Forschung auf Influenza-Virus im LM-S Labor wird teilweise von The New York Influenza Center of Excellence (GEMON), ein Mitglied des NIAID Centers of Excellence für Influenza-Forschung und Überwachung (CEIRS) finanziert. Wir danken für ihre Unterstützung bei der Korrektur des Manuskripts Wendy Bates.

<ol>
	<li>Girard, M. P., Cherian, T., Pervikov, Y., Kieny, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+vaccine+research+and+development:+human+acute+respiratory+infections.">A review of vaccine research and development: human acute respiratory infections.</a> Vaccine. 23 (50), 5708-5724 (2005).</li><li>Arnold, S., Monto, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+and+Virology+of+Influenza+Illness.">Epidemiology and Virology of Influenza Illness.</a> Am J Manag Care. 6, 255-264 (2000).</li><li>Palese, P., Shaw, M. L., Knipe, D. M., Howley, P. M., Griffin, D. E., Lamb, R. A., Martin, M. 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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=Genesis+of+a+highly+pathogenic+and+potentially+pandemic+H5N1+influenza+virus+in+eastern+Asia.">Genesis of a highly pathogenic and potentially pandemic H5N1 influenza virus in eastern Asia.</a> Nature. 430 (6996), 209-213 (2004).</li><li>Nogales, A., Martinez-Sobrido, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reverse+Genetics+Approaches+for+the+Development+of+Influenza+Vaccines.">Reverse Genetics Approaches for the Development of Influenza Vaccines.</a> Int J Mol Sci. 18 (20), (2017).</li><li>Kunisaki, K. M., Janoff, E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influenza+in+immunosuppressed+populations:+a+review+of+infection+frequency,+morbidity,+mortality,+and+vaccine+responses.">Influenza in immunosuppressed populations: a review of infection frequency, morbidity, mortality, and vaccine responses.</a> Lancet Infect Dis. 9 (8), 493-504 (2009).</li><li>Belshe, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+attenuated+versus+inactivated+influenza+vaccine+in+infants+and+young+children.">Live attenuated versus inactivated influenza vaccine in infants and young children.</a> N Engl J Med. 356 (7), 685-696 (2007).</li><li>Cox, A., Baker, S. F., Nogales, A., Martinez-Sobrido, L., Dewhurst, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+mouse-adapted+live+attenuated+influenza+virus+that+permits+in+vivo+analysis+of+enhancements+to+the+safety+of+live+attenuated+influenza+virus+vaccine.">Development of a mouse-adapted live attenuated influenza virus that permits in vivo analysis of enhancements to the safety of live attenuated influenza virus vaccine.</a> J Virol. 89 (6), 3421-3426 (2015).</li><li>Nogales, 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=Influenza+A+Virus+Attenuation+by+Codon+Deoptimization+of+the+NS+Gene+for+Vaccine+Development.">Influenza A Virus Attenuation by Codon Deoptimization of the NS Gene for Vaccine Development.</a> J Virol. 88 (18), 10525-10540 (2014).</li><li>Nogales, A., DeDiego, M. 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F., Martinez-Sobrido, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Replication-competent+influenza+A+viruses+expressing+a+red+fluorescent+protein.">Replication-competent influenza A viruses expressing a red fluorescent protein.</a> Virology. 476C, 206-216 (2014).</li><li>Margine, I., Krammer, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+Models+for+Influenza+Viruses:+Implications+for+Universal+Vaccine+Development.">Animal Models for Influenza Viruses: Implications for Universal Vaccine Development.