Diese Studie wurde von NIH R00HL102154 ein American Society of Hematology Scholar Award P Ji unterstützt und.

Die in diesem Protokoll beschriebenen Experimente wurden in Übereinstimmung mit den Richtlinien und Vorschriften her von der Northwestern University Institutional Animal Care und Verwenden Ausschuss durchgeführt. 1. Herstellung des Kulturmediums <ol><li> Bereiten Fibronektin-Lösung. 1 ml Wasser zu einem Fläschchen mit humanem Fibronektin (1 mg). Verlassen Lösung in der Gewebekultur Haube für 30 min ohne Rühren. Dann wird die gesamte Flüssigkeit in 50 ml PBS auf eine Endkonzentration von 20 ug / ml herzustellen und schonend gut mischen. Stellen Sie vor dem Beschichten der Platte (siehe unten) die Fibronektin-Lösung frisch. </li><li> Bereiten Sie 50 ml Epo-freiem Medium (SCF Medium). Kombinieren der aufgeführten Bestandteile in Tabelle 1 aufgeführt. Das Medium kann bei 4 ° C für 1 Monat gelagert, wenn sie frisch hergestellt werden. </li><li> Bereiten Sie 50 ml Epo haltigem Medium. Kombinieren der aufgeführten Bestandteile in Tabelle 2 entspricht. Das Medium kann bei 4 ° C für 1 Monat gelagert, wenn sie frisch hergestellt werden. </li></ol&gt; 2. Fibronektin beschichtete Platte <ol><li> 1 ml Fibronektin-Lösung in jede Vertiefung einer Platte mit 6 Vertiefungen (oder 0,5 ml in jede Vertiefung einer 12-Well-Platte). Verlassen Sie die Platte in der Gewebekultur Haube für 1 Stunde. </li><li> Brunnen mit sterilem Wasser spülen und an der Luft trocknen zweimal die Platte. </li><li> Wickeln Sie die Platte, und speichern Sie im Kühlraum bei 4 ° C. </li></ol> 3. Reinigung der fötalen Leber Erythroblasten HINWEIS: Die Verwendung fötalen Lebern von E13 bis E15 zeitlich schwangeren Mäusen (C57BL / 6). E13.5 Lebern werden bevorzugt, um die Ausbeute der CFU-E-Vorläufer zu maximieren. Die Zeit schwangeren Mäusen erhalten, wurden 6 bis 8 Wochen alten männlichen und weiblichen Mäusen in einem Käfig (meist ein Mann mit einem oder zwei Weibchen) angeordnet ist. Weibliche vaginalen Pfropfen wurden am nächsten Morgen überprüft, um festzustellen, ob die Paarung erfolgreich war. Der erste Tag der Trächtigkeit war der Tag nach der Stecker gefunden wurde. <ol><li> Vorbereitung der Gesamt fötalen Leberzellen <ol><li> Opfer der mouse von CO 2 Einatmen und Genickbruch. Sprühen Sie den Bauch mit 70% Ethanol zur Desinfektion. Öffnen Sie den Bauch mit Dissektionsscheren, um die Gebärmutter zu entfernen. Die Gebärmutter in 1x PBS waschen. </li><li> Sezieren die Föten unter sterilen Bedingungen mit einer Gewebekultur Kapuze und autoklaviert Werkzeuge und waschen in 1x PBS. </li><li> Sezieren die fötale Leber von Föten. Halten Sie den Körper des Fötus mit einer Pinzette vorsichtig ziehen die fötale Leber (rosa Farbe) vom Körper mit einer anderen Pinzette. Reinigen Sie die fötale Leber mit der Pinzette, um die zugehörigen fibrotische Gewebe zu entfernen. Legen Sie alle fötalen Lebern in frischem 1x PBS, das 10% fetales Rinderserum. </li><li> Mechanisch stören fetalen Leber durch Pipettieren von oben und unten. </li><li> Filtern der Zellsuspension durch ein 40 um Sieb Zelle in einem 50 ml konischen Röhrchen. Pelletieren Sie die Zellen bei 800 × g für 5 min. </li><li> Saugen Sie den Überstand und resuspendieren der Zellen in 1 ml PBS mit 10% FBS (ca. 8 E13.5 fetalen Leberpro ml). </li></ol></li><li> Reinigung von TER119 Negative Erythroblasten <ol><li> Blockieren der Zellen mit Ratten-IgG (0,2 mg / ml) auf Eis für 15 min. </li><li> Ohne Waschen oder Zentrifugieren, fügen biotinylierten Anti