This work was supported by funding received from the National Institutes of Health (1R01AI083269).

Gli studi murini sono stati approvati dalla cura e l&#39;uso Comitato Istituzionale Animal (IACUC) della University of North Carolina a Chapel Hill e tutte le cure degli animali era in conformità con le linee guida IACUC. 1. Preparazione del neonato e Adult Thymi <ol><li> Preparare tutti i reagenti e le attrezzature prima di eutanasia topi donatori. </li><li> Sterilizzare gli strumenti chirurgici in autoclave o altri metodi appropriati. Tutte le procedure chirurgiche sono svolte sotto una cappa a flusso laminare per mantenere condizioni sterili ed evitare la contaminazione. Montare gli strumenti necessari per l&#39;estrazione di thymi da topi donatori. </li><li> Riempire piastre da 60 mm sterile 1x PBS (pH 7.4) e disporli sul ghiaccio all&#39;interno della cappa. Questo verrà utilizzato per memorizzare brevemente thymi asportato da topi donatori prima del trapianto. </li><li> Come da orientamenti etici, eutanasia topi donatori neonati per decapitazione e donatori adulti topi da CO 2 asfissia seguita da dislocazione cervicale. </li><li> Per removal del timo: Appoggiare il mouse in una posizione reclinata dorsale su un tovagliolo di carta assorbente sterile e spruzzare con il 70% di etanolo prima di effettuare una incisione. </li><li> Esporre la cavità addominale e toracica facendo un&#39;incisione mediana attraverso la pelle. Piegare la pelle sul petto e zampe anteriori per rivelare la cavità toracica. </li><li> Fare due incisioni laterali attraverso il diaframma e gabbia toracica per esporre il mediastino superiore e anteriore cavità toracica. Il timo deve essere visibile come due lobi bianche immediatamente sopra e adiacente al cuore. </li><li> Tease a parte il tessuto connettivo circostante il timo con una pinza sottile, facendo attenzione a non interrompere la capsula. Mentre trattenendo la gabbia toracica con una pinza, utilizzare una seconda coppia di pinze per estrarre i due lobi del timo posizionando pinze curve sotto l&#39;organo e tirando verticalmente. Questo può essere fatto utilizzando un ambito dissezione per estrarre thymi da topi appena nati. </li><li> Posizionare il timo in 60 millimetri dish contenente sterile 1x PBS (pH 7.4) su ghiaccio e lobi del timo separati tagliando attraverso l&#39;istmo connettivo. Rimuovere eventuali detriti dai lobi del timo facendo attenzione a non danneggiare la capsula, e tagliare il timo nel numero appropriato di sezioni per il trapianto. </li><li> Non manipolare il thymi ottenuto da topi appena nati. NOTA: Utilizzato per un massimo di due topi riceventi (1 lobo per destinatario). </li><li> Transplant il thymi ottenuto da topi adulti in un massimo di 4-6 topi riceventi. Utilizzando un paio di pinze, afferrare accuratamente un adulto lobo timico, come mostrato nella Figura 1, tagliare il timo in tre sezioni uguali utilizzando forbici chirurgiche. </li><li> Ripetere i passaggi 1,3-1,4 per ogni mouse donatore. Al fine di limitare il tempo thymi sono esposti, preparare timo 1 donatore alla volta. </li></ol> 2. Timo impianto sotto la capsula renale <ol><li> Montare l&#39;apparecchiatura pre-sterilizzato elencati nella Tabella 1. Asettica Propertecnica dovrebbe essere utilizzata nel corso della procedura per evitare l&#39;esposizione trapianto destinatari di strumenti o reagenti contaminati. </li><li> Prima del trapianto, pesare ed etichettare ogni mouse destinatario. </li><li> Impostare il microscopio da dissezione e circuito di anestesia nella cappa a flusso laminare. </li><li> Usando un rasoio elettrico, radere il lato sinistro del mouse destinatario e non assicurano capelli rimangono intorno all&#39;area utilizzata per effettuare l&#39;incisione. </li><li> Accendere vaporizzatore isofluorane e anestetizzare il mouse utilizzando una dose compresa tra 1-2%. Accertare corretta anesthetization prima di avviare la procedura chirurgica verificando