</a> Pathogens. 3 (4), 845-874 (2014).</li><li>Bouvier, N., Lowen, A. 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Die Maus-Modell der IAV ist für in Vivo Studien der IAV Pathogenese, Immunogenität und Schutz Wirksamkeit verbreitet. Die geringe Größe von Mäusen macht sie leicht zu bearbeiten und speichern im Vergleich zu anderen Tiermodellen wie Frettchen oder Meerschweinchen. Darüber hinaus erlauben die Leichtigkeit in Bezug auf Tier Kosten, Gehäuse und Reproduktion ihre Verwendung in präklinischen Impfung-Tests in denen großen Anzahl von Tieren erforderlich sind. Vor allem, da Mäuse verwendet wurden mehrere Forschung Disziplinen, mehrere molekulare und Immunologie murinen Reagenzien stehen zur Verfügung, deren Verwendung für IAV Studien zu erleichtern. Darüber hinaus präsentieren die minimale Host Variabilität und das Vorhandensein des immunen Systems, das evolutionär ähnlich ist Menschen machen sie eine robuste kleine Tiermodell für IAV Studien. Schließlich sind die Untersuchung der Host-virales Protein-Interaktionen und ihren Beitrag zur virale Pathogenese derzeit Machbaren durch den Zugriff auf KO-Mäusen. Neben einige Vorteile der Verwendung von Mäusen für IAV Studien, sind sie jedoch nicht nützlich für Untersuchungen zur Übertragung der IAV. Frettchen oder Meerschweinchen sind daher geeigneter Tiermodelle, IAV Übertragung zu studieren. Klinische Symptome bei Mäusen mit IAV infiziert in der Regel erscheinen 2 bis 3 Tage nach der Infektion, obwohl dies je nach der Maus Alter, Immunstatus, Geschlecht, genetische Hintergrund und Belastung variieren; virale Belastung sowie verwendete Dosis. Die Symptome umfassen Anorexie, Lethargie, kauern, gekräuselte Fell, Verlust der Körper Gewicht und Tod16,17.
In diesem Manuskript beschreiben wir wie bewerten virale Pathogenese in Mäusen infiziert i.n. mit IAV durch die Überwachung der Körper Gewichtsverlust (Morbidität), Prozentsatz des Überlebens (Mortalität) und durch die Bewertung der Virusreplikation in der oberen (Nasenschleimhaut) und senken (Lunge) Atemwege (Abbildung 1 und Abbildung 2). Die Pathogenese der IAV ist ein sehr wichtiger Parameter, nicht nur im Zusammenhang mit der neuen IAV Stämme, sondern auch bei der sicheren Umsetzung der LAIV Impfstoffkandidaten (Abbildung 3). Saisonale IAVs und IAVs, die andere Säugetiere (wie Pferde, Hunde oder Schweine) infizieren produzieren nicht in der Regel Anzeichen einer Krankheit bei Mäusen11,27. In diesem Fall ist die Analyse der viralen Titer in der Lunge oder Nasenschleimhaut von infizierten Mäusen die Hauptparameter, virale Pathogenese der IAV-Stämme zu bewerten. Sobald die Lunge und die Nasenschleimhaut gesammelt, sie sind homogenisiert und die Menge an Viren in diesen Organen durch Plaque-Assay, Immunfluoreszenz-Assay analysiert werden kann, Gewebekultur infektiöse Dosis 50 (TCID50) oder eine andere validierte Methode8 ,29. Es wird empfohlen, Bewertung von viralen Titer über indirekte Immunfluoreszenz, da die Plaque-Assay eine größere Menge an MDCK Zellen (6-Well-Plattenformat erfordert) und, wie der TCID50und mehr Zeit (3-4 Tage) erforderlich ist, um virale Titer zu berechnen. Allerdings um die indirekte Immunfluoreszenz-Assay durchzuführen, ist es notwendig, zu haben: 1) primäre spezifische Antikörper gegen ein IAV-Protein (es empfiehlt sich, einen Antikörper gegen die IAV Nucleoprotein, NP, zu verwenden, da es die häufigste virale Protein produziert wird während der viralen Infektion); (2) sekundäre Antikörper konjugiert zu einem Fluorophor; und 3) ein Fluoreszenzmikroskop, fluoreszierende positivere infizierte Zellen zu zählen.
