemen üzerinde bir kabuk içinde küçük bir delik açmak için bir steril 18G iğne kullanın. Embriyo veya sarısı bıçaklama önlemek için çok derinden iğne eklemek için dikkatli olun. </li><li> Steril 1 ml şırınganın içine seyreltilmiş grip virüsü çizin ve bir 22G iğne takın. </li><li> Dikkatle allantoik boşluğuna 45 ° açıyla iğne ile şırınga ilerlemek. </li><li> Seyreltilmiş grip virüsünün 0.2 ml enjekte edilir. </li><li> Diğer iki yumurta enjeksiyon tekrarlayın ve sonra şırınga ve iğne atın. </li><li> Bir tutkal tabancası (ya da erimiş parafin mumu) den tutkal bir damla ile delik mühür. Be tutkal yumurta içinde sızıntı olmadığını dikkatli. </li><li> Hava alanı yukarı çekti yumurta kuvöz içine yumurta geri yerleştirin. </li><li> Tekrarlayın 4.2 adımları - 4.12 tüm yumurtaları aşılanmış kadar. </li></ol> 5. İnkübasyon Süresi <ol><li> 37 ° C&#39;de ve •% 60 nemde açmadan enfekte yumurta inkübe edin. </li><li> Grip virüsü tipine bağlı olarak optimum inkübasyon süresi seçin. 48 saat boyunca influenza A inkübe; 72 saat grip B ve C kuluçkaya yatmaktadır. </li></ol> 6. Grip Virüsü Hasat <ol><li> İnkübasyon süresinden sonra, embriyo öldürmek ve kan ile enfekte alantoik akışkan kontrol etme riskini azaltmak için kan damarları, 4 saat (ya da O / N), en az 4 ° C &#39;de yumurta soğutun. Verimi azaltır virüs, emici kırmızı kan hücrelerini engellemek için bunu yapın. Seçenek olarak ise, soğuk yumurta, 30 dakika boyunca -20 ° C &#39;de; Bununla birlikte, bu, kan kirlenme riskini arttırır. </li><li> Yumurta yeterince soğutulmuş olmuştur sonra, bir biyogüvenlik kaput yumurta transferi. Hava kesesi yukarı bakacak şekilde bir firma tutucu içine yumurta yerleştirin. % 70 etanol ile yumurta yüzeyini temizleyin. </li><li> Hava kesesi üzerindeki kabuğu açmak için steril makas kullanın. Koryoalantoik zar yok etmek değil dikkat ederek hava kesesi etrafında kabuk çıkarın. </li><li> Steril künt forseps ile koryoalantoik zar açın. Yavaşça embriyo ve küçük bir spatula ya da kaşık ile yumurta sarısı kesesi kenara taşıyın. Sarısını yırtılmasına dikkat edin. </li><li> 1 ml&#39;lik bir Eppendorf pipet yardımıyla, allantoik akışkanın toplanması. Gerekirse, yan biraz kadar sıvı mümkün olduğunca toplamak için yumurta eğin. </li><li> 50 ml&#39;lik plastik konik tüp içine bütün yumurta, allantoik akışkanın birleştirin. Virüs hasat sırasında her zaman buz üzerinde tüpler tutun. Bir yumurta verimi 5 - hafif sarımsı bir sıvı 10 mi. </li><li> 4 ° C&#39;de 10 dakika boyunca 1000 x g&#39;de virüs içeren alantoik akışkan Spin6, C yıkıntıları pelet haline getirildi. Yeni 50 ml tüp içine net sıvıyı aktarın buz tuttu. Bir BSL-2 atık kabına yumurta bertaraf edin. </li></ol> 7. Depolama <ol><li> Hemen allantoik açıklık sıvının (örneğin, 50, 100 veya 500 ul tümbölenler) bölmeyin ve ek-freeze sıvı azot içinde. Dondurulmuş virüs stokları, uzun süreli depolama için -80 ° C dondurucu transfer. </li></ol>