l&#39;assenza di riflesso seguente pinch punta. </li><li> Dopo il mouse viene adeguatamente anestetizzato, applicare una pomata veterinaria agli occhi del mouse per prevenire la secchezza e preparare il mouse per il trapianto come segue: </li><li> Posizionare il mouse sotto il microscopio da dissezione in una posizione reclinata laterale destro in modo che il lato rasata è rivolto verso l&#39;alto. Starting nel centro della zona chirurgica, dispensare in un movimento circolare utilizzando una pipetta di trasferimento monouso 70% etanolo, seguito da povidone-iodio (Betadine). Ripetere il trattamento di etanolo / betadine 3 volte prima di effettuare una incisione. </li><li> Con le forbici dissezione fanno un 1-2 cm un&#39;incisione fianco direttamente sopra il rene. </li><li> Utilizzando pinze medie afferrare tessuto connettivo adiacente al rene e sollevare delicatamente il rene in modo che si trova in cima alla muscolatura. Per mantenere il rene esposta e in posizione sopra la muscolatura, inserire un braccio di pinze medie sotto il rene, con particolare attenzione a non disturbare il ileo renale. </li><li> Al fine di prevenire l&#39;essiccamento del tessuto, irrigare il rene con sterile 1x PBS (pH 7.4) durante ogni passaggio finché manipolazione della capsula renale e rene è completo. </li><li> Utilizzando una pinza sottile pizzicare e sollevare la capsula vicino al bordo del rene più distale alle ghiandole surrenali per separarlo dal rene. </li><li> Utilizzare un calibro 18ago per fare una incisione abbastanza grande per inserire il pezzo preparato del timo donatore (Figura 2A). Assicurarsi di mantenere l&#39;incisione capsulare più piccolo possibile per impedire la dislocazione dell&#39;innesto nel tempo. </li><li> Pur mantenendo la capsula tirato via dal rene, utilizzare una seconda coppia di pinza sottile per inserire l&#39;innesto sotto la capsula e spingere il timo il più avanti dall&#39;incisione capsulare possibile (Figura 2B). </li><li> Rimuovere le pinze da sotto il rene, e restituire delicatamente il rene al suo posto attraverso l&#39;incisione. </li><li> Chiudere la muscolatura da sutura alla parete peritoneale e l&#39;applicazione di betadine una volta chiusa. Dopo sutura, applicare la clip ferita per chiudere il derma e applicare betadine alla zona circostante. </li><li> Ritorna il mouse in una gabbia che si è riscaldato con una lampada di calore. </li><li> Monitorare ogni mouse post-operatorio fino a quando non riprende piena consapevolezza e la mobilità e non posizionare i topi that non hanno recuperato dopo anestesia in una gabbia con altri animali. </li><li> Trattare topi con post-operatorie farmaci di gestione del dolore, se necessario. Fornire topi con analgesici post-operatorie, come paracetamolo in acqua potabile ad una concentrazione di 1,6 mg / ml. </li><li> Ripetere i passaggi 2,3-2,9 per ogni mouse destinatario. </li><li> Assicurarsi che il ritorno topi alla normale attività entro post-operatorio 1 ora. Monitorare peso post-operatorio, capacità motorie, nonché l&#39;acqua e mangime attività di ciascuna mouse per determinare complicazioni derivanti della procedura di trapianto. NOTA: la perdita di peso post-operatorio, rispetto al peso pre-operatoria, nonché la mobilità alterato o mancata mangiare o bere può indicare complicazioni. </li><li> Monitorare la ricostituzione delle cellule T del sangue periferico da sanguinamento topi con coda nick seguita dalla separazione dei linfociti che utilizzano mezzi di separazione cellulare Lympholyte secondo le specifiche del costruttore. Realizzare characteriza cellule Tzione mediante colorazione con anticorpi coniugati linfociti fluorescenza specifici per i marcatori di cellule T CD3, CD4, CD8, e così come un discriminatore morti vivono come un estere attivato 8 succinimidile fluorescente. Analisi come mostrato in Figura 3 può essere realizzato mediante gating su singlets, cellule vive e cellule positive CD3. </li></ol>