Da das Immunsystem von Mäusen evolutionär, das Immunsystem des Menschen16 ähnelt und Mäusen eine starke und schützende humorale Antwort gegen IAV Infektionen hervorrufen können, kann die Immunogenität von IAVs (oder Impfstoffkandidaten) bewertet durch die Bestimmung insgesamt (ELISA; Abbildung 4) und neutralisieren (HAI, Abbildung 5) oder Antikörperantworten VNA (Abbildung 6). Um die humoralen Reaktionen nach Immunisierung zu analysieren, können Mäuse durch verschiedene anerkannte Methoden wie Retro-Orbital Punktion, Tail Clip, Stammvenen Punktion oder mandibulären Punktion entlüftet werden. Wir entschieden uns für die submandibulären Punktion Technik26 , weil das Verfahren nicht die Verwendung der Anästhesie erfordert und ermöglicht es uns, einen akzeptablen Volumen des Blutes für immunologische Studien zu erhalten; im Gegensatz zu den Retro-Orbital-Punktion ist wo das Blutvolumen in der Regel wiederhergestellt wo Mäuse betäubt werden sollte, und mit der Rute Clip oder Stammvenen Punktion, gering.
In dieser Handschrift beschrieben, wie das Vorhandensein von Antikörpern gegen insgesamt virale Proteine von ELISA mit Virus infiziert Zellextrakte bewerten. Da IAV Infektion induziert eine schützende Immunität vermittelt, vor allem durch Antikörper gegen das virale HA (die wichtigsten Antigene viral-Ziel), empfiehlt es zu beurteilen, die Menge an spezifischen Antikörpern gegen HA durch ELISA mit rekombinanten gereinigten HA induziert Proteine-10. Um das Vorhandensein von neutralisierenden Antikörpern zu analysieren, HAI und VNA Methoden werden akzeptiert, aber beide haben vor- und Nachteile. Der HAI ist schnell (ca. 2-3 h) und genehmigt durch das Center for Disease und Control (CDC), das Vorhandensein von IAV neutralisierende Antikörper30zu bewerten. Die VNA ist mehr Zeit in Anspruch nehmen (ca. 3-4 Tage) aber ist genauer, da es nur Antikörper bewertet, die Virusinfektion neutralisieren kann. Vor allem die VNA nachweislich Stiel-reaktives neutralisierende Antikörper31sowie NA neutralisierende Antikörper32HA zu erkennen. Ein weiterer Vorteil der VNA ist der Assay-Empfindlichkeit, da weniger IAV (200 FFU) braucht man im Vergleich zu den HAU-Assay, der ca. 10 ~4-105 FFU erfordert. Darüber hinaus kann der HAI-Test zur Erkennung von neutralisierenden Antikörpern gegen Vogelgrippe IAVs aufgrund von Schwierigkeiten mit der Interpretation der Ergebnisse33,34,35problematisch sein. Darüber hinaus erfordert VNA nicht die Verwendung von Erythrozyten zur Identifizierung von neutralisierenden Antikörpern Influenza.
Schließlich beschreiben wir die experimentellen Verfahren um die drei wichtigsten Aspekte zu bewerten, die bei der Entwicklung neuer Impfstoffe IAV (Abbildung 3) berücksichtigt werden müssen: 1) Sicherheit: die Impfung muss sicher und nicht produzieren Krankheit; (2) Immunogenität: der Impfstoff muss immunogen und induzieren humorale und zelluläre schützende Antworten; (3) Schutz Wirksamkeit: der Impfstoff muss Schutz vor Herausforderung mit WT homologe und heterologe Viren induzieren. Die Maus-Modell ist eine gute Wahl für das erste screening eines neuen IAV Impfstoff in Vivo , weil es diverse Impfung Systeme bewerten kann und Bedingungen, einschließlich verschiedene Adjuvantien, Antigen/Impfdosis, Verwaltung und umfassenden Schutz verwenden gegen die Herausforderung mit Homologen oder heterologe IAVs Stämme16,17. Jedoch sollten Impfstoffkandidaten bevor Sie fortfahren zu klinischen Studien am Menschen, zumindest in einem zweiten in Vivo Modell getestet werden.

