بدعم من معهد باستور، INSERM، الوكالة الوطنية للبحوث وكالة الاستخبارات الوطنية (غرانت اللمفاويات &#39;)، وإعادة إحياء برنامج الاستثمار في المستقبل و &quot;لا دوري الدرجة مناهضة للسرطان&quot;.

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J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MHC+class+II-positive+epithelium+and+mesenchyme+cells+are+both+required+for+T-cell+development+in+the+thymus.">MHC class II-positive epithelium and mesenchyme cells are both required for T-cell development in the thymus.</a> Nature. 362, 70-73 (1993).</li><li>Douagi, I., Andre, I., Ferraz, J. C., Cumano, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+T+cell+precursor+activity+in+the+murine+fetal+thymus:+evidence+for+an+input+of+T+cell+precursors+between+days+12+and+14+of+gestation.">Characterization of T cell precursor activity in the murine fetal thymus: evidence for an input of T cell precursors between days 12 and 14 of gestation.</a> Eur J Immunol. 30, 2201-2210 (2000).</li><li>Calderon, L., Boehm, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synergistic,+context-dependent,+and+hierarchical+functions+of+epithelial+components+in+thymic+microenvironments.">Synergistic, context-dependent, and hierarchical functions of epithelial components in thymic microenvironments.</a> Cell. 149, 159-172 (2012).</li><li>Adolfsson, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+Flt3++lympho-myeloid+stem+cells+lacking+erythro-megakaryocytic+potential+a+revised+road+map+for+adult+blood+lineage+commitment.">Identification of Flt3+ lympho-myeloid stem cells lacking erythro-megakaryocytic potential a revised road map for adult blood lineage commitment.</a> Cell. 121, 295-306 (2005).</li><li>Kondo, M., Weissman, I. 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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commitment+and+developmental+potential+of+extrathymic+and+intrathymic+T+cell+precursors:+plenty+to+choose+from.">Commitment and developmental potential of extrathymic and intrathymic T cell precursors: plenty to choose from.</a> Immunity. 26, 678-689 (2007).</li><li>Ramond, C., 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=Two+waves+of+distinct+hematopoietic+progenitor+cells+colonize+the+fetal+thymus.">Two waves of distinct hematopoietic progenitor cells colonize the fetal thymus.</a> Nat Immunol. 15, 27-35 (2014).</li><li>Allison, J. P., Havran, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+immunobiology+of+T+cells+with+invariant+gamma+delta+antigen+receptors.">The immunobiology of T cells with invariant gamma delta antigen receptors.</a> Annu Rev Immunol. 9, 679-705 (1991).</li><li>Anderson, G., Jenkinson, 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=Fetal+thymus+organ+culture.">Fetal thymus organ culture.</a> CSH Protoc. , (2007).</li><li>Schmitt, T. M., Zuniga-Pflucker, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+T+cell+development+from+hematopoietic+progenitor+cells+by+delta-like-1+in+vitro.">Induction of T cell development from hematopoietic progenitor cells by delta-like-1 in vitro.</a> Immunity. 17, 749-756 (2002).</li><li>Barbee, S. D., 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=Skint-1+is+a+highly+specific,+unique+selecting+component+for+epidermal+T+cells.">Skint-1 is a highly specific, unique selecting component for epidermal T cells.</a> Proc Natl Acad Sci U S A. 108, 3330-3335 (2011).</li><li>Douagi, I., Colucci, F., Di Santo, J. 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تعلن الكتاب أنه ليس لديهم المصالح المالية المتنافسة.

تحليلين الرئيسية يمكن استخدامها لتحليل T تمايز الخلايا خارج الجسم الحي. الأكثر ذكرت مؤخرا هو شريك في ثقافة الأسلاف المكونة للدم مع خلايا انسجة BM، OP9، معربا عن بروابط من Noth1، دلتا مثل 1 أو 4 12. هذا الاختبار 2-D من السهل القيام بها، كفاءة عالية وحساسية، مما يسمح ل...