TER119-Antikörper zu der Zellsuspension (1 ug / ml). Die Proben für 15 Minuten auf Eis. </li><li> Waschen in 1x PBS mit 10% FBS (1:10) und zentrifugiert bei 800 g für 5 min. Resuspendieren der Zellen in 1 ml PBS mit 10% FBS. </li><li> Fügen Sie 75 ul Streptavidin mit Magnetpartikel gekoppelt und Inkubation für 10 Minuten auf Eis. </li><li> Hinzufügen des Volumens auf 2,5 ml mit PBS, enthaltend 10% FBS. Übertragen der Zellsuspension in 5 ml-Polypropylen-Röhre mit rundem Boden. </li><li> Legen Sie den Schlauch in einem magnetischen Zellsortiervorrichtung und Inkubation für 10 min. TER119 positiven Zellen wird zu der Seite des Rohrs zu befestigen. Das freie TER119 negativen Erythroblasten in der Suspension verbleiben. </li><li> Gießen Sie die Zellsuspension in eine neue 5 ml Polypropylen-Rundbodenrohr. </li><li><html> Wiederholen Sie die Schritte 3.2.6 und 3.2.7, um die restlichen TER119 positive Zellen zu entfernen. </li><li> Pelletieren Sie die Zellen bei 800 × g für 5 min. Absaugen des Überstandes. Resuspendieren der Zellen in 1 ml PBS, enthaltend 10% FBS und zählen lebende Zellen mit Trypan-Blau. </li></ol></li></ol> 4. Transduktion mit Viren Encoding cDNA oder shRNA <ol><li> Platte der gereinigten TER119 negativen fötalen Leberzellen bei 3-5 x 10 5 / gut in einer Fibronektin beschichteten 12-Well-Platte (Einstellung der Zellzahl, wenn mit einer anderen Platte). </li><li> Hinzufügen Polybren bis zu einer Endkonzentration von 10 ug / ml der viralen Transduktion zu erleichtern. Spin infizieren die Zellen mit Lentiviren oder Retroviren kodierenden cDNA oder shRNA, bei 800 × g für 1-1,5 Stunden bei 37 ° C aufweist. </li></ol> 5. Kultur der transduzierten TER119 Negative Maus fötale Leber Erythroblasten <ol><li> Gen-Funktionen in der frühen Stufe der terminalen Erythropoese Test (1 gestrichelt).&quot;&gt; </ol.><ol><li><ol. li=""> Kultur die transduzierten Zellen in Epo-freiem Medium (SCF-Medium) für 12 Stunden, um die Expression der transduzierten Gene und Wartung der Stammvater Staat zu ermöglichen. </ol.></li><li> Zentrifugieren der Zellen bei 800 × g für 5 min. Saugen Sie den Überstand. Resuspendieren der Zellen in 1 ml Epo enthaltenden Medium in jedem Well einer 12-Well-Platte. </li><li> Nach einer Kultivierung für 24 oder 48 h geerntet, die Zellen für weitere Untersuchungen. </li></ol></li><li> Test Gen-Funktionen in der späten Phase der Klemme Erythropoese (Abbildung 1 durchgezogene Linien). <ol><li> Kultur die transduzierten Zellen sofort in Epo haltigem Medium. </li><li> Nach einer Kultivierung für 24 oder 48 h geerntet, die Zellen für die weiteren Tests. </li></ol></li></ol> 6. Die Färbung der kultivierten fetalen Leberzellen für die Durchflusszytometrie <ol><li> Waschen und resuspendieren der Zellen in 1x PBS. Ernte 2 x 10 5 Zellen kultiviert für die Durchflusszytometrie. </li><li> Bebrütendie Zellen mit Fluorophor-konjugierten Antikörpern für 20 Minuten bei Raumtemperatur im Dunkeln. Um die Differenzierung zu testen, verwenden APC konjugierten anti-CD71 und PE-konjugierten anti-TER119. Um Enukleation zu testen, verwenden Hoechst 33342-Färbung zusätzlich zu den anderen Antikörpern. </li><li> Waschen Sie die Zellen mit 1x PBS. Resuspendieren der Zellen in 0,5 ml PBS, das 1% FBS und Propidiumiodid (PI) (1 ug / ml), um die toten Zellen zu färben und von der Analyse auszuschließen. </li><li> Verhaltensfluss cytrometric Analyse. Analysieren Sie einzelne Farbe gefärbten und ungefärbten Kontrollzellen zunächst für Anpassung und Kompensation der Durchflusszytometer. </li></ol>