IAVs sind behüllte Viren in der Orthomyxoviridae Familie3eingestuft. Sie enthalten acht einsträngige RNA-Moleküle mit negativer Polarität3. Beim Menschen verursachen IAVs saisonal Epidemien und gelegentliche Pandemien wichtige Konsequenz, wenn neuartige Viren in der menschlichen Bevölkerung4eingeführt werden. Darüber hinaus werden saisonale IAVs hoch und schnell von Mensch zu Mensch produziert eine erhöhte wirtschaftliche Verluste weltweit jedes Jahr2,5übertragen. IAV Symptome sind Husten, verstopfte Nase, Fieber, Unwohlsein, Kopfschmerzen, Magersucht und Muskelschmerzen, aber das Virus kann auch eine schwere Krankheit bei immungeschwächten Patienten6produzieren. In der Tat, rechnet die World Health Organisation (WHO) vor, dass saisonale Influenza-Viren 300.000-500.000 Todesfälle weltweit pro Jahr1 verursachen. Es gibt nur zwei Arten von Medikamenten, die derzeit von der Food and Drug Administration (FDA) für Influenza-Prophylaxe und Therapie beim Menschen zugelassen: Neuraminidasehemmer (NA) (z.B. Oseltamivir) und Blocker des Ionenkanals M2 (z.B. Amantadin); die Entstehung von resistenten Viren-Varianten ist jedoch eine zunehmende Besorgnis. Impfung, bleibt daher die beste medizinische Möglichkeit, Menschen gegen IAVs Infektionen zu schützen. Bisher wurden drei Arten von Influenza Impfstoffe zugelassen von der FDA für den menschlichen Gebrauch zur Verfügung: rekombinante virale Hämagglutinin (HA) Protein Impfstoffe, inaktivierten Influenza-Impfstoffe (IIV) und live-gedämpft Influenza-Impfstoffe (LAIV)5, 7. die drei Impfstoffe sind entworfen, um gegen das virale HA-Protein, das große Ziel von neutralisierenden Antikörpern gegen IAVs adaptive Immunantwort zu induzieren.
Eine validierte Mausmodell IAV Infektion in Vivo zu studieren
Tiermodelle wurden verwendet, um, unter anderem IAV Pathogenese8,9,10,11, virale Faktoren zu untersuchen, die zu Krankheit12 und/oder viralen Übertragung13 beitragen ,14, und testen Sie die Wirksamkeit der neuen Impfstoffe oder antivirale Medikamente9,10,15. Mäuse (Mus Musculus) sind die am häufigsten verwendeten Tiermodell für IAV Forschung aus mehreren Gründen: 1) das Immunsystem ist evolutionär ähnlich präsentieren, beim Menschen; (2) low-cost, einschließlich Tier Kauf, Gehäuse und Reproduktion; (3) kleine Größe zu bearbeiten und zu speichern; (4) minimal Host Variabilität, homogene Antworten und Ergebnisse zu erhalten; (5) eine große Kenntnis der Mäuse Biologie, einschließlich Genomsequenz; (6) viele verfügbare Molekularbiologie bzw. Immunologie Reagenzien; (7) zur Verfügung Knock-out Mäuse (KO), den Beitrag eines bestimmten Host-Proteins auf virale Infektion zu studieren; und 8) mehrere Maus-Stämmen, die ausgenutzt werden können, um die genetischen Grundlagen von Infektionen zu bewerten.
Es gibt verschiedene Mausstämme derzeit für IAV in Vivozu studieren. Alter, Immunstatus, Geschlecht, genetische Hintergrund und Maus Belastung sowie Routen der Infektion, Dosis und Virenstämme Einfluss auf den Ausgang der IAV-Infektion bei Mäusen. Die am häufigsten verwendeten Mausstämme IAV Forschung verwendeten sind C57BL/6, BALB/C und, in jüngerer DBA.2 Mäuse, da sie anfälliger für IAV Krankheit als die beiden ehemaligen Stämme16,17,18, sind 19 , 20. wichtiger ist, die Immunantwort auch können abweichen, je nach der Maus Belastung18,19,20. Daher ist es sehr wichtig, um alle verfügbaren Informationen über die Maus und die IAV Sorte wählen Sie die beste Option für das Experiment durchgeführt werden zu erholen.
Obwohl die Maus eine gute Tiermodell Infektionsrisiko für in Vivo Studien mit IAV ist, haben sie mehrere Einschränkungen, die in der experimentellen Gestaltung berücksichtigt werden müssen. Zum Beispiel ist eine große Einschränkung der Verwendung von Mäusen für in Vivo Studien, dass IAVs nicht unter Mäuse übertragen. So, für die Übertragung Studien, akzeptiert Tiermodelle (z.B.Frettchen oder Meerschweinchen) sind gebrauchte16,17,21. Darüber hinaus gibt es einige Unterschiede zwischen den Manifestationen der IAV bei Mäusen und Menschen. Im Gegensatz zum Menschen entwickeln Mäuse nicht Fieber bei IAV Infektion; im Gegensatz dazu präsentieren sie mit Hypothermie16,17. Bei Mäusen konzentriert sich IAV Replikation in den unteren Atemwegen (Lunge) anstatt der oberen Atemwege. So korreliert Virulenz der IAV in Mäusen nicht immer in Menschen gesehen. Insgesamt, weil die Vorteile der begrenzten Nachteile überwiegen, stellt Maus erste Tiermodell verwendet, um virale Pathogenese der Grippe, Immunogenität und Schutzwirkung im Impfstoff und antivirale Studien bewerten. Darüber hinaus wäre es nicht vertretbar, Studien mit IAV mit großen Tiermodellen ohne vorherigen Nachweis in einer kleinen Tiermodell der IAV-Infektion. In dieser Handschrift die, wir beschreiben, wie Mäuse intranasal infiziert (i.n.) mit IAV, wie der Schweregrad und Fortschritten der viralen Infektion und zur Durchführung der Experimente erforderlich, um die humorale Immunantwort und Schutz Wirksamkeit bewertet.