اللمفاويات التائية، التي تحمل αβ أو γδ الخلايا التائية مستقبلات (TCR)، تفرق في جهاز متخصص، والغدة الصعترية. ويتم تنظيم الغدة الصعترية كاملة النمو إلى منطقتين متميزتين: القشرة، حيث تتطور الأسلاف الغدة الصعترية، وحيث يتم إنقاذ thymocytes أن إعادة ترتيب الخلاق للβ TCR والجينات سلسلة α من الموت المبرمج (وهي عملية تعرف باسم الانتقاء الإيجابية)؛ والنخاع، حيث المختارة thymocytes مع تفاعل قوي جدا لبروابط الذاتي يتم حذف (اختيار السلبية) 1،2. الغدة الصعترية تنبع من طبقة الأديم الباطن من الحقيبة البلعوم الثالثة التي تحيط وقت لاحق من خلايا اللحمة المتوسطة 3. واستعمرت من قبل الأسلاف المكونة للدم ابتداء من يوم الجنينية E12، وبعد ذلك مطلوب التوظيف المستمر لT العادي تطوير خلية 4. المهاجرين الغدة الصعترية تتطور من خلال مراحل النمو المتعاقبة، مدبرة من قبل برنامج منظم بإحكام، بدأت ومايو ntained من خلال تفعيل إشارات المسار الشق على thymocytes على التفاعل مع يجند لها، مثل دلتا 4، أعرب عن الخلايا الظهارية الغدة الصعترية (TECS) 5. تبدأ تطوير خلية توتية في ما يسمى CD4 - CD8 - النفي المزدوج (DN) مراحل. thymocytes DN يمكن تقسيم كذلك وفقا لتعبير عن CD25 CD44 وإلى DN1 (CD25 - CD44 +)، DN2 (CD25 + CD44 +)، DN3 (CD25 + CD44 -) وDN4 (CD25 - CD44 -). CD24 (هائل سعيد أنعم) وCD117 (ج كيت) يقسم كذلك مقصورة DN1 إلى 5 مجموعات فرعية حيث DN1a وب تتوافق مع الأسلاف الغدة الصعترية في وقت مبكر (ETP). Thymocytes إعادة ترتيب TCR δ، β α والسلاسل في مرحلة DN وتخضع قبل TCR اختيار (مراحل DN3-DN4). انهم عبور أخرى إلى CD4 + CD8 + إيجابية مزدوج (DP) حجرة حيث تعيد ترتيب سلسلة α TCR قبل سيلي الإيجابية والسلبيةction. في هذه المرحلة يتم استبعاد معظم thymocytes وفقط نسبة صغيرة (3-5٪) تصل إلى CD4 + أو CD8 + T مقصورة تنضج الخلية. تمايز مسار اللمفاوية تقدم من خلال مراحل HSCs التي تولد الأسلاف متعدد القدرات (MPP) والأسلاف معبي اللمفاوية متعددة القدرات (LMPP) التي فقدت كرات الدم الحمراء والنواء المحتملين 6. يتم تعريف LMPP ظاهريا بسبب عدم وجود علامات خلايا الدم متباينة (النسب السلبية، لين -)، والتعبير عن ج-كيت (CD117)، هيئة السلع التموينية، 1 وFlt3 / Flk2 (CD135) وعدم وجود مستويات ملحوظة من انترلوكين ( IL) -7 مستقبلات α سلسلة (IL-7rα أو CD127). LMPPs تمييز الى مزيد من الأسلاف المشتركة اللمفاوية (CLP) 7 أنه من خلال تلك المرحلة قد فقدت القدرة على توليد خلايا الدم النخاعي. CLP الاحتفاظ الخلايا اللمفاوية (B والخلايا التائية)، الخلايا القاتلة الطبيعية، DC والخلايا اللمفاوية الفطرية (ILC) المحتملة، وتختلف عن LMPP عن طريق التعبير عن CD127 وعدم وجود مستويات عالية من هيئة السلع التموينية-1. على الرغم من أن طبيعة التوتة تسوية الأسلاف (TSP) قد نوقشت على نطاق واسع 8، أصبح من الواضح مؤخرا أن تغيير النمط الظاهري TSP، إمكانية التمايز وظيفة، في جميع أنحاء تنمية 9. أجرينا في التجارب المختبرية وفحوصات الجسم الحي لتوصيف TSP المعزولة FACS الخلية الفرز من أي E13 (الموجة الأولى) أو E18 (الموجة الثانية). الجنين الثقافات الجهاز الغدة الصعترية (FTOC) مع فصوص الغدة الصعترية المشع مستعمرة من قبل أعداد متساوية من E13 E18 والأسلاف، واضعا علامات النمط الخيفي مختلفة، سمح التالية ذريتهم في بيئة تنموية مماثلة وكشف خلية الخصائص الجوهرية، مختلفة بين كلا النوعين من الأسلاف. فصوص الغدة الصعترية التي استعمرتها إما E13 أو E18 TSP سمحت تنمية دون انتقاء بسبب المنافسة بين كل من الأسلاف. أظهر في الجسم الحي زرع فصوص الغدة الصعترية المستعمرة كذلك أن أيضا رانه ذرية ناضجة من E13 E18 وTSP دينا مختلف الخصائص البيولوجية في الجسم الحي. TSPs من الموجة الأولى تولد بسرعة خلايا T ولكن تؤدي إلى انخفاض أعداد αβ وγδ الخلايا التائية. بين هذا الأخير اكتشفنا Vγ5Vδ1 الخلايا الجذعية الظهارية T (DETC)، التي لها TCR ثابتة، تهاجر إلى البشرة حيث تمارس وظيفة في التئام الجروح ويتم إنتاجها فقط أثناء التطور الجنيني 10. في المقابل، TSP من الموجة الثانية يستغرق وقتا أطول لتوليد أعداد كبيرة من الخلايا TCR + T وغير قادر على توليد DETC.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>90 x 15 mm and 35 x 15 mm plastic tissue culture petri dishes.</td>
			<td>TPP</td>
			<td>T93100/T9340</td>
			<td>Sampling</td>
		</tr>
		<tr>
			<td>26GA 3/8 IN 0.45x10mm syringes with needles Beckton-Dickinson Plastipak.</td>
			<td>BD Plastipak</td>
			<td>300015</td>
			<td>Cell suspension</td>
		</tr>
		<tr>
			<td>Nylon mesh bolting cloth sterilized 50/50 mm pieces.</td>
			<td>SEFAR NITEX</td>
			<td>03-100/32</td>
			<td>Filtration of cells</td>
		</tr>
		<tr>
			<td>Ethanol 70%.</td>
			<td>VWR</td>
			<td>83801.36</td>
			<td>Sterility Actions</td>
		</tr>
		<tr>