<ol>
	<li>Centers for Disease Control and Prevention (CDC). <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimates+of+deaths+associated+with+seasonal+influenza+---+United+States,+1976-2007.">Estimates of deaths associated with seasonal influenza --- United States, 1976-2007.</a> MMWR. Morbidity and mortality weekly report. 59 (33), 1057-1062 (2010).</li><li>Neumann, G., Noda, T., Kawaoka, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Emergence+and+pandemic+potential+of+swine-origin+H1N1+influenza+virus.">Emergence and pandemic potential of swine-origin H1N1 influenza virus.</a> Nature. 459 (7249), 931-939 (2009).</li><li>Tumpey, T. M., Garcia-Sastre, 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=Pathogenicity+of+Influenza+Viruses+with+Genes+from+the+1918+Pandemic+Virus:+Functional+Roles+of+Alveolar+Macrophages+and+Neutrophils+in+Limiting+Virus+Replication+and+Mortality+in+Mice.">Pathogenicity of Influenza Viruses with Genes from the 1918 Pandemic Virus: Functional Roles of Alveolar Macrophages and Neutrophils in Limiting Virus Replication and Mortality in Mice.</a> J Virol. 79 (23), 14933-14944 (2005).</li><li>Doherty, P. C., Turner, S. J., Webby, R. G., Thomas, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influenza+and+the+challenge+for+immunology.">Influenza and the challenge for immunology.</a> Nat Immu. 7 (5), 449-455 (2006).</li><li>Webster, R. G., Govorkova, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuing+challenges+in+influenza.">Continuing challenges in influenza.</a> Ann N Y Acad Sci. 1323 (1), 115-139 (2014).</li><li>Szretter, K. J., Balish, A. L., Katz, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unit+15G.1+Influenza:+propagation,+quantification,+and+storage.+.">Unit 15G.1 Influenza: propagation, quantification, and storage. .</a> Current protocols in microbiology. , (2006).</li><li>Short, K. R., Kroeze, E. J. B. V., Fouchier, R. A. M., Kuiken, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogenesis+of+influenza-induced+acute+respiratory+distress+syndrome.">Pathogenesis of influenza-induced acute respiratory distress syndrome.</a> Lancet Infect Dis. 14 (4), 57-69 (2014).</li><li>Ito, T., Suzuki, 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=Differences+in+sialic+acid-galactose+linkages+in+the+chicken+egg+amnion+and+allantois+influence+human+influenza+virus+receptor+specificity+and+variant+selection.">Differences in sialic acid-galactose linkages in the chicken egg amnion and allantois influence human influenza virus receptor specificity and variant selection.</a> J Virol. 71 (4), 3357-3362 (1997).</li><li>Robertson, J. S., Nicolson, C., Major, D., Robertson, E. W., Wood, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+amniotic+passage+in+the+egg-adaptation+of+human+influenza+virus+is+revealed+by+haemagglutinin+sequence+analyses.">The role of amniotic passage in the egg-adaptation of human influenza virus is revealed by haemagglutinin sequence analyses.</a> J Gen Virol. 74 (Pt 10), 2047-2051 (1993).</li><li>Gaush, C. R., Smith, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Replication+and+plaque+assay+of+influenza+virus+in+an+established+line+of+canine+kidney+cells).">Replication and plaque assay of influenza virus in an established line of canine kidney cells).</a> Appl Microbiol. 16 (4), 588-594 (1968).</li></ol>

The authors have nothing to disclose.

Grip hastalığının büyük bir küresel yük olur, ve iş akciğer hasarı 7 patogenezi anlayış içine devam ediyor. Bu ölümcül hastalık kolaylaştırdı araştırma, çeşitli yöntemler grip virüsü 6 yaymak için geliştirilmiştir. Burada, biz tavuk yumurtası influenza virüsü üretmek için bir tekniği açıklar. Bu yöntemin avantajı, yüksek oranda tekrarlanabilir olduğunu ve çoğu zaman, in vitro çalışmalar için gerekli olan yüksek titre grip virüsü hisse sen...

Grip A insan sağlığı için büyük bir tehdit olmaya devam ediyor. Büyük bir küresel yük dünya çapında yılda 1 500.000 ölüme kadar neden olan bir yıkıcı solunum hastalığıdır. Grip virüsleri ailesi Orthomyxoviridae olup genomları 1,2, 8 negatif sens, tek iplikçikli RNA taşır. Viral genomun yüksek değişebilirlik (yani, antijenik &quot;sürüklenme&quot;) uzun vadeli bağışıklık engeller. Ayrıca, grip, anti-viral ilaçlar 3 giderek dayanıklıdır. 2009 H1N1 pandemik influenza hastalığının (pandemik suşu anti-viral direnç, gecikmiş aşı üretimi) ile ilgili tüm zorlu konuları vurgulanır. Aşı formülasyonu büyük olasılıkla patojenik influenza suşları 4 (H1N1, H3N2 ve İnfluenza B için birer adet) için Dünya Sağlık Örgütü tarafından her yıl belirlenir. Bu yöntem tahmin grip suşu dayandığındans, patojen suşları bazen yanlış tespit ve aşı etkinliği önemli ölçüde düşer vardır. Ayrıca, yeni grip suşları görünümü pandemik hastalık 2 neden bu koruyucu programları aşmak olabilir. evrensel grip aşısının oluşturulması 5 zor olmuştur. Bu nedenle, araştırma akciğer hasarının patogenezinde anlamak içine devam etmelidir. Tesis laboratuar araştırmaları için, çeşitli yöntemler viral izolasyon ve yayılma 6 geliştirilmiştir. İnsan grip virüsleri, memeli hücre çeşitli substratlar olarak amplifiye edilebilir. Bununla birlikte, büyük miktarlarda üretilmesi yüksek titre virüsleri iyi embriyo haline gelmiş yumurtalardan elde edilmektedir. Aşağıdaki protokol grip için mevcut virüs stoklarından bir virüs yayılımını ve depolama tekniğini açıklar.