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	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:295px;">Madin-Darby Canine Kidney (MDCK) epithelial cells</td>
			<td style="width:119px;">ATCC</td>
			<td style="width:123px;">CCL-34</td>
			<td style="width:121px;"></td>
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		<tr height="40">
			<td height="40" style="height:40px;width:295px;">Six- to eight-week-old female C57BL/6 mice</td>
			<td style="width:119px;">National Cancer Institute (NCI)</td>
			<td>01XBE</td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Turckey red blod cells</td>
			<td style="width:119px;">Biolink Inc</td>
			<td style="width:123px;"></td>
			<td style="width:121px;">Store at 4&#176;C</td>
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			<td height="20" style="height:20px;width:295px;">Dulbecco&#8217;s modified Eagle&#8217;s medium (DMEM)</td>
			<td style="width:119px;">Corning Cellgro</td>
			<td style="width:123px;">15-013-CV</td>
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			<td height="20" style="height:20px;width:295px;">Penicillin/Streptomycin (PS) 100X</td>
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			<td height="20" style="height:20px;width:295px;">Bovin Albumin solution (BA)</td>
			<td style="width:119px;">Sigma-Aldrich</td>
			<td style="width:123px;">A7409</td>
			<td style="width:121px;">Store at 4&#176;C</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Bovin Serum Albumin (BSA)</td>
			<td style="width:119px;">Sigma-Aldrich</td>
			<td style="width:123px;">A9647</td>
			<td style="width:121px;">Store at 4&#176;C</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:295px;">Tosylsulfonyl phenylalanyl chloromethyl ketone (TPCK)-treated trypsin</td>
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			<td style="width:123px;">T8802</td>
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			<td height="20" style="height:20px;width:295px;">Neutral Buffered Formalin 10%</td>
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			<td height="20" style="height:20px;width:295px;">Triton X-100</td>
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			<td style="width:121px;">Store at RT</td>
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			<td height="40" style="height:40px;width:295px;">Monoclonal Antibody anti-NP Influenza A Virus HB-65</td>
			<td style="width:119px;">ATTC</td>
			<td style="width:123px;">H16-L10-4R5</td>
			<td style="width:121px;">Store at -20&#176;C</td>
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			<td height="40" style="height:40px;width:295px;">Polyclonal rabbit anti-mouse immunoglobulins/FITC</td>
			<td style="width:119px;">Dako</td>
			<td style="width:123px;">F0261</td>
			<td style="width:121px;">Store at 4&#176;C</td>
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			<td height="43" style="height:43px;width:295px;">ECL Anti-mouse IgG, Horseradish Peroxidase linked whole antibody</td>
			<td style="width:119px;">GE Healthcare</td>
			<td style="width:123px;">LNA931V/AG</td>
			<td style="width:121px;">Store at 4&#176;C</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:295px;">TMB substrate set</td>
			<td style="width:119px;">BioLegend</td>
			<td style="width:123px;">421101</td>
			<td style="width:121px;">Store at 4&#176;C</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:295px;">Vmax Kinetic plate reader</td>
			<td style="width:119px;">Molecular Devices</td>
			<td style="width:123px;"></td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Dounce Tissue Grinders</td>
			<td style="width:119px;">Thomas Scientific</td>
			<td style="width:123px;">7722-7</td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Receptor destroying enzyme, RDE (II)</td>
			<td style="width:119px;">Denka Seiken Co.</td>
			<td style="width:123px;">370013</td>
			<td style="width:121px;">Store at -20&#176;C</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Crystal Violet</td>
			<td style="width:119px;">Fisher Scienctific</td>
			<td style="width:123px;">C581-100</td>
			<td style="width:121px;">Store at RT</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:295px;">96-well Cell Culture Plate</td>
			<td style="width:119px;">Greiner Bio-one</td>
			<td style="width:123px;">655-180</td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Cell Culture dishes 100mm</td>
			<td style="width:119px;">Greiner Bio-one</td>
			<td style="width:123px;">664-160</td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:295px;">Nunc MicroWell 96-Well Microplates</td>
			<td style="width:119px;">Thermo Fisher Scienctific</td>
			<td style="width:123px;">269620</td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:295px;">Nunc 96-Well Polystyrene Conical Bottom MicroWell Plates</td>
			<td style="width:119px;">Thermo Fisher Scienctific</td>
			<td style="width:123px;">249570</td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Puralub Vet Ointment</td>
			<td style="width:119px;">Dechra</td>
			<td style="width:123px;">9N-76855</td>
			<td style="width:121px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:295px;">Fluorescent microscope</td>
			<td style="width:119px;">Olympus</td>
			<td>Olympus IX81</td>
			<td style="width:121px;"></td>
		</tr>
	</tbody>
</table>