			<td>Iodide Povidone 10% (Betadine)&#160;</td>
			<td>MEDA Pharma</td>
			<td>314997.8</td>
			<td>Sterility Actions</td>
		</tr>
		<tr>
			<td>Ketamine 100mg/ml (stock solution)</td>
			<td>MERIAL</td>
			<td>&#160;-</td>
			<td>Anesthesic</td>
		</tr>
		<tr>
			<td>Xylazine 100mg/ml in PBS (stock solution)</td>
			<td>Sigma</td>
			<td>X1251-1G</td>
			<td>Anesthesic and muscle relaxant</td>
		</tr>
		<tr>
			<td>Buprenorphin 0.3mg/ml stock solution</td>
			<td>AXIENCE</td>
			<td>&#160;-</td>
			<td>Morphinic analgesic</td>
		</tr>
		<tr>
			<td>Ophtalmic gel (0.2% cyclosporin)</td>
			<td>Schering-Plough Animal Health</td>
			<td>&#160;-</td>
			<td>Eyes protection</td>
		</tr>
		<tr>
			<td>DPBS (+ CaCl2, MgCl2)</td>
			<td>GIBCO Life Technology</td>
			<td>14040-174</td>
			<td>to isolate embryos</td>
		</tr>
		<tr>
			<td>HBSS Hanks&#39; Balanced Salt Solution (+ CaCl2, MgCl2)</td>
			<td>GIBCO Life Technology</td>
			<td>24020-091</td>
			<td>to wash out the blood and dissect the embryos</td>
		</tr>
		<tr>
			<td>OPTI-MEM I GlutaMAX I</td>
			<td>GIBCO Life Technology</td>
			<td>51985-026</td>
			<td>Medium for cultures</td>
		</tr>
		<tr>
			<td>F&#339;tal Calf serum</td>
			<td>EUROBIO</td>
			<td>CVFSVF00-0U</td>
			<td>additive for cultures</td>
		</tr>
		<tr>
			<td>Penicilin and Streptomycin</td>
			<td>GIBCO Life Technology</td>
			<td>15640-055</td>
			<td>Antibiotics for cultures</td>
		</tr>
		<tr>
			<td>2 b mercapto ethanol</td>
			<td>GIBCO Life Technology</td>
			<td>31350010</td>
			<td>additive for cultures</td>
		</tr>
		<tr>
			<td>LEICA MZ6 Dissection microscope</td>
			<td>LEICA</td>
			<td>MZ6 10445111</td>
			<td>Occular W-Pl10x/23</td>
		</tr>
		<tr>
			<td>Cold lamp source</td>
			<td>SCHOTT VWR</td>
			<td>KL1500 compact</td>
			<td>Two goose neck fibers adapted</td>
		</tr>
		<tr>
			<td>Silicone elastomer</td>
			<td>World Precision Instruments</td>
			<td>SYLG184</td>
			<td>Dissecting Pad</td>
		</tr>
		<tr>
			<td>Spoon, round and perforated</td>
			<td>Fine Science Tools</td>
			<td>10370-18</td>
			<td>Dissection tools</td>
		</tr>
		<tr>
			<td>Fine Iris Scissors</td>
			<td>Fine Science Tools</td>
			<td>14090-09</td>
			<td>Dissection tools</td>
		</tr>
		<tr>
			<td>Vannas spring Scissors</td>
			<td>Fine Science Tools</td>
			<td>15018-10</td>
			<td>Dissection tools</td>
		</tr>
		<tr>
			<td>Forceps : Dumont #5/45 Inox 11 cm</td>
			<td>F.S.T.</td>
			<td>11253-25</td>
			<td>Dissection tools</td>
		</tr>
		<tr>
			<td>Two pairs of fine straight watchmakers&#8217; forceps Dumont #5 11 cm fine tips.</td>
			<td>Fine Science Tools</td>
			<td>11295-20</td>
			<td>Dissection tools</td>
		</tr>
		<tr>
			<td>Polyamid thread with needle 6-0&#160;&#160; C-3 3/8c</td>
			<td>ETHICON</td>
			<td>F2403</td>
			<td>for sutures</td>
		</tr>
		<tr>
			<td>Needle-holder</td>
			<td>MORIA/F.S.T.</td>
			<td>12060-02</td>
			<td>for sutures</td>
		</tr>
		<tr>
			<td>Heating pad</td>
			<td>VWR</td>
			<td>100229-100</td>
			<td>To maintain mouse temperature during anesthesy</td>
		</tr>
		<tr>
			<td>Membrane Isopore RTTPO2500</td>
			<td>DUTSCHER</td>
			<td>44210</td>
			<td>For FTOC</td>
		</tr>
		<tr>
			<td>Terasaki 60 wells plates</td>
			<td>FISHER</td>
			<td>1x270 10318801</td>
			<td>For hanging drop technique</td>
		</tr>
		<tr>
			<td>Gauze swabs steriles 7.5cmx7.5cm</td>
			<td>Hydrex</td>
			<td>11522</td>
			<td>To apply disinfecting solution</td>
		</tr>
		<tr>
			<td>Fluorescence or biotin labelled antibodies</td>
			<td>BD Biosciences, Biolegend or e-Biocsiences&#160;</td>
			<td>Clone Number see table below</td>
			<td>Staining cells</td>
		</tr>
		<tr>
			<td>MACS Columns/Streptavidin Microbeads&#160;</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-401/130-048-101</td>
			<td>Cell depletion&#160;</td>
		</tr>
		<tr>
			<td>Mice</td>
			<td>Charles Rivers Laboratories (CD45.1) and Janvier Labs&#160; (CD45.2)</td>
			<td>C57BL/6 CD45.1 OR CD45.2</td>
			<td>Source of cells and thymic lobes&#160;</td>
		</tr>
		<tr>
			<td>Mice</td>
			<td>CDTA Orl&#233;ans, France</td>
			<td>CD 3 epsilon Ko CD45.2</td>
			<td>&#160;Grafting experiment</td>
		</tr>
	</tbody>
</table>