<ol>
	<li>Kappler, J. W., Roehm, N., Marrack, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=T+cell+tolerance+by+clonal+elimination+in+the+thymus.">T cell tolerance by clonal elimination in the thymus.</a> Cell. 49 (2), 273-280 (1987).</li><li>Takahama, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Journey+through+the+thymus:+stromal+guides+for+T-cell+development+and+selection.">Journey through the thymus: stromal guides for T-cell development and selection.</a> Nat. Rev. Immunol. 6, 127-135 (2006).</li><li>Klein, L., Kyewski, B., Allen, P. M., Hogquist, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Positive+and+negative+selection+of+the+T+cell+repertoire:+what+thymocytes+see+(and+don&#8217;t+see).">Positive and negative selection of the T cell repertoire: what thymocytes see (and don&#8217;t see).</a> Nat. Rev. Immunol. 14 (6), 377-391 (2014).</li><li>Schwartz, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acquisition+of+immunologic+self-tolerance.">Acquisition of immunologic self-tolerance.</a> Cell. 57 (7), 1073-1081 (1989).</li><li>Kishimoto, H., Sprent, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+defect+in+central+tolerance+in+NOD+mice.">A defect in central tolerance in NOD mice.</a> Nat. Immunol. 2 (11), 1025-1031 (2001).</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=Investigating+central+tolerance+with+reaggregate+thymus+organ+cultures.">Investigating central tolerance with reaggregate thymus organ cultures.</a> Methods. Mol. Biol. 380, 185-196 (2007).</li><li>He, Q., 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=Thymic+development+of+autoreactive+T+cells+in+NOD+mice+is+regulated+in+an+age-dependent+manner.">Thymic development of autoreactive T cells in NOD mice is regulated in an age-dependent manner.</a> J. Immunol. 191 (12), 5858-5866 (2013).</li><li>Stewart, C. C., Stewart, 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=Chapter+6.+Immunophenotyping.">Chapter 6. Immunophenotyping.</a> Current Protocols in Cytometry. , (2001).</li><li>Rice, H. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thymic+transplantation+for+complete+DiGeorge+syndrome:+medical+and+surgical+considerations.">Thymic transplantation for complete DiGeorge syndrome: medical and surgical considerations.</a> J. Pediatr. Surg. 39 (11), 1607-1615 (2004).</li><li>Markert, M. L., 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=Transplantation+of+thymus+tissue+in+complete+DiGeorge+Syndrome.">Transplantation of thymus tissue in complete DiGeorge Syndrome.</a> N. Engl. J. Med. 341, 1180-1189 (1999).</li><li>Market, M. L., Devlin, B. H., McCarthy, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thymus+transplantation.">Thymus transplantation.</a> Clin. Immunol. 135 (2), 236-246 (2010).</li><li>Wells, A. D., Li, X., Strom, T. B., Turka, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+peripheral+T-cell+depletion+in+transplantation+tolerance.">The role of peripheral T-cell depletion in transplantation tolerance.</a> Philos. Trans. R. Soc. Lond. B. Biol. Sci. 356 (1409), 617-623 (2001).</li><li>Albuquerque, A. 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=Human+FOXN1-Deficiency+is+associated+with+ab+double-negative+and+FoxP3++T-cell+expansions+that+are+distinctly+modulated+upon+thymic+transplantation.">Human FOXN1-Deficiency is associated with ab double-negative and FoxP3+ T-cell expansions that are distinctly modulated upon thymic transplantation.</a> PLoS One. 7 (5), e37042 (2012).</li><li>Chinn, I. K., Milner, J. D., Scheinberg, P., Douek, D. C., Markert, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thymus+transplantation+restores+the+repertoires+of+forkhead+box+protein+3+(FoxP3)++and+FoxP3-+T+cells+in+complete+DiGeorge+anomaly.">Thymus transplantation restores the repertoires of forkhead box protein 3 (FoxP3)+ and FoxP3- T cells in complete DiGeorge anomaly.</a> Clin Exp Immunol. 173 (1), 140-149 (2013).</li><li>Savino, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+thymus+is+a+common+target+organ+in+infectious+diseases.">The thymus is a common target organ in infectious diseases.</a> PLoS Pathog. 2 (6), e62 (2006).</li></ol>