influenza a virus studies in a mouse model of infection

Influenza-Viren verursachen mehr als 500.000 Todesfälle weltweit1 und eine jährliche Gebühr von 12 Milliarden US-Dollar in den Vereinigten Staaten allein in Anbetracht direkte medizinische und Krankenhausaufenthalt Kosten und Arbeit Absentismus2zugeordnet sind. Tiermodelle sind entscheidend für Influenza A Virus (IAV) Studien zur Bewertung virale Pathogenese, Wirt-Pathogen Interaktionen, Immunreaktionen und nähert sich die Wirksamkeit der laufenden bzw. neuartige Impfstoff sowie antivirale Medikamente. Mäuse sind vorteilhaft kleine Tiermodell, weil ihr Immunsystem evolutionär ähnelt, findet man bei Menschen, es gibt Sie von kommerziellen Anbietern als genetisch identische Themen, gibt es mehrere Stämme, die ausgenutzt werden können, um zu bewerten die genetische Grundlage von Infektionen, und sie sind relativ preiswert und leicht zu manipulieren. Um die IAV-Infektion beim Menschen über die Atemwege zu rekapitulieren, werden Mäuse zuerst vor der intranasale Inokulation mit infektiösen IAVs unter richtigen Biosafety Containment betäubt. Nach Infektion wird die Pathogenese der IAVs bestimmt, indem Sie täglich die Morbidität (Körper-Gewicht-Verlust) und Sterblichkeit (überleben). Darüber hinaus kann virale Pathogenese auch ausgewertet werden, durch die Replikation des Virus in die obere (Nasenschleimhaut) oder der unteren Atemwege (Lunge), von infizierten Mäusen Bewertung. Humorale Reaktionen bei der IAV-Infektion durch nicht-invasive Blutungen und sekundäre Antikörpernachweis schnell auswertbar Assays abzielen, das Vorhandensein von insgesamt oder neutralisierenden Antikörpern. Hier beschreiben wir die gängige Methoden, Mäuse intranasal zu infizieren (i.n) mit IAV und Pathogenese, humorale Immunantwort und Schutz Wirksamkeit zu bewerten.