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			<td>diluted to 70% using water</td>
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			<td height="42" style="height:42px;width:353px;">glue gun &#34;Ad tech Hi Temp Project Pro&#34;</td>
			<td style="width:225px;">Ad tech, Adhesive Technologies, Inc.</td>
			<td>Model 1105</td>
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			<td height="42" style="height:42px;width:353px;">glue &#34;Ad tech MINI SIZE, Multi Temp&#34;</td>
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			<td>220-34ZIP30</td>
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influenza virus propagation in embryonated chicken eggs

Grip enfeksiyonu yaklaşık 36.000 ölüm ve Amerika Birleşik Devletleri&#39;nde 200.000 &#39;den fazla hastaneye yatış her yıl ile ilişkilidir. Mutasyon ve yeniden çeşitler nedeniyle yeni influenza virüs türlerinin sürekli ortaya çıkması virüsün kontrol komplike ve yeni ilaçların ve aşıların kalıcı geliştirilmesini gerekli kılmaktadır. Grip laboratuar tabanlı çalışma virüsün yayılması için güvenilir ve maliyet-etkin bir yöntem gerektirir. Burada, bir kapsamlı protokol sürekli olarak yüksek titre virüs stokları elde edilir verimli tavuk yumurta influenza A virüs yayılması için sağlanır. 11 gün - Kısaca, serum patojen içermeyen (SPF) döllenmiş tavuk yumurtası 37 ° C ve 10% 55-60 nemde bekletilir. Bu süre içinde, embriyo gelişimi kolaylıkla bir yumurta Candler kullanılarak izlenebilir. Virüs aşı, bir iğne ile allantoik oyuğuna virüs stokunun püskürtülmesiyle gerçekleştirilir. 37 ° C&#39;de inkübasyon 2 gün sonra yumurta4 ° C&#39;de en az 4 saat süre ile donduruldu. Hava kesesi ve chorioallantoic membran üzerinde yumurta kabuğu sonra dikkatlice açılır, ve virüs içeren allantoik sıvı hasat edilir. sıvı, santrifüj ile etrafı temizlenmiş alikotlandı ve uzun süreli depolama için -80 ° C&#39;ye kadar aktarılır. büyük miktarda, genellikle, bu protokol ile elde edilir ve yüksek virüs titresi (bir virüs içeren yumurta başına sıvının 5-10 mi) büyük miktarlarda ihtiyaç in vitro çalışmalar için, özellikle, virüs preparatı eden uygun bir yöntem için yumurta kullanımını yapmıştır virüs içinde, aynı virüs stokunun yüksek dozlar gereklidir.

Çeşitli yöntemlerle grip virüsü titre edilmesi için geliştirilmiştir. Uygun bir yöntem seçerek Bir göz bazı canlı viryonlarını değerlendirecek olan, ne olursa olsun başkalarının enfekte dayalı ise canlılığı (örneğin, hemaglutinin deneyi) toplam parçacıkları tespit olduğunu (örneğin, plak deneyi) 6. Burada, bir fare adapte influenza virüsü (A / PR / 8/34) ile aşılanır tavuk yumurtalarından elde alantoik akışkan viral titresi plak deneyi (Şekil ...

Watch this Scientific Journal Video about Influenza Virus Propagation in Embryonated Chicken Eggs at JoVE.com

Influenza Virus Propagation in Embryonated Chicken Eggs

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 ...

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Immunology and Infection

42.6K Görüntüleme.  Cedars-Sinai Medical Center. 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.

Video: Influenza Virus Propagation in Embryonated Chicken Eggs

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

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, ...

Affinity Purification of Influenza Virus Ribonucleoprotein Complexes from the Chromatin of Infected Cells