<ol>
	<li>Hattangadi, S. M., Wong, P., Zhang, L., Flygare, J., Lodish, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+stem+cell+to+red+cell:+regulation+of+erythropoiesis+at+multiple+levels+by+multiple+proteins,+RNAs,+and+chromatin+modifications.">From stem cell to red cell: regulation of erythropoiesis at multiple levels by multiple proteins, RNAs, and chromatin modifications.</a> Blood. 118 (24), 6258-6268 (2011).</li><li>Richmond, T. D., Chohan, M., Barber, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Turning+cells+red:+signal+transduction+mediated+by+erythropoietin.">Turning cells red: signal transduction mediated by erythropoietin.</a> Trends in cell biology. 15 (3), 146-155 (2005).</li><li>Eshghi, S., Vogelezang, M. G., Hynes, R. O., Griffith, L. G., Lodish, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha4beta1+integrin+and+erythropoietin+mediate+temporally+distinct+steps+in+erythropoiesis:+integrins+in+red+cell+development.">Alpha4beta1 integrin and erythropoietin mediate temporally distinct steps in erythropoiesis: integrins in red cell development.</a> The Journal of cell biology. 177 (5), 871-880 (2007).</li><li>Koury, M. J., Bondurant, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maintenance+by+erythropoietin+of+viability+and+maturation+of+murine+erythroid+precursor+cells.">Maintenance by erythropoietin of viability and maturation of murine erythroid precursor cells.</a> Journal of cellular physiology. 137 (1), 65-74 (1988).</li><li>Ji, P., Yeh, V., Ramirez, T., Murata-Hori, M., Lodish, H. F. <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+2+is+required+for+chromatin+condensation+and+subsequent+enucleation+of+cultured+mouse+fetal+erythroblasts.">Histone deacetylase 2 is required for chromatin condensation and subsequent enucleation of cultured mouse fetal erythroblasts.</a> Haematologica. 95 (12), 2013-2021 (2010).</li><li>Dumitriu, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sox6+cell-autonomously+stimulates+erythroid+cell+survival,+proliferation,+and+terminal+maturation+and+is+thereby+an+important+enhancer+of+definitive+erythropoiesis+during+mouse+development.">Sox6 cell-autonomously stimulates erythroid cell survival, proliferation, and terminal maturation and is thereby an important enhancer of definitive erythropoiesis during mouse development.</a> Blood. 108 (4), 1198-1207 (2006).</li><li>Rector, K., Liu, Y., Van Zant, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comprehensive+hematopoietic+stem+cell+isolation+methods.">Comprehensive hematopoietic stem cell isolation methods.</a> Methods in molecular biology. 976, 1-15 (2013).</li><li>Rossi, L., Challen, G. A., Sirin, O., Lin, K. K., Goodell, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hematopoietic+stem+cell+characterization+and+isolation.">Hematopoietic stem cell characterization and isolation.</a> Methods in molecular biology. 750, 47-59 (2011).</li><li>Choi, H. S., Lee, E. M., Kim, H. O., Park, M. I., Baek, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomous+control+of+terminal+erythropoiesis+via+physical+interactions+among+erythroid+cells.">Autonomous control of terminal erythropoiesis via physical interactions among erythroid cells.</a> Stem cell research. 10 (3), 442-453 (2013).</li><li>Bhatia, H., 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=Short-chain+fatty+acid-mediated+effects+on+erythropoiesis+in+primary+definitive+erythroid+cells.">Short-chain fatty acid-mediated effects on erythropoiesis in primary definitive erythroid cells.</a> Blood. 113 (25), 6440-6448 (2009).</li><li>Zhang, J., Socolovsky, M., Gross, A. W., Lodish, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+Ras+signaling+in+erythroid+differentiation+of+mouse+fetal+liver+cells:+functional+analysis+by+a+flow+cytometry-based+novel+culture+system.">Role of Ras signaling in erythroid differentiation of mouse fetal liver cells: functional analysis by a flow cytometry-based novel culture system.</a> Blood. 102 (12), 3938-3946 (2003).</li><li>Socolovsky, M., 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=Ineffective+erythropoiesis+in+Stat5a(-/-)5b(-/-)+mice+due+to+decreased+survival+of+early+erythroblasts.">Ineffective erythropoiesis in Stat5a(-/-)5b(-/-) mice due to decreased survival of early erythroblasts.</a> Blood. 98 (12), 3261-3273 (2001).</li><li>Ji, P., Jayapal, S. R., Lodish, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enucleation+of+cultured+mouse+fetal+erythroblasts+requires+Rac+GTPases+and+mDia2.">Enucleation of cultured mouse fetal erythroblasts requires Rac GTPases and mDia2.</a> Nature cell biology. 10 (3), 314-321 (2008).</li><li>Chida, D., Miura, O., Yoshimura, A., Miyajima, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+cytokine+signaling+molecules+in+erythroid+differentiation+of+mouse+fetal+liver+hematopoietic+cells:+functional+analysis+of+signaling+molecules+by+retrovirus-mediated+expression.">Role of cytokine signaling molecules in erythroid differentiation of mouse fetal liver hematopoietic cells: functional analysis of signaling molecules by retrovirus-mediated expression.</a> Blood. 93 (5), 1567-1578 (1999).</li><li>Patel, V. P., Lodish, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+fibronectin+matrix+is+required+for+differentiation+of+murine+erythroleukemia+cells+into+reticulocytes.">A fibronectin matrix is required for differentiation of murine erythroleukemia cells into reticulocytes.</a> The Journal of cell biology. 105 (6 Pt 2), 3105-3118 (1987).</li><li>Udupa, K. B., Lipschitz, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endotoxin-induced+suppression+of+erythropoiesis:+the+role+of+erythropoietin+and+a+heme+synthesis+stimulating+factor.">Endotoxin-induced suppression of erythropoiesis: the role of erythropoietin and a heme synthesis stimulating factor.</a> Blood. 59 (6), 1267-1271 (1982).</li><li>Koury, M. J., Sawyer, S. T., Brandt, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+insights+into+erythropoiesis.">New insights into erythropoiesis.</a> Current opinion in hematology. 9 (2), 93-100 (2002).</li></ol>