Watch this Scientific Journal Video about Influenza A Virus Studies in a Mouse Model of Infection at JoVE.com

Influenza-A-Virus-Studien in einem Maus-Infektionsmodell | Immunologie und Infektion | Video

Influenza A Virus Studies in a Mouse Model of Infection

Influenza A-Viren (IAVs) sind wichtige Humanpathogene Atemwege. Die Pathogenität von IAVs verstehen und neuartigen Impfstoff präklinischen Erprobung durchführen, sind Tiermodelle imitiert menschliche Physiologie erforderlich. Hier beschreiben wir Techniken zur Bewertung IAV Pathogenese, humorale Reaktionen und Wirksamkeit des Impfstoffes mit einem Maus-Modell der Infektion.

Influenza-A-Virus-Studien in einem Mausmodell der Infektion

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 ...

influenza-a-virus-studies-in-a-mouse-model-of-infection

Nanyang Technological University

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SCIENTISTS IN ACTION

28.0K Aufrufe.  University of Rochester School of Medicine and Dentistry. Influenza A-Viren (IAVs) sind wichtige Humanpathogene Atemwege. Die Pathogenität von IAVs verstehen und neuartigen Impfstoff präklinischen Erprobung durchführen, sind Tiermodelle imitiert menschliche Physiologie erforderlich. Hier beschreiben wir Techniken zur Bewertung IAV Pathogenese, humorale Reaktionen und Wirksamkeit des Impfstoffes mit einem Maus-Modell der Infektion.

Serie: Influenza A Virus Studies in a Mouse Model of Infection

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.

Mit Bioluminescent Imaging, um Synergie von Untersuchen Streptococcus pneumoniae Und Influenza A Virus in Infant Mäuse

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

Forschung

Immunologie und Infektion

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.

Influenza Virus Vermehrung in embryonierten Hühnereiern

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.

Co-Immunopräzipitation der Maus Mx1 Protein mit dem 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 ...

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.

Nasal Tücher für Influenza-A-Virus-Erkennung und Isolierung von Schweine

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.

Mess Bindung und Internalisierung von Influenza A-Virus in A549-Zellen mittels Durchflusszytometrie

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.

Neutrophilen-Isolierung und Analyse zur Bestimmung ihrer Rolle in der Lymphom-Zellempfindlichkeit therapeutische Mittel

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 ...

A Miniaturized Glycan Microarray Assay for Assessing Avidity and Specificity of Influenza A Virus Hemagglutinins

Influenza A virus (IAV) hemagglutinins recognize sialic acids on the cell surface as functional receptors to gain entry into cells. Wild waterfowl are the natural reservoir for IAV, but IAV can cross the species barrier to poultry, swine, horses and humans. Avian viruses recognize sialic acid attached to a penultimate galactose by a &#945;2-3 linkage (avian-type receptors) whereas human viruses preferentially recognize sialic acid with a &#945;2-6 linkage (human-type receptors). To monitor if avian viruses are adapting to human type receptors, several methods can be used. Glycan microarrays with diverse libraries of synthetic sialosides are increasingly used to evaluate receptor specificity. However, this technique is not used for measuring avidities. Measurement of avidity is typically achieved by evaluating the binding of serially diluted hemagglutinin or virus to glycans adsorbed to conventional polypropylene 96-well plates. In this assay, glycans with &#945;2-3 or &#945;2-6 sialic acids are coupled to biotin and adsorbed to streptavidin plates, or are coupled to polyacrylamide (PAA) which directly adsorb to the plastic. We have significantly miniaturized this assay by directly printing PAA-linked sialosides and their non PAA-linked counterparts on micro-well glass slides. This set-up, with 48 arrays on a single slide, enables simultaneous assays of 6 glycan binding proteins at 8 dilutions, interrogating 6 different glycans, including two non-sialylated controls. This is equivalent to 18x 96-well plates in the traditional plate assay. The glycan array format decreases consumption of compounds and biologicals and thus greatly enhances efficiency.

Using a printed glycan microarray strategy, a conventional 96-well plate assay was miniaturized for analysis of influenza A virus hemagglutinin avidity and specificity for sialic acid containing receptors.

Ein miniaturisiertes Glycan Microarray-Test zur Beurteilung der Avidität und Spezifität von Influenza-A-Virus Hämagglutininarten

Influenza A virus (IAV) hemagglutinins recognize sialic acids on the cell surface as functional receptors to gain entry into cells. Wild waterfowl are the ...