Like all negative-strand RNA viruses, the genome of influenza viruses is packaged in the form of viral ribonucleoprotein complexes (vRNP), in which the single-stranded genome is encapsidated by the nucleoprotein (NP), and associated with the trimeric polymerase complex consisting of the PA, PB1, and PB2 subunits. However, in contrast to most RNA viruses, influenza viruses perform viral RNA synthesis in the nuclei of infected cells. Interestingly, viral mRNA synthesis uses cellular pre-mRNAs as primers, and it has been proposed that this process takes place on chromatin1. Interactions between the viral polymerase and the host RNA polymerase II, as well as between NP and host nucleosomes have also been characterized1,2.
Recently, the generation of recombinant influenza viruses encoding a One-Strep-Tag genetically fused to the C-terminus of the PB2 subunit of the viral polymerase (rWSN-PB2-Strep3) has been described. These recombinant viruses allow the purification of PB2-containing complexes, including vRNPs, from infected cells. To obtain purified vRNPs, cell cultures are infected, and vRNPs are affinity purified from lysates derived from these cells. However, the lysis procedures used to date have been based on one-step detergent lysis, which, despite the presence of a general nuclease, often extract chromatin-bound material only inefficiently. 
Our preliminary work suggested that a large portion of nuclear vRNPs were not extracted during traditional cell lysis, and therefore could not be affinity purified. To increase this extraction efficiency, and to separate chromatin-bound from non-chromatin-bound nuclear vRNPs, we adapted a step-wise subcellular extraction protocol to influenza virus-infected cells. Briefly, this procedure first separates the nuclei from the cell and then extracts soluble nuclear proteins (here termed the "nucleoplasmic" fraction). The remaining insoluble nuclear material is then digested with Benzonase, an unspecific DNA/RNA nuclease, followed by two salt extraction steps: first using 150 mM NaCl (termed "ch150"), then 500 mM NaCl ("ch500") (Fig. 1). These salt extraction steps were chosen based on our observation that 500 mM NaCl was sufficient to solubilize over 85% of nuclear vRNPs yet still allow binding of tagged vRNPs to the affinity matrix.
After subcellular fractionation of infected cells, it is possible to affinity purify PB2-tagged vRNPs from each individual fraction and analyze their protein and RNA components using Western Blot and primer extension, respectively. Recently, we utilized this method to discover that vRNP export complexes form during late points after infection on the chromatin fraction extracted with 500 mM NaCl (ch500)3.

Influenza viruses replicate their RNA genome in association with host-cell chromatin. Here, we present a method to purify intact viral ribonucleoprotein complexes from the chromatin of infected cells. Purified viral complexes can be analyzed by both Western blot and primer extension of protein and RNA content, respectively.

Enfekte Hücre Kromatin gelen Gribi ribonükleoprotein Komplekslerinin Affinity Arıtma

Like all negative-strand RNA viruses, the genome of influenza viruses is packaged in the form of viral ribonucleoprotein complexes (vRNP), in which the ...

Propagation of Homalodisca coagulata virus-01 via Homalodisca vitripennis Cell Culture

The glassy-winged sharpshooter (Homalodisca vitripennis) is a highly vagile and polyphagous insect found throughout the southwestern United States. These insects are the predominant vectors of Xylella fastidiosa (X. fastidiosa), a xylem-limited bacterium that is the causal agent of Pierce&#39;s disease (PD) of grapevine. Pierce&#8217;s disease is economically damaging; thus, H. vitripennis have become a target for pathogen management strategies. A dicistrovirus identified as Homalodisca coagulata virus-01 (HoCV-01) has been associated with an increased mortality in H. vitripennis populations. Because a host cell is required for HoCV-01 replication, cell culture provides a uniform environment for targeted replication that is logistically and economically valuable for biopesticide production. In this study, a system for large-scale propagation of H. vitripennis cells via tissue culture was developed, providing a viral replication mechanism. HoCV-01 was extracted from whole body insects and used to inoculate cultured H. vitripennis cells at varying levels. The culture medium was removed every 24 hr for 168 hr, RNA extracted and analyzed with qRT-PCR. Cells were stained with trypan blue and counted to quantify cell survivability using light microscopy. Whole virus particles were extracted up to 96 hr after infection, which was the time point determined to be before total cell culture collapse occurred. Cells were also subjected to fluorescent staining and viewed using confocal microscopy to investigate viral activity on F-actin attachment and nuclei integrity. The conclusion of this study is that H. vitripennis cells are capable of being cultured and used for mass production of HoCV-01 at a suitable level to allow production of a biopesticide.

Propagation of Homalodisca coagulata virus-01 via Homalodisca vitripennis Cell Culture

Here we present a protocol to propagate Homalodisca vitripennis cells and HoCV-1 in vitro. Medium was removed from HoCV-1 positive cultures and RNA extracted every 24 hr for 168 hr. Cell survivability was quantified by trypan blue staining. Whole virus particles were extracted post-infection. Extracted RNA was quantified by qRT-PCR.

Yayılması<em&gt; Homalodisca coagulata virüs 01</em&gt; Yoluyla<em&gt; Homalodisca vitripennis</em&gt; Hücre Kültürü

The glassy-winged sharpshooter (Homalodisca vitripennis) is a highly vagile and polyphagous insect found throughout the southwestern United States. These ...

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 ...

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.

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 ...

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.