Die Autoren erklären, dass sie keine finanziellen Interessen konkurrieren.

Hier präsentieren wir ein einzigartiges System chronologisch analysieren Maus fötalen Leber Terminal Erythropoese. Durch die Anwendung der verschiedenen Kulturbedingungen haben wir erfolgreich seziert Terminal Erythropoese in frühen und späten Stadien. Dies ist besonders wichtig, die Mechanismen von Genen mit mehreren Funktionen zu bestimmen. Zum Beispiel spielen Rac GTPasen wichtige Rollen in verschiedenen Stadien der Erythropoese Terminal. Hemmung der Rac GTPasen in der frühen Stufe der terminalen Erythropoese Ei...

Erythropoiese ist der Prozess der Differenzierung der multipotenten hämatopoetischen Stammzellen zu reifen Erythrozyten. Dieses schrittweise Verfahren umfasst die Bildung von erythroiden Bursts engagierten bildenden Einheiten (BFU-E), die sich schnell teilende erythroide Kolonien bildenden Einheiten (CFU-E) und morphologisch erkennbaren Erythroblasten 1,2. Terminal Erythropoese von CFU-E-Vorläuferzellen beinhaltet sequentielle Erythropoietin-abhängigen und unabhängigen Stufen 2,3. In der frühen Stufe der terminalen Erythropoese, Erythropoietin (Epo) bindet an seinen Rezeptor auf der Zelloberfläche und induziert eine Reihe von stromabwärts gelegenen Signalwege, die Apoptose zu verhindern und eine schnelle Zellteilung und Genexpression 1,4. In der späten Phase der Klemme Erythropoese, Erythroblasten unterziehen Ausfahrt Terminal Zellzyklus, Chromatin und Kern Kondensation und Extrusion der höher kondensierten Kernen 5. Unser Verständnis von TerminalErythropoese hat sich in den letzten Jahrzehnten, die weitgehend auf die erfolgreiche Verwendung von mehreren in vitro und in-vivo-Maus-Modellen 6-9 verbessert. Unter diesen Modellen in vitro-Kultur von Maus fötale Leber Erythroblasten bietet viele Vorteile, einschließlich der einfachen Zellreinigung, schnelle Proliferation und Differenzierung, und eine engere menschliche Mimik Erythropoese 10,11. In diesem System kann eine große Anzahl von Erythrozyten-Vorläuferzellen aus der Maus fetalen Leber leicht durch den Schritt Reinigung von TER119 (ein Marker für den reifen Erythrozyten) negativ Erythroblasten isoliert werden. Während des zweitägigen Kultur der Erythroblasten, kann die Differenzierung dieser Zellen durch eine durchflusszytometrische Analyse, basierend auf Oberflächenexpression des Transferrin-Rezeptors (CD71) und dem Antigen TER119 12 überwacht werden. Zusätzlich kann Enukleation der terminal Differenzierung von Erythroblasten von einer DNA-Hersteller (Hoechst 33342) 1 erkannt werden3. Weiterhin können die gereinigten Vorläuferzellen genetisch durch exogene Expression von cDNAs oder small hairpin RNAs (shRNAs) für die Gene von Interesse, die die mechanistische Untersuchungen der Funktionen der Genexpression auf die Erythropoese 11,13,14 erleichtert modifiziert werden. Andererseits kann die schnelle Zellwachstumsrate ein zweischneidiges Schwert, da es schwierig ist, Genfunktionen in verschiedenen Stadien der Erythropoese Anschluß charakterisieren. In den meisten Fällen ist es schwierig zu bestimmen, ob ein bestimmtes Gen-Funktionen in der frühen Stufe der terminalen Erythropoese, da bis zum Zeitpunkt der cDNAs oder shRNAs ausgedrückt, bereits frühzeitig bestanden die Zellen. Um dieses Problem zu lösen, ein einzigartiges System, um die frühen und späten Stadien der Erythropoese Anschluß sezieren entwickelt. Für die frühe Stufe der terminalen Erythropoese, wurden genetisch modifizierte TER119 negativen Erythroblasten in Epo-freien Medium, jedoch mit Stammzellfaktor (SCF) kultiviert, IL-6 und FLT3Liganden an ihre Vorläufer Zustand zu erhalten und ermöglichen die transduzierten cDNAs oder shRNA Expressions 13. Die Zellen wurden auf Epo enthaltenden Medium nach 12 h geändert wurde, die Zellproliferation und Differenzierung zu induzieren. Auf diese Weise, wenn die Zellen begannen, zu differenzieren, die transduzierten cDNAs oder shRNAs wurden bereits angegeben. Für die späte Phase der Klemme Erythropoese waren TER119 negativen Erythroblasten in Epo haltigem Medium unmittelbar nach Transduktion kultiviert. Daher kann man die Funktionen der Gene von Interesse in der späten Phase der Klemmen Erythropoese zu analysieren. Zusammenfassend würde eine breite Anwendung dieses Systems sezieren Gen-Funktionen in verschiedenen Stadien der Erythropoese Klemme zu helfen.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Iscove&#39;s Modified Dulbecco&#39;s MediumIMDM (IMDM)</td>
			<td>Gibco</td>
			<td>12440-053</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum (FBS)</td>
			<td>GEMINI Bio-product</td>
			<td>700-102P</td>
			<td></td>
		</tr>
		<tr>
			<td>b-mecaptoethanol</td>
			<td>Sigma</td>
			<td>M6250</td>
			<td>0.1 M in IMDM,&#160; 4&#8451;stock</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin solution</td>
			<td>Hyclone</td>
			<td>SV30010</td>
			<td>100 X</td>
		</tr>
		<tr>
			<td>L-Glutamine</td>
			<td>Hyclone</td>
			<td>SH30034.01</td>
			<td>200 mM</td>
		</tr>
		<tr>
			<td>Stem cell factor (SCF)</td>
			<td>STEMCELL TECH</td>
			<td>2630</td>
			<td>100 ng/ul, -20&#8451; stock</td>
		</tr>
		<tr>
			<td>Mouse FIT3 Ligand (Flt-3L)</td>
			<td>BD Biosciences&#160;</td>
			<td>14-8001-80</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse Recombinant Interleukin-6 (IL-6)&#160;</td>
			<td>GEMINI Bio-product</td>
			<td>300-327P</td>
			<td></td>
		</tr>
		<tr>
			<td>fibronectin</td>
			<td>BD Biosciences&#160;</td>
			<td>354008</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>STEMCELL TECH</td>
			<td>9300</td>
			<td>10% stock in IMDM</td>
		</tr>
		<tr>
			<td>Insulin solution, human</td>
			<td>Sigma</td>
			<td>I9278</td>
			<td>4&#8451; stock</td>
		</tr>
		<tr>
			<td>holo-transferrin human</td>
			<td>Sigma</td>
			<td>T0665</td>
			<td>50 mg/ml in Water -20&#8451; stock</td>
		</tr>
		<tr>
			<td>Erythropoietin(Epo)</td>
			<td>PROCRIT</td>
			<td>NOC 59676-303-00</td>
			<td>3,000 U/ml stock</td>
		</tr>
		<tr>
			<td>Streptavidin particles Plus</td>
			<td>BD Pharmingen</td>
			<td>557812</td>
			<td></td>
		</tr>
		<tr>
			<td>EasySep Magnet</td>
			<td>STEMCELL TECH</td>
			<td>18000</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene Round-Bottom Tube, 5 ml</td>
			<td>FALCON</td>
			<td>352063</td>
			<td></td>
		</tr>
	</tbody>
</table>

mouse fetal liver culture system to dissect target gene functions at the early and late stages of terminal erythropoiesis