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.

In - vitro - Zerlegung von Influenza - A - Virus Kapside durch Gradientenzentrifugation

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

Imaging Cell Interaction in Tracheal Mucosa During Influenza Virus Infection Using Two-photon Intravital Microscopy

The analysis of cell-cell or cell-pathogen interaction in vivo is an important tool to understand the dynamics of the immune response to infection. Two-photon intravital microscopy (2P-IVM) allows the observation of cell interactions in deep tissue in living animals, while minimizing the photobleaching generated during image acquisition. To date, different models for 2P-IVM of lymphoid and non-lymphoid organs have been described. However, imaging of respiratory organs remains a challenge due to the movement associated with the breathing cycle of the animal.
Here, we describe a protocol to visualize in vivo immune cell interactions in the trachea of mice infected with influenza virus using 2P-IVM. To this purpose, we developed a custom imaging platform, which included the surgical exposure and intubation of the trachea, followed by the acquisition of dynamic images of neutrophils and dendritic cells (DC) in the mucosal epithelium. Additionally, we detailed the steps needed to perform influenza intranasal infection and flow cytometric analysis of immune cells in the trachea. Finally, we analyzed neutrophil and DC motility as well as their interactions during the course of a movie. This protocol allows for the generation of stable and bright 4D images necessary for the assessment of cell-cell interactions in the trachea.

In this study, we present a protocol to perform two-photon intravital imaging and cell interaction analysis in the murine tracheal mucosa after infection with influenza virus. This protocol will be relevant for researchers studying immune cell dynamics during respiratory infections.

Bildgebung Zelle Interaktion in Trachealen Schleimhaut während der Influenza-Virus-Infektion mit Intravitalen zwei-Photonen-Mikroskopie

The analysis of cell-cell or cell-pathogen interaction in vivo is an important tool to understand the dynamics of the immune response to infection. ...

A Luciferase-fluorescent Reporter Influenza Virus for Live Imaging and Quantification of Viral Infection

Influenza A viruses (IAVs) cause human respiratory disease that is associated with significant health and economic consequences. As with other viruses, studying IAV requires the use of laborious secondary approaches to detect the presence of the virus in infected cells and/or in animal models of infection. This limitation has been recently circumvented with the generation of recombinant IAVs expressing easily traceable fluorescent or bioluminescent (luciferase) reporter proteins. However, researchers have been forced to select fluorescent or luciferase reporter genes due to the restricted capacity of the IAV genome for including foreign sequences. To overcome this limitation, we have generated a recombinant replication-competent bi-reporter IAV (BIRFLU) stably expressing both a fluorescent and a luciferase reporter gene to easily track IAV infections in vitro and in vivo. To this end, the viral non-structural (NS) and hemagglutinin (HA) viral segments of influenza A/Puerto Rico/8/34 H1N1 (PR8) were modified to encode the fluorescent Venus and the bioluminescent Nanoluc luciferase proteins, respectively. Here, we describe the use of BIRFLU in a mouse model of IAV infection and the detection of both reporter genes using an in vivo imaging system. Notably, we have observed a good correlation between the expressions of both reporters and viral replication. The combination of cutting-edge techniques in molecular biology, animal research and imaging technologies, provides researchers the unique opportunity to use this tool for influenza research, including the study of virus-host interactions and dynamics of viral infections. Importantly, the feasibility to genetically alter the viral genome to express two foreign genes from different viral segments opens up opportunities to use this approach for: (i) the development of novel IAV vaccines, (ii) the generation of recombinant IAVs that can be used as vaccine vectors for the treatment of other human pathogen infections.

Influenza A viruses (IAVs) are contagious respiratory pathogens that cause annual epidemics and occasional pandemics. Here, we describe a protocol to track viral infections in vivo using a novel recombinant luciferase and fluorescence-expressing bi-reporter IAV (BIRFLU). This approach provides researchers with an excellent tool to study IAV in vivo.

Ein luziferasefluoreszierendes Reporter-Influenzavirus zur Live-Bildgebung und Quantifizierung von Virusinfektionen

Influenza A viruses (IAVs) cause human respiratory disease that is associated with significant health and economic consequences. As with other viruses, ...