The authors do not have any competing financial interests to disclose.

Events regulating thymic selection are poorly understood. Recent studies have demonstrated ontogenic changes in the efficiency of selection. Coupling this approach with different transgenic thymus donor and recipient mice will further facilitate studies to identify the events and parameters that regulate thymic selection. Notably, thymic transplantation is used for the treatment and management of T cell and thymic disorders seen for instance in athymic infants lacking functional T cells and in patients with DiGeorge synd...

Il timo è un organo in cui gli eventi critici nello sviluppo delle cellule T si verificano 1. Timociti residente sul riarrangiamento del recettore delle cellule T (TCR) α e β geni, subiscono una serie di interazioni con lymphostromal e cellule presentanti l&#39;antigene (APC) nelle regioni corticali e midollari del timo 2. Thymic selezione positiva è mediata da cellule epiteliali corticali timici (TEC) per produrre timociti che riconoscono peptidi antigenici nell&#39;ambito dell&#39;ospite classe complesso maggiore di istocompatibilità (MHC) I e II molecole 2-3. Successivamente timica selezione negativa comporta spurgo dei timociti autoreattivi, guidato da un&#39;interazione con TEC midollare o cellule dendritiche (DC) che presentano peptidi derivati ​​da auto-proteine ​​legate da MHC di classe I e II molecole 3. Il risultato finale di questi processi è la creazione di un pool di cellule mature CD4 + e CD8 + T in grado di rispondere ad un ampio spettrodi antigeni estranei mentre esibendo reattività minima auto-proteine ​​4. L&#39;efficienza di eventi di selezione timici è influenzata da una serie di fattori, tra cui la maturazione timica, frequenza midollare e TEC corticale, composizione sottoinsieme di timico DC, e la fonte di precursori timici 3. In particolare, la selezione del timo aberranti può provocare autoimmuni 5 o immunodeficienza patologie che derivano da alterazioni selezione negativa o positiva, rispettivamente. Gli eventi molecolari che regolano la selezione del timo, tuttavia, sono poco conosciuti. In vitro approcci come reaggregate colture d&#39;organo del timo (RTOC) 6, hanno dimostrato di essere utile per analizzare gli eventi di base associate con la selezione del timo, ma non riescono a riassumere pienamente le dinamiche del corso negli eventi vivo. Di conseguenza, questo approccio basato trapianto-timico è stato stabilito a migliori eventi di selezione thymocyte studio in vivo 7 </sup&gt;. Questo protocollo descrive trapianto thymi da topi donatori neonati e per adulti in immunodeficienti topi riceventi SCID. Questa tecnica permette lo studio dei meccanismi che regolano la selezione timica positiva e negativa, nonché uscita timica di vari sottogruppi di cellule T durante l&#39;ontogenesi. Recentemente, questo approccio è stato utilizzato per dimostrare che l&#39;efficienza della selezione timica è limitato subito dopo la nascita in topi con conseguente aumento sviluppo di cellule T autoreattive e una ridotta repertorio cellule T specifiche per antigeni estranei 7.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Ethanol&#160;</td>
			<td>Decon Laboratories</td>
			<td>2705HC</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>GIBCO</td>
			<td>14190-144</td>
			<td>pH 7.2</td>
		</tr>
		<tr>
			<td>Betadine Solution</td>
			<td>Purdue Products</td>
			<td>67618-150-17</td>
			<td></td>
		</tr>
		<tr>
			<td>18 gauge needle</td>
			<td>BD</td>
			<td>305195</td>
			<td></td>
		</tr>
		<tr>
			<td>Sutures (1.0 metric)</td>
			<td>Ethicon</td>
			<td>J493G</td>
			<td>18&#34; (45cm)</td>
		</tr>
		<tr>
			<td>AUTOCLIP Wound Clips (9mm)</td>
			<td>Clay Adams&#174; Brand</td>
			<td>427631</td>
			<td></td>
		</tr>
		<tr>
			<td>Transfer pipette</td>
			<td>Fisher Scientific</td>
			<td>13-711-20</td>
			<td>Sterile, disposable</td>
		</tr>
		<tr>
			<td>Mouse anti-CD3 Ab</td>
			<td>eBioscience</td>
			<td>11-0031-85</td>
			<td>Clone: 1452C11</td>
		</tr>
		<tr>
			<td>Mouse anti-CD4 Ab</td>
			<td>eBioscience</td>
			<td>48-0042-82</td>
			<td>Clone: RM4-5</td>
		</tr>
		<tr>
			<td>Mouse anti-CD8 Ab</td>
			<td>eBioscience</td>
			<td>25-0081-82</td>
			<td>Clone: 53-6.7</td>
		</tr>
		<tr>
			<td>Lancet</td>
			<td>Medipoint</td>
			<td>Goldenrod 4mm</td>
			<td></td>
		</tr>
		<tr>
			<td>Pacific Orange Succinimidyl Ester, Triethylammonium Salt</td>
			<td>Invitrogen</td>
			<td>P30253</td>
			<td></td>
		</tr>
		<tr>
			<td>96-well round botton polypropylene plates</td>
			<td>Corning</td>
			<td>3365</td>
			<td></td>
		</tr>
		<tr>
			<td>1.2mL polypropylene cluster tubes</td>
			<td>Corning</td>
			<td>4401</td>
			<td></td>
		</tr>
		<tr>
			<td>5mL polypropylene round-bottom tubes</td>
			<td>BD</td>
			<td>352002</td>
			<td></td>
		</tr>
		<tr>
			<td>40uM Nylon Cell Strainer</td>
			<td>Falcon</td>
			<td>352340</td>
			<td></td>
		</tr>
		<tr>
			<td>16% Paraformaldehyde Solution, EM Grade</td>
			<td>Electron Microscopy Services</td>
			<td>15710</td>
			<td>Hazardous</td>
		</tr>
		<tr>
			<td>Puralube Optical Ointment</td>
			<td>Fisher Scientific</td>
			<td>NC0138063</td>
			<td></td>
		</tr>
		<tr>
			<td>Lympholyte</td>
			<td>Cedarlane</td>
			<td>CL5030</td>
			<td></td>
		</tr>
		<tr>
			<td>60 mm cell culture dish</td>
			<td>Corning</td>
			<td>430196</td>
			<td>60mm x 15mm, Sterile</td>
		</tr>
	</tbody>
</table>