Erythropoese beinhaltet ein dynamischer Prozess, der mit engagierten Erythroid-Burst-bildende Einheiten (BFU-E), gefolgt von sich schnell teilenden erythroiden Kolonien bildenden Einheiten (CFU-E) beginnt. Nach CFU-Es sind Zellen morphologisch erkennbar und in der Regel Terminal Erythroblasten bezeichnet. Eine der Herausforderungen bei der Untersuchung der terminalen Erythropoese ist der Mangel an experimentellen Ansätzen, um Genfunktionen in chronologischer Weise zerlegen. In diesem Protokoll beschreiben wir eine einzigartige Strategie Genfunktionen in der frühen und späten Stadien der Erythropoese Endgerät bestimmen. In diesem System wurden Maus fötalen Leber TER119 (reifen Erythrozyten-Zellmarker) negativ Erythroblasten gereinigt und mit exogenen Expression von cDNAs oder kleine Haarnadel RNAs (shRNAs) für die Gene von Interesse transduziert. Anschließend wurden die Zellen in Medium, das außer Erythropoietin (Epo), ihre Vorläuferstufe für 12 Stunden beibehalten, während man die exogene cDNA oder shRNAs Wachstumsfaktoren kultiviertzum Ausdruck zu bringen. Die Zellen wurden auf Epo Medium nach 12 h geändert wurde, um die Zelldifferenzierung und Proliferation zu induzieren, während die exogene genetische Materialien wurden bereits angegeben. Dieses Protokoll ermöglicht Analyse der Genfunktionen in der frühen Stufe der terminalen Erythropoese. Zu spät Terminal Erythropoese zu untersuchen, wurden Zellen sofort in Epo Medium nach Transduktion kultiviert. Auf diese Weise wurden die Zellen bereits mit dem späten Stadium der terminalen Erythropoese unterschieden, wenn die transduzierten genetischen Materialien wurden exprimiert. Wir empfehlen eine allgemeine Anwendung dieser Strategie, die Ihnen helfen zu verstehen, detaillierte Gen-Funktionen in verschiedenen Stadien der Erythropoese Terminal würde.

Abbildung 1 skizziert die experimentellen Strategien. Das Protokoll besteht aus zwei unabhängige Bedingungen für die Ausrichtung der Funktionen der Signalmoleküle in den frühen und späten Stadien der Erythropoese Terminal. TER119 negativen fötale Leber Erythroblasten wurden aus E13.5 Maus Fötus gereinigt. Durchflusszytometrische Analyse der fötalen Leber erythroiden Zellen vor und nach der Reinigung zeigte, daß die Reinigung effizient war (2A und 2B). Für die ...

Watch this Scientific Journal Video about Mouse Fetal Liver Culture System to Dissect Target Gene Functions at the Early and Late Stages of Terminal Erythropoiesis at JoVE.com

Mouse Fetal Liver Culture System to Dissect Target Gene Functions at the Early and Late Stages of Terminal Erythropoiesis

Wir stellen ein in-vitro-Maus fötalen Leber Erythroblasten Kultursystem, das die frühen und späten Stadien der Erythropoese Anschluß seziert. Dieses System erleichtert die funktionelle Analyse von spezifischen Genen in verschiedenen Entwicklungsstadien.

Maus fötalen Leberkultursystem zur Ziel Gen-Funktionen in der frühen und späten Stadien der Klemme Erythropoese Dissect

Erythropoiesis involves a dynamic process that begins with committed erythroid burst forming units (BFU-Es) followed by rapidly dividing erythroid colony ...

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Research

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JoVE Journal

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Cell Biology

Immunology and Infection

Unit 1

A Hierarchical Stem-Cell System: Blood Cell Formation

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14.9K Aufrufe.  Northwestern University.  Wir stellen ein in-vitro-Maus fötalen Leber Erythroblasten Kultursystem, das die frühen und späten Stadien der Erythropoese Anschluß seziert. Dieses System erleichtert die funktionelle Analyse von spezifischen Genen in verschiedenen Entwicklungsstadien. 

Serie: Mouse Fetal Liver Culture System to Dissect Target Gene Functions at the Early and Late Stages of Terminal Erythropoiesis

Introducing Shear Stress in the Study of Bacterial Adhesion

During bacterial infections a sequence of interactions occur between the pathogen and its host. Bacterial adhesion to the host cell surface is often the initial and determining step of the pathogenesis. Although experimentally adhesion is mostly studied in static conditions adhesion actually takes place in the presence of flowing liquid. First encounters between bacteria and their host often occur at the mucosal level, mouth, lung, gut, eye, etc. where mucus flows along the surface of epithelial cells. Later in infection, pathogens occasionally access the blood circulation causing life-threatening illnesses such as septicemia, sepsis and meningitis. A defining feature of these infections is the ability of these pathogens to interact with endothelial cells in presence of circulating blood. The presence of flowing liquid, mucus or blood for instance, determines adhesion because it generates a mechanical force on the pathogen. To characterize the effect of flowing liquid one usually refers to the notion of shear stress, which is the tangential force exerted per unit area by a fluid moving near a stationary wall, expressed in dynes/cm2. Intensities of shear stress vary widely according to the different vessels type, size, organ, location etc. (0-100 dynes/cm2). Circulation in capillaries can reach very low shear stress values and even temporarily stop during periods ranging between a few seconds to several minutes 1. On the other end of the spectrum shear stress in arterioles can reach 100 dynes/cm2 2. The impact of shear stress on different biological processes has been clearly demonstrated as for instance during the interaction of leukocytes with the endothelium 3. To take into account this mechanical parameter in the process of bacterial adhesion we took advantage of an experimental procedure based on the use of a disposable flow chamber 4. Host cells are grown in the flow chamber and fluorescent bacteria are introduced in the flow controlled by a syringe pump. We initially focused our investigations on the bacterial pathogen Neisseria meningitidis, a Gram-negative bacterium responsible for septicemia and meningitis. The procedure described here allowed us to study the impact of shear stress on the ability of the bacteria to: adhere to cells 1, to proliferate on the cell surface 5and to detach to colonize new sites 6 (Figure 1). Complementary technical information can be found in reference 7. Shear stress values presented here were chosen based on our previous experience1 and to represent values found in the literature. The protocol should be applicable to a wide range of pathogens with specific adjustments depending on the objectives of the study.

During the infection process, a key step is the adhesion of pathogens with host cells. In most instances this adhesion step occurs in the presence of mechanical stress generated by flowing liquid. We describe a technique that introduces shear stress as an important parameter in the study of bacterial adhesion.

Introducing Schubspannung in der Studie der bakteriellen Adhäsion

During bacterial infections a sequence of interactions occur between the pathogen and its host. Bacterial adhesion to the host cell surface is often the ...

Forschung

Immunologie und Infektion

Using the BLT Humanized Mouse as a Stem Cell based Gene Therapy Tumor Model

Small animal models such as mice have been extensively used to study human disease and to develop new therapeutic interventions. Despite the wealth of information gained from these studies, the unique characteristics of mouse immunity as well as the species specificity of viral diseases such as human immunodeficiency virus (HIV) infection led to the development of humanized mouse models. The earlier models involved the use of C. B 17 scid/scid mice and the transplantation of human fetal thymus and fetal liver termed thy/liv (SCID-hu) 1, 2 or the adoptive transfer of human peripheral blood leukocytes (SCID-huPBL) 3. Both models were mainly utilized for the study of HIV infection.
One of the main limitations of both of these models was the lack of stable reconstitution of human immune cells in the periphery to make them a more physiologically relevant model to study HIV disease. To this end, the BLT humanized mouse model was developed. BLT stands for bone marrow/liver/thymus. In this model, 6 to 8 week old NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) immunocompromised mice receive the thy/liv implant as in the SCID-hu mouse model only to be followed by a second human hematopoietic stem cell transplant 4. The advantage of this system is the full reconstitution of the human immune system in the periphery. This model has been used to study HIV infection and latency 5-8.
We have generated a modified version of this model in which we use genetically modified human hematopoietic stem cells (hHSC) to construct the thy/liv implant followed by injection of transduced autologous hHSC 7, 9. This approach results in the generation of genetically modified lineages. More importantly, we adapted this system to examine the potential of generating functional cytotoxic T cells (CTL) expressing a melanoma specific T cell receptor. Using this model we were able to assess the functionality of our transgenic CTL utilizing live positron emission tomography (PET) imaging to determine tumor regression (9).
The goal of this protocol is to describe the process of generating these transgenic mice and assessing in vivo efficacy using live PET imaging. As a note, since we use human tissues and lentiviral vectors, our facilities conform to CDC NIH guidelines for Biosafety Level 2 (BSL2) with special precautions (BSL2+). In addition, the NSG mice are severely immunocompromised thus, their housing and maintenance must conform to the highest health standards (<a href="http://jaxmice.jax.org/research/immunology/005557-housing.html" target="_blank">http://jaxmice.jax.org/research/immunology/005557-housing.html</a>).

The generation and characterization of tumor specific T cells using humanized mice is described here. Human thymic tissue and genetically modified human hematopoietic stem cells are transplanted into immunocompromised mice. This results in the reconstitution of an engineered human immune system allowing for in vivo examination of anti-tumor immune responses.

Mit der BLT humanisierte Maus als Stem Cell based Gene Therapy Tumormodell

Small animal models such as mice have been extensively used to study human  disease and to develop new therapeutic interventions. Despite the wealth of  ...

Multi-target Parallel Processing Approach for Gene-to-structure Determination of the Influenza Polymerase PB2 Subunit

Pandemic outbreaks of highly virulent influenza strains can cause widespread morbidity and mortality in human populations worldwide. In the United States alone, an average of 41,400 deaths and 1.86 million hospitalizations are caused by influenza virus infection each year 1. Point mutations in the polymerase basic protein 2 subunit (PB2) have been linked to the adaptation of the viral infection in humans 2. Findings from such studies have revealed the biological significance of PB2 as a virulence factor, thus highlighting its potential as an antiviral drug target.
The structural genomics program put forth by the National Institute of Allergy and Infectious Disease (NIAID) provides funding to Emerald Bio and three other Pacific Northwest institutions that together make up the Seattle Structural Genomics Center for Infectious Disease (SSGCID). The SSGCID is dedicated to providing the scientific community with three-dimensional protein structures of NIAID category A-C pathogens. Making such structural information available to the scientific community serves to accelerate structure-based drug design.
Structure-based drug design plays an important role in drug development. Pursuing multiple targets in parallel greatly increases the chance of success for new lead discovery by targeting a pathway or an entire protein family. Emerald Bio has developed a high-throughput, multi-target parallel processing pipeline (MTPP) for gene-to-structure determination to support the consortium. Here we describe the protocols used to determine the structure of the PB2 subunit from four different influenza A strains.

Structure-based drug design plays an important role in drug development. Pursuing multiple targets in parallel greatly increases the chance of success for lead discovery. The following article highlights how the Seattle Structural Genomics Center for Infectious Disease utilizes a multi-target approach for gene-to-structure determination of the PB2 influenza A subunit.

Multi-Target-Parallel Processing Ansatz zur Gene-to-Struktur Bestimmung der Influenza Polymerase PB2-Untereinheit

Pandemic outbreaks of highly virulent influenza strains can cause widespread morbidity and mortality in human populations worldwide. In the United States ...

A Protocol for Analyzing Hepatitis C Virus Replication

Hepatitis C Virus (HCV) affects 3% of the world&#8217;s population and causes serious liver ailments including&#160;chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HCV is an enveloped RNA virus belonging to the family Flaviviridae. Current treatment is not fully effective and causes adverse side effects. There is no HCV vaccine available. Thus, continued effort is required for developing a vaccine and better therapy. An HCV cell culture system is critical for studying various stages of HCV growth including viral entry, genome replication, packaging, and egress. In the current procedure presented, we used a wild-type intragenotype 2a chimeric virus, FNX-HCV, and a recombinant FNX-Rluc virus carrying a Renilla luciferase reporter gene to study the virus replication. A human hepatoma cell line (Huh-7 based) was used for transfection of in vitro transcribed HCV genomic RNAs. Cell-free culture supernatants, protein lysates and total RNA were harvested at various time points post-transfection to assess HCV growth. HCV genome replication status was evaluated by quantitative RT-PCR and visualizing the presence of HCV double-stranded RNA. The HCV protein expression was verified by Western blot and immunofluorescence assays using antibodies specific for HCV NS3 and NS5A proteins. HCV RNA transfected cells released infectious particles into culture supernatant and the viral titer was measured. Luciferase assays were utilized to assess the replication level and infectivity of reporter HCV. In conclusion, we present various virological assays for characterizing different stages of the HCV replication cycle.

Hepatitis C Virus (HCV) is a major human pathogen that causes liver disorders, including cirrhosis and cancer. An HCV infectious cell culture system is essential for understanding the molecular mechanism of HCV replication and developing new therapeutic approaches. Here we describe a protocol to investigate various stages of the HCV replication cycle.

Ein Protokoll für die Analyse von Hepatitis-C-Virus-Replikation

Hepatitis C Virus (HCV) affects 3% of the world&#8217;s population and causes serious liver ailments including&#160;chronic hepatitis, cirrhosis, and ...

Vaccinia Reporter Viruses for Quantifying Viral Function at All Stages of Gene Expression

Poxviruses are a family of double stranded DNA viruses that include active human pathogens such as monkeypox, molluscum contagiousum, and Contagalo virus. The family also includes the smallpox virus, Variola. Due to the complexity of poxvirus replication, many questions still remain regarding their gene expression strategy. In this article we describe the conceptualization and usage of recombinant vaccinia viruses that enable real-time measurement of single and multiple stages of viral gene expression in a high-throughput format. This is enabled through the use of spectrally distinct fluorescent proteins as reporters for each of three stages of viral replication. These viruses provide a high signal-to-noise ratio while retaining stage specific expression patterns, enabling plate-based assays and microscopic observations of virus propagation and replication. These tools have uses for antiviral discovery, studies of the virus-host interaction, and evolutionary biology.

We describe the usage of a fluorescent reporter vaccinia virus that enables real-time measurement of viral infectivity and gene expression through the stage-specific expression of spectrally distinct reporter fluorophores. We detail a plate-based method for accurately identifying the stage at which virus replication is affected in response to small molecule inhibition.

Vaccinia-Viren Reporter zur Quantifizierung von Viral-Funktion auf allen Stufen der Genexpression

Poxviruses are a family of double stranded DNA viruses that include active human pathogens such as monkeypox, molluscum contagiousum, and Contagalo virus. ...

Isolation of Leukocytes from the Murine Tissues at the Maternal-Fetal Interface

Immune tolerance in pregnancy requires that the immune system of the mother undergoes distinctive changes in order to accept and nurture the developing fetus. This tolerance is initiated during coitus, established during fecundation and implantation, and maintained throughout pregnancy. Active cellular and molecular mediators of maternal-fetal tolerance are enriched at the site of contact between fetal and maternal tissues, known as the maternal-fetal interface, which includes the placenta and the uterine and decidual tissues. This interface is comprised of stromal cells and infiltrating leukocytes, and their abundance and phenotypic characteristics change over the course of pregnancy. Infiltrating leukocytes at the maternal-fetal interface include neutrophils, macrophages, dendritic cells, mast cells, T cells, B cells, NK cells, and NKT cells that together create the local micro-environment that sustains pregnancy. An imbalance among these cells or any inappropriate alteration in their phenotypes is considered a mechanism of disease in pregnancy. Therefore, the study of leukocytes that infiltrate the maternal-fetal interface is essential in order to elucidate the immune mechanisms that lead to pregnancy-related complications. Described herein is a protocol that uses a combination of gentle mechanical dissociation followed by a robust enzymatic disaggregation with a proteolytic and collagenolytic enzymatic cocktail to isolate the infiltrating leukocytes from the murine tissues at the maternal-fetal interface. This protocol allows for the isolation of high numbers of viable leukocytes (&#62;70%) with sufficiently conserved antigenic and functional properties. Isolated leukocytes can then be analyzed by several techniques, including immunophenotyping, cell sorting, imaging, immunoblotting, mRNA expression, cell culture, and in vitro functional assays such as mixed leukocyte reactions, proliferation, or cytotoxicity assays.

Described herein is a protocol to isolate and analyze the infiltrating leukocytes of tissues at the maternal-fetal interface (uterus, decidua, and placenta) of mice. This protocol maintains the integrity of most cell surface markers and yields enough viable cells for downstream applications including flow cytometry analysis.

Isolierung von Leukozyten aus dem Mausgeweben an der Maternal-Fetal-Schnittstelle

Immune tolerance in pregnancy requires that the immune system of the mother undergoes distinctive changes in order to accept and nurture the developing ...

Human Placental and Decidual Organ Cultures to Study Infections at the Maternal-fetal Interface

The placenta shows a large degree of interspecies anatomic variability. To best understand biology and pathophysiology of the human placenta, it is imperative to design experiments using human cells and tissues. An advantage of organ culture is maintenance of three-dimensional (3D) structural organization and extracellular matrix. The goal of the method described here is successful establishment of ex vivo human gestational tissue organ cultures and their healthy culture maintenance for 72-96 hr. The protocol details the immediate processing of research-consented, placental and decidual specimens fresh from the operating suite. These are abundant specimens that would otherwise be discarded. Detailed instructions on the sterile collection of these samples, including morphologic details on how to select appropriate tissues to establish 3D organ cultures, is provided. Placental villous and decidual tissues are microdissected into 2-3 mm3 pieces and placed separately on matrix-lined transwell filters and cultured for several days. Villous and decidual organ cultures are well suited for the study of human host-pathogen interaction. As compared to other model organisms, these human cultures are particularly advantageous to examine mechanism of infection for pathogens that demonstrate variable patterns of host specificity. As an example, we demonstrate infection of placental and decidual organ cultures with the clinically relevant, facultative intracellular bacterial pathogen Listeria monocytogenes.

A simple method to establish primary human placental (villous) and decidual organ cultures is described. Villous and decidual organ cultures are invaluable tools for studying pathogenesis at the human maternal-fetal interface. Infection with the facultative intracellular bacterium Listeria monocytogenes is demonstrated.

Menschliche Plazenta und Deziduale Organkulturen Infektionen zu studieren an der Maternal-fetale Schnittstelle

The placenta shows a large degree of interspecies anatomic variability. To best understand biology and pathophysiology of the human placenta, it is ...

Flow Cytometry-based Assay for the Monitoring of NK Cell Functions

Natural killer (NK) cells are an important part of the human tumor immune surveillance system. NK cells are able to distinguish between healthy and virus-infected or malignantly transformed cells due to a set of germline encoded inhibitory and activating receptors. Upon virus or tumor cell recognition a variety of different NK cell functions are initiated including cytotoxicity against the target cell as well as cytokine and chemokine production leading to the activation of other immune cells. It has been demonstrated that accurate NK cell functions are crucial for the treatment outcome of different virus infections and malignant diseases. Here a simple and reliable method is described to analyze different NK cell functions using a flow cytometry-based assay. NK cell functions can be evaluated not only for the whole NK cell population, but also for different NK cell subsets. This technique enables scientists to easily study NK cell functions in healthy donors or patients in order to reveal their impact on different malignancies and to further discover new therapeutic strategies.

A simple and reliable method is described here to analyze a set of NK cell functions such as degranulation, cytokine and chemokine production within different NK cell subsets.

Durchflusszytometrie-basierte Assay zur Überwachung von NK-Zell-Funktionen

Natural killer (NK) cells are an important part of the human tumor immune surveillance system. NK cells are able to distinguish between healthy and ...

Development of a Hepatitis B Virus Reporter System to Monitor the Early Stages of the Replication Cycle

Currently, it is possible to construct recombinant forms of various viruses, such as human immunodeficiency virus 1 (HIV-1) and hepatitis C virus (HCV), that carry foreign genes such as a reporter or marker protein in their genomes. These recombinant viruses usually faithfully mimic the life cycle of the original virus in infected cells and exhibit the same host range dependence. The development of a recombinant virus enables the efficient screening of inhibitors and the identification of specific host factors. However, to date the construction of recombinant hepatitis B virus (HBV) has been difficult because of various experimental limitations. The main limitation is the compact genome size of HBV, and a fairly strict genome size that does not exceed 1.3 genome sizes, that must be packaged into virions. Thus, the size of a foreign gene to be inserted should be smaller than 0.4 kb if no deletion of the genome DNA is to be performed. Therefore, to overcome this size limitation, the deletion of some HBV DNA is required. Here, we report the construction of recombinant HBV encoding a reporter gene to monitor the early stage of the HBV replication cycle by replacing part of the HBV core-coding region with the reporter gene by deleting part of the HBV pol coding region. Detection of recombinant HBV infection, monitored by the reporter activity, was highly sensitive and less expensive than detection using the currently available conventional methods to evaluate HBV infection. This system will be useful for a number of applications including high-throughput screening for the identification of anti-HBV inhibitors, host factors and virus-susceptible cells.

Here we describe a newly developed hepatitis B virus (HBV) reporter system to monitor the early stages of the HBV life cycle. This simplified in vitro system will aid in the screening of anti-HBV agents using a high-throughput strategy.

Entwicklung eines Systems Hepatitis-B-Virus Reporter den frühen Stadien des Replikationszyklus zu überwachen

Currently, it is possible to construct recombinant forms of various viruses, such as human immunodeficiency virus 1 (HIV-1) and hepatitis C virus (HCV), ...

Generation of Escape Variants of Neutralizing Influenza Virus Monoclonal Antibodies

Influenza viruses exhibit a remarkable ability to adapt and evade the host immune response. One way is through antigenic changes that occur on the surface glycoproteins of the virus. The generation of escape variants is a powerful method in elucidating how viruses escape immune detection and in identifying critical residues required for antibody binding. Here, we describe a protocol on how to generate influenza A virus escape variants by utilizing human or murine monoclonal antibodies (mAbs) directed against the viral hemagglutinin (HA). With the use of our technique, we previously characterized critical residues required for the binding of antibodies targeting either the head or stalk of the novel avian H7N9 HA. The protocol can be easily adapted for other virus systems. Analyses of escape variants are important for modeling antigenic drift, determining single nucleotide polymorphisms (SNPs) conferring resistance and virus fitness, and in the designing of vaccines and/or therapeutics.

We describe a method by which we identify critical residues required for the binding of human or murine monoclonal antibodies that target the viral hemagglutinin of influenza A viruses. The protocol can be adapted to other virus surface glycoproteins and their corresponding neutralizing antibodies.

Generation von Escape Varianten des Influenza-Virus Monoclonal Antikörper neutralisieren

Influenza viruses exhibit a remarkable ability to adapt and evade the host immune response. One way is through antigenic changes that occur on the surface ...