characterization of thymic settling progenitors in the mouse embryo using in vivo and in vitro assays

تميز التوتة تسوية الأسلاف من المهم أن نفهم مراحل ما قبل الغدة الصعترية التنمية الخلايا T، ضرورية لوضع استراتيجيات لT استبدال الخلايا في المرضى الذين يعانون lymphopenic. درسنا التوتة تسوية الأسلاف من الفئران الجنينية يوم 13 و 18 التوتة من قبل اثنين من تكميلي في المختبر وتقنيات الجسم الحي، سواء على أساس &quot;شنقا قطرة&quot; الأسلوب. يسمح هذا الأسلوب استعمار المشع فصوص الغدة الصعترية الجنين مع E13 و / أو E18 الأسلاف الغدة الصعترية تتميز CD45 علامات النمط الخيفي وبالتالي التالية ذريتها. الاستعمار المختلطة السكان يسمح تحليل الخلايا الخلافات الحكم الذاتي في خصائص بيولوجية من الأسلاف في حين الاستعمار سواء مع السكان يزيل ضغوط انتقائية تنافسية الممكنة. ويمكن أيضا أن فصوص الغدة الصعترية المستعمر أن المطعمة في الفئران المتلقي الذكور العوز المناعي يسمح للتحليل ناضجة الخلايا التائية ذرية في الجسم الحي، مثل ديناميات السكان رانه الطرفية جهاز المناعة، واستعمار الأنسجة والأعضاء المختلفة. كشفت الجنين الثقافات الجهاز الغدة الصعترية أن الأسلاف E13 تطورت بسرعة في جميع تنضج CD3 + الخلايا، وأدت إلى الكنسي فرعية الخلايا T γδ، والمعروفة باسم خلايا T الظهارية الجذعية. في المقابل، الأسلاف E18 لها تمايز وتأخر وكانت قادرة على توليد خلايا الظهارية T الجذعية. وأظهرت الفئران أيضا أن الأسلاف E18 التوتة تسوية تولد، مع مرور الوقت، أعداد أكبر من الخلايا الناضجة T من نظرائهم E13، وهي الميزة التي لا يمكن تقديره في التوتة الجنين على المدى القصير - رصد الدم المحيطي من المطعمة الغدة الصعترية CD3 - / ثقافات الجهاز.

من أجل اختيار طريقة لاستنزاف فصوص الغدة الصعترية من thymocytes الذاتية السماح للأفضل تطوير الأسلاف استعمار، قارنا مستويات T إعادة خلية في فصوص الغدة الصعترية المستعمر بعد التشعيع أو 5 أيام ديوكسي-غوانوزين (د-غواتيمالا) العلاج. أظهرت النتائج أنه في حين لا يوجد فرق في يوم 9 م...

Watch this Scientific Journal Video about Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays at JoVE.com

Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays

This article describes in vivo and in vitro methodology to characterize the thymic settling progenitors by the analysis of the kinetics of generation, phenotype and numbers of their T cell progeny.

توصيف التوتة تسوية الأسلاف في جنين الفأر عن طريق<em&gt; في فيفو</em&gt; و<em&gt; في المختبر</em&gt; فحوصات

Characterizing thymic settling progenitors is important to understand the pre-thymic stages of T cell development, essential to devise strategies for T ...

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Developmental Biology

Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays

8.2K Views.  Institut Cochin. This article describes in vivo and in vitro methodology to characterize the thymic settling progenitors by the analysis of the kinetics of generation, phenotype and numbers of their T cell progeny. 

Video: Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays

Directed Differentiation of Primitive and Definitive Hematopoietic Progenitors from Human Pluripotent Stem Cells

One of the major goals for regenerative medicine is the generation and maintenance of hematopoietic stem cells (HSCs) derived from human pluripotent stem cells (hPSCs). Until recently, efforts to differentiate hPSCs into HSCs have predominantly generated hematopoietic progenitors that lack HSC potential, and instead resemble yolk sac hematopoiesis.&#160;These resulting hematopoietic progenitors may have limited utility for in vitro disease modeling of various adult hematopoietic disorders, particularly those of the lymphoid lineages. However, we have recently described methods to generate erythro-myelo-lymphoid multilineage definitive hematopoietic progenitors from hPSCs using a stage-specific directed differentiation protocol, which we outline here. Through enzymatic dissociation of hPSCs on basement membrane matrix-coated plasticware, embryoid bodies (EBs) are formed. EBs are differentiated to mesoderm by recombinant BMP4, which is subsequently specified to the definitive hematopoietic program by the GSK3&#946; inhibitor, CHIR99021. Alternatively, primitive hematopoiesis is specified by the PORCN inhibitor, IWP2. Hematopoiesis is further driven through the addition of recombinant VEGF and supportive hematopoietic cytokines. The resulting hematopoietic progenitors generated using this method have the potential to be used for disease and developmental modeling, in vitro.

Here, we present human pluripotent stem cell (hPSC) culture protocols, used to differentiate hPSCs into CD34+ hematopoietic progenitors. This method uses stage-specific manipulation of canonical WNT signaling to specify cells exclusively to either the definitive or primitive hematopoietic program.

وجه التفريق بين فروعه المكونة للدم البدائي والنهائي من الخلايا الجذعية Pluripotent البشرية

One of the major goals for regenerative medicine is the generation and maintenance of hematopoietic stem cells (HSCs) derived from human pluripotent stem ...

Identification Of Erythromyeloid Progenitors And Their Progeny In The Mouse Embryo By Flow Cytometry

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where they act as front line sentinels of infection and tissue damage. While other immune cells are continuously renewed from hematopoietic stem and progenitor cells (HSPC) located in the bone marrow, a lineage of macrophages, known as resident macrophages, have been shown to be self-maintained in tissues without input from bone marrow HSPCs. This lineage is exemplified by microglia in the brain, Kupffer cells in the liver and Langerhans cells in the epidermis among others. The intestinal and colon lamina propria are the only adult tissues devoid of HSPC-independent resident macrophages. Recent investigations have identified that resident macrophages originate from the extra-embryonic yolk sac hematopoiesis from progenitor(s) distinct from fetal hematopoietic stem cells (HSC). Among yolk sac definitive hematopoiesis, erythromyeloid progenitors (EMP) give rise both to erythroid and myeloid cells, in particular resident macrophages. EMP are only generated within the yolk sac between E8.5 and E10.5 days of development and they migrate to the fetal liver as early as circulation is connected, where they expand and differentiate until at least E16.5. Their progeny includes erythrocytes, macrophages, neutrophils and mast cells but only EMP-derived macrophages persist until adulthood in tissues. The transient nature of EMP emergence and the temporal overlap with HSC generation renders the analysis of these progenitors difficult. We have established a tamoxifen-inducible fate mapping protocol based on expression of the macrophage cytokine receptor Csf1r promoter to characterize EMP and EMP-derived cells in vivo by flow cytometry.

While infiltrating macrophages are continuously recruited to adult tissues from circulating precursors, resident macrophages seed their tissue during development, where they are maintained without further input from progenitors. The progenitors for resident macrophages were recently identified. Here, we present methods for the genetic fate mapping of the resident macrophage progenitors.

تحديد أسلاف ريدثروميلويد وذريتهم في الجنين الماوس عن طريق التدفق الخلوي

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where ...

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced in vivo throughout the rapid developmental period. Multiple processes can be studied including cell proliferation, gene expression, cell migration and morphogenesis. Importantly, the generation of chimeras through transplantations can be easily performed, allowing mosaic labeling and tracking of individual cells under the influence of the host environment. For example, by combining functional gene manipulations of the host embryo (e.g., through morpholino microinjection) and live imaging, the effects of extrinsic, cell nonautonomous signals (provided by the genetically modified environment) on individual transplanted donor cells can be assessed. Here we demonstrate how this approach is used to compare the onset of fluorescent transgene expression as a proxy for the timing of cell fate determination in different genetic host environments.
In this article, we provide the protocol for microinjecting zebrafish embryos to mark donor cells and to cause gene knockdown in host embryos, a description of the transplantation technique used to generate chimeric embryos, and the protocol for preparing and running in vivo time-lapse confocal imaging of multiple embryos. In particular, performing multiposition imaging is crucial when comparing timing of events such as the onset of gene expression. This requires data collection from multiple control and experimental embryos processed simultaneously. Such an approach can easily be extended for studies of extrinsic influences in any organ or tissue of choice accessible to live imaging, provided that transplantations can be targeted easily according to established embryonic fate maps.

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

Live tracking of individual WT retinal progenitors in distinct genetic backgrounds allows for the assessment of the contribution of cell non-autonomous signaling during neurogenesis. Here, a combination of gene knockdown, chimera generation via embryo transplantation and in vivo time-lapse confocal imaging was utilized for this purpose.

في فيفو التصوير التعبير المعدلة وراثيا الجينات في الفرد الشبكية الأسلاف في الجنين اسماك الزرد همي لدراسة الخلية التأثيرات Nonautonomous

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced ...

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the proteins involved in these pathways are evolutionarily conserved between mammals and other eukaryotes, such as the fruit fly Drosophila melanogaster, suggesting that similar organizing principles exist during the development of these organisms. Importantly, Drosophila has been used extensively to identify cellular and molecular mechanisms regulating processes that are required in mammals including neurogenesis, differentiation, axonal guidance, and synaptogenesis. Flies have also been used successfully to model a variety of human neurodevelopmental diseases. Here we describe a protocol for the step-by-step microdissection, fixation, and immunofluorescent localization of proteins within the adult Drosophila brain. This protocol focuses on two example neuronal populations, mushroom body neurons and retinal photoreceptors, and includes optional steps to trace individual mushroom body neurons using Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. Example data from both wild-type and mutant brains are shown along with a brief description of a scoring criteria for axonal guidance defects. While this protocol highlights two well-established antibodies for investigating the morphology of mushroom body and photoreceptor neurons, other Drosophila brain regions and the localization of proteins within other brain regions can also be investigated using this protocol.

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

This protocol describes the dissection and immunostaining of adult Drosophila melanogaster brain tissues. Specifically, this protocol highlights the use of Drosophila mushroom body and photoreceptor neurons as example neuronal subsets that can be accurately used to uncover general principles underlying many aspects of neuronal development.

تشريح وتلطيخ إيممونوفلوريسسينت للفطر الجسم وعلم الخلايا العصبية في أدمغة البالغين melanogaster المورفولوجية

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands

Notch signaling is an evolutionarily conserved cell-cell communication system used broadly in animal development and adult maintenance. Interaction of the Notch receptor with ligands from neighboring cells induces activation of the signaling pathway (trans-activation), while interaction with ligands from the same cell inhibits signaling (cis-inhibition). Proper balance between trans-activation and cis-inhibition helps establish optimal levels of Notch signaling in some contexts during animal development. Because of the overlapping expression domains of Notch and its ligands in many cell types and the existence of feedback mechanisms, studying the effects of a given post-translational modification on trans- versus cis-interactions of Notch and its ligands in vivo is difficult. Here, we describe a protocol for using Drosophila S2 cells in cell-aggregation assays to assess the effects of knocking down a Notch pathway modifier on the binding of Notch to each ligand in trans and in cis. S2 cells stably or transiently transfected with a Notch-expressing vector are mixed with cells expressing each Notch ligand (S2-Delta or S2-Serrate). Trans-binding between the receptor and ligands results in the formation of heterotypic cell aggregates and is measured in terms of the number of aggregates per mL composed of &#62;6 cells. To examine the inhibitory effect of cis-ligands, S2 cells co-expressing Notch and each ligand are mixed with S2-Delta or S2-Serrate cells and the number of aggregates is quantified as described above. The relative decrease in the number of aggregates due to the presence of cis-ligands provides a measure of cis-ligand-mediated inhibition of trans-binding. These straightforward assays can provide semi-quantitative data on the effects of genetic or pharmacological manipulations on the binding of Notch to its ligands, and can help deciphering the molecular mechanisms underlying the in vivo effects of such manipulations on Notch signaling.

Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands

Complexity of in vivo systems makes it difficult to distinguish between the activation and inhibition of Notch receptor by trans- and cis-ligands, respectively. Here, we present a protocol based on in vitro cell-aggregation assays for qualitative and semi-quantitative evaluation of the binding of Drosophila Notch to trans-ligands vs cis-ligands.

خلية "التجميع فحوصات" لتقييم ربط الشق المورفولوجية مع ترانس-يغاندس وتثبيط عن طريق رابطة الدول المستقلة-يغاندس

Notch signaling is an evolutionarily conserved cell-cell communication system used broadly in animal development and adult maintenance. Interaction of the ...

Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro

The pancreas is a complex organ composed of many different cell types that work together to regulate blood glucose homeostasis and digestion. These cell types include enzyme-secreting acinar cells, an arborized ductal system responsible for the transportation of enzymes to the gut, and hormone-producing endocrine cells. 
Endocrine beta-cells are the sole cell type in the body that produce insulin to lower blood glucose levels. Diabetes, a disease characterized by a loss or the dysfunction of beta-cells, is reaching epidemic proportions. Thus, it is essential to establish protocols to investigate beta-cell development that can be used for screening purposes to derive the drug and cell-based therapeutics. While the experimental investigation of mouse development is essential, in vivo studies are laborious and time-consuming. Cultured cells provide a more convenient platform for screening; however, they are unable to maintain the cellular diversity, architectural organization, and cellular interactions found in vivo. Thus, it is essential to develop new tools to investigate pancreatic organogenesis and physiology.
Pancreatic epithelial cells develop in the close association with mesenchyme from the onset of organogenesis as cells organize and differentiate into the complex, physiologically competent adult organ. The pancreatic mesenchyme provides important signals for the endocrine development, many of which are not well understood yet, thus difficult to recapitulate during the in vitro culture. Here, we describe a protocol to culture three-dimensional, cellular complex mouse organoids that retain mesenchyme, termed pancreatoids. The e10.5 murine pancreatic bud is dissected, dissociated, and cultured in a scaffold-free environment. These floating cells self-assemble with mesenchyme enveloping the developing pancreatoid and a robust number of endocrine beta-cells developing along with the acinar and the duct cells. This system can be used to study the cell fate determination, structural organization, and morphogenesis, cell-cell interactions during organogenesis, or for the drug, small molecule, or genetic screening.

Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro

Here, we present a protocol to generate insulin expressing 3D murine pancreatoids from free-floating e10.5 dissociated pancreatic progenitors and the associated mesenchyme.

جيل بانكريتويدس التعبير عن الأنسولين خالية من السقالة، ثلاثي الأبعاد من الماوس المتكفل البنكرياس في المختبر

The pancreas is a complex organ composed of many different cell types that work together to regulate blood glucose homeostasis and digestion. These cell ...

Visualizing the Node and Notochordal Plate In Gastrulating Mouse Embryos Using Scanning Electron Microscopy and Whole Mount Immunofluorescence

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is the formation of the transient organizers, the node and notochordal plate, from cells that have passed through the primitive streak. The proper formation of these signaling centers is essential for the development of the body plan and techniques to visualize them are of high interest to mouse developmental biologists. The node and notochordal plate lie on the ventral surface of gastrulating mouse embryos around embryonic day (E) 7.5 of development. The node is a cup-shaped structure whose cells possess a single slender cilium each. The proper subcellular localization and rotation of the cilia in the node pit determines left-right asymmetry. The notochordal plate cells also possess single cilia albeit shorter than those of the node cells. The notochordal plate forms the notochord which acts as an important signaling organizer for somitogenesis and neural patterning. Because the cells of the node and notochordal plate are transiently present on the surface and possess cilia, they can be visualized using scanning electron microscopy (SEM). Among other techniques used to visualize these structures at the cellular level is whole mount immunofluorescence (WMIF) using the antibodies against the proteins that are highly expressed in the node and notochordal plate. In this report, we describe our optimized protocols to perform SEM and WMIF of the node and notochordal plate in developing mouse embryos to help in the assessment of tissue shape and cellular organization in wild-type and gastrulation mutant embryos.

The node and notochordal plate are transient signaling organizers in developing mouse embryos that can be visualized using several techniques. Here, we describe in detail how to perform two of the techniques to study their structure and morphogenesis: 1) scanning electron microscopy (SEM); and 2) whole mount immunofluorescence (WMIF).

تصور بالعقدة ولوحة نوتوتشوردال في جاسترولاتينج الأجنة الماوس باستخدام الميكروسكوب الإلكتروني المسح وكله جبل الفلورة

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is ...

Microinjection-based System for In Vivo Implantation of Embryonic Cardiomyocytes in the Avian Embryo

Interpreting the relative impact of cell autonomous patterning versus extrinsic microenvironmental influence on cell lineage determination represents a general challenge in developmental biology research. In the embryonic heart, this can be particularly difficult as regional differences in the expression of transcriptional regulators, paracrine/juxtacrine signaling cues, and hemodynamic force are all known to influence cardiomyocyte maturation. A simplified method to alter a developing cardiomyocyte's molecular and biomechanical microenvironment would, therefore, serve as a powerful technique to examine how local conditions influence cell fate and function. To address this, we have optimized a method to physically transplant juvenile cardiomyocytes into ectopic locations in the heart or the surrounding embryonic tissue. This allows us to examine how microenvironmental conditions influence cardiomyocyte fate transitions at single cell resolution within the intact embryo. Here, we describe a protocol in which embryonic myocytes can be isolated from a variety of cardiac sub-domains, dissociated, fluorescently labeled, and microinjected into host embryos with high precision. Cells can then be directly analyzed in situ using a variety of imaging and histological techniques. This protocol is a powerful alternative to traditional grafting experiments that can be prohibitively difficult in a moving tissue such as the heart. The general outline of this method can also be adapted to a variety of donor tissues and host environments, and its ease of use, low cost, and speed make it a potentially useful application for a variety of developmental studies.

In this method, embryonic cardiac tissues are surgically microdissected, dissociated, fluorescently labeled, and implanted into host embryonic tissues. This provides a platform for studying the individual or tissue level developmental organization under ectopic hemodynamic conditions, and/or altered paracrine/juxtacrine environments.

النظام القائم على microinjection لفي غرس فيفو Cardiomyocytes الجنينية في جنين الطيور

Interpreting the relative impact of cell autonomous patterning versus extrinsic microenvironmental influence on cell lineage determination represents a ...

Differentiation and Characterization of Neural Progenitors and Neurons from Mouse Embryonic Stem Cells

We describe the step-by-step procedure for culturing and differentiating mouse embryonic stem cells into neuronal lineages, followed by a series of assays to characterize the differentiated cells. The E14 mouse embryonic stem cells were used to form embryoid bodies through the hanging drop method, and then induced to differentiate into neural progenitor cells by retinoic acid, and finally differentiated into neurons. Quantitative&#160;reverse transcription&#160;polymerase chain reaction (RT-qPCR) and immunofluorescence experiments revealed that the neural progenitors and neurons exhibit corresponding markers (nestin for neural progenitors and neurofilament for neurons) at day 8 and 12 post-differentiation, respectively. Flow cytometry experiments on an E14 line expressing a Sox1 promoter-driven GFP reporter showed that about 60% of cells at day 8 are GFP positive, indicating the successful differentiation of neural progenitor cells at this stage. Finally, RNA-seq analysis was used to profile the global transcriptomic changes. These methods are useful for analyzing the involvement of specific genes and pathways in regulating the cell identity transition during neuronal differentiation.

We describe the procedure for the in vitro differentiation of mouse embryonic stem cells into neuronal cells using the hanging drop method. Furthermore, we perform a comprehensive phenotypic analysis through RT-qPCR, immunofluorescence, RNA-seq, and flow cytometry.

التمايز وتوصيف السلف العصبية والخلايا العصبية من الخلايا الجذعية الجنينية الماوس

We describe the step-by-step procedure for culturing and differentiating mouse embryonic stem cells into neuronal lineages, followed by a series of assays ...

Spatiotemporal Subcellular Manipulation of the Microtubule Cytoskeleton in the Living Preimplantation Mouse Embryo using Photostatins

The microtubule cytoskeleton forms the framework of a cell and is fundamental for intracellular transport, cell division, and signal transduction. Traditional pharmacological disruption of the ubiquitous microtubule network using, for instance, nocodazole can have devastating consequences for any cell. Reversibly photoswitchable microtubule inhibitors have the potential to overcome the limitations by enabling drug effects to be implemented in a spatiotemporally-controlled manner. One such family of drugs is the azobenzene-based photostatins (PSTs). These compounds are inactive in dark conditions, and upon illumination with UV light, they bind to the colchicine-binding site of &#946;-tubulin and block microtubule polymerization and dynamic turnover. Here, the application of PSTs in the 3-dimensional (3D) live preimplantation mouse embryo is set out to disrupt the microtubule network on a subcellular level. This protocol provides instructions for the experimental setup, as well as light activation and deactivation parameters for PSTs using live-cell confocal microscopy. This ensures reproducibility and enables others to apply this procedure to their research questions. Innovative photoswitches like PSTs may evolve as powerful tools to advance the understanding of the dynamic intracellular microtubule network and to non-invasively manipulate the cytoskeleton in real-time. Furthermore, PSTs may prove useful in other 3D structures such as organoids, blastoids, or embryos of other species.

Typical microtubule inhibitors, used widely in basic and applied research, have far-reaching effects on cells. Recently, photostatins emerged as a class of photoswitchable microtubule inhibitors, capable of instantaneous, reversible, spatiotemporally precise manipulation of microtubules. This step-by-step protocol details the application of photostatins in a 3D live preimplantation mouse embryo.