isolation and transplantation of different aged murine thymic grafts.

I meccanismi che regolano l&#39;efficacia della selezione timica restano mal definiti. Il metodo qui presentato permette in vivo analisi dello sviluppo e selezione di cellule T specifiche per sé e antigeni estranei. L&#39;approccio prevede l&#39;impianto di innesti timici derivate da diversi topi anziani in riceventi SCID immunodeficienti. Nel corso di un periodo relativamente breve di tempo i destinatari sono completamente ricostituiti con cellule T derivate dal trapianto del timo impiantata. Solo timociti semina timo al momento della selezione subiscono isolamento e svilupparsi in cellule T mature. Come tali, i cambiamenti nella natura e la specificità delle cellule T trapiantate in funzione di eventi timici dipendenti dall&#39;età possono essere valutate. Anche se è richiesta competenza tecnica per il trapianto timica successo, questo metodo fornisce una strategia unica di studiare in vivo una vasta gamma di patologie che sono causa o il risultato di aberrant funzione e / o homeostas timicoè.

Il successo di questa procedura dipende trauma chirurgico minimo nonché il posizionamento accurato del graft sotto la capsula renale. L&#39;innesto timica deve essere tagliato per assicurare dimensioni appropriate sezioni timici per il successivo trapianto, come mostrato in Figura 1. Seguendo lo schema di figura 1, thymi da topi neonati o adulti può essere usato per il trapianto subcapsular successo con risultati costanti e riproducibili attecchimento delle cellule T. Come accennato, ...

Watch this Scientific Journal Video about Isolation and Transplantation of Different Aged Murine Thymic Grafts. at JoVE.com

Isolation and Transplantation of Different Aged Murine Thymic Grafts.

This report provides a detailed description of transplanting murine thymi from different aged donor mice under the kidney capsule of immunodeficient mouse recipients. The goal of this approach is to model T cell development and thymic selection events in vivo.

Isolamento e Trapianto di diversi invecchiato murini del timo innesti.

The mechanisms that regulate the efficacy of thymic selection remain ill-defined. The method presented here allows in vivo analyses of the development and ...

isolation-and-transplantation-of-different-aged-murine-thymic-grafts

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Immunology and Infection

13.7K Views.  University of North Carolina at Chapel Hill. This report provides a detailed description of transplanting murine thymi from different aged donor mice under the kidney capsule of immunodeficient mouse recipients. The goal of this approach is to model T cell development and thymic selection events in vivo. 

Video: Isolation and Transplantation of Different Aged Murine Thymic Grafts.

Murine Model of CD40-activation of B cells

Research on B cells has shown that CD40 activation improves their antigen presentation capacity. When stimulated with interleukin-4 and CD40 ligand (CD40L), human B cells can be expanded without difficulties from small amounts of peripheral blood within 14 days to very large amounts of highly-pure CD40-B cells (&gt;109 cells per patient) from healthy donors as well as cancer patients1-4. CD40-B cells express important lymph node homing molecules and can attract T cells in vitro5. Furthermore they efficiently take up, process and present antigens to T cells6,7. CD40-B cells were shown to not only prime na&iacute;ve, but also expand memory T cells8,9. Therefore CD40-activated B cells (CD40-B cells) have been studied as an alternative source of immuno-stimulatory antigen-presenting cells (APC) for cell-based immunotherapy1,5,10. In order to further study whether CD40-B cells induce effective T cell responses in vivo and to study the underlying mechanism we established a cell culture system for the generation of murine CD40-activated B cells. Using splenocytes or purified B cells from C57BL/6 mice for CD40-activation, optimal conditions were identified as follows: Starting from splenocytes of C57BL/6 mice (haplotype H-2b) lymphocytes are purified by density gradient centrifugation and co-cultured with HeLa cells expressing recombinant murine CD40 ligand (tmuCD40L HeLa)11. Cells are recultured every 3-4 days and key components such as CD40L, interleukin-4, -Mercaptoethanol and cyclosporin A are replenished. In this protocol we demonstrate how to obtain fully activated murine CD40-B cells (mCD40B) with similar APC-phenotype to human CD40-B cells (Fig 1a,b). CD40-stimulation leads to a rapid outgrowth and expansion of highly pure (&gt;90%) CD19+ B cells within 14 days of cell culture (Fig 1c,d). To avoid contamination with non-transfected cells, expression of the murine CD40 ligand on the transfectants has to be controlled regularly (Fig 2). Murine CD40-activated B cells can be used to study B-cell activation and differentiation as well as to investigate their potential to function as APC in vitro and in vivo. Moreover, they represent a promising tool for establishing therapeutic or preventive vaccination against tumors and will help to answer questions regarding safety and immunogenicity of this approach12.

In this video, we demonstrate the procedure of CD40-activation and expansion of murine B cells from splenocytes of C57BL/6 mice, which can be used as a model antigen-presenting cell (APC) to study induction of immunity.

Modello murino di CD40-attivazione delle cellule B

Research on B cells has shown that CD40 activation improves their antigen presentation capacity. When stimulated with interleukin-4 and CD40 ligand ...

Ricerca

Immunologia e infezioni

RNA Isolation of Pseudomonas aeruginosa Colonizing the Murine Gastrointestinal Tract

Pseudomonas aeruginosa (PA) infections result in significant morbidity and mortality in hosts with compromised immune systems, such as patients with leukemia, severe burn wounds, or organ transplants1. In patients at high-risk for developing PA bloodstream infections, the gastrointestinal (GI) tract is the main reservoir for colonization2, but the mechanisms by which PA transitions from an asymptomatic colonizing microbe to an invasive, and often deadly, pathogen are unclear. Previously, we performed in vivo transcription profiling experiments by recovering PA mRNA from bacterial cells residing in the cecums of colonized mice 3 in order to identify changes in bacterial gene expression during alterations to the host&#x2019;s immune status.
As with any transcription profiling experiment, the rate-limiting step is in the isolation of sufficient amounts of high quality mRNA. Given the abundance of enzymes, debris, food residues, and particulate matter in the GI tract, the challenge of RNA isolation is daunting. Here, we present a method for reliable and reproducible isolation of bacterial RNA recovered from the murine GI tract. This method utilizes a well-established murine model of PA GI colonization and neutropenia-induced dissemination4. Once GI colonization with PA is confirmed, mice are euthanized and cecal contents are recovered and flash frozen. RNA is then extracted using a combination of mechanical disruption, boiling, phenol/chloroform extractions, DNase treatment, and affinity chromatography. Quantity and purity are confirmed by spectrophotometry (Nanodrop Technologies) and bioanalyzer (Agilent Technologies) (Fig 1). This method of GI microbial RNA isolation can easily be adapted to other bacteria and fungi as well.

RNA Isolation of Pseudomonas aeruginosa Colonizing the Murine Gastrointestinal Tract

A reliable method for the RNA isolation of Pseudomonas aeruginosa recovered from murine cecums is described. The RNA recovered is of sufficient quantity and quality for subsequent qPCR, transcription profiling, and RNA Seq experiments. This technique can be adapted for RNA isolation of other intestinal microbes.

Isolamento del RNA Pseudomonas aeruginosa Colonizzare la Murine tratto gastrointestinale

Pseudomonas aeruginosa (PA) infections result in significant morbidity and mortality in hosts with compromised immune systems, such as patients with ...

Examination of Thymic Positive and Negative Selection by Flow Cytometry

A healthy immune system requires that T cells respond to foreign antigens while remaining tolerant to self-antigens. Random rearrangement of the T cell receptor (TCR) &alpha; and &beta; loci generates a T cell repertoire with vast diversity in antigen specificity, both to self and foreign. Selection of the repertoire during development in the thymus is critical for generating safe and useful T cells. Defects in thymic selection contribute to the development of autoimmune and immunodeficiency disorders1-4. 
T cell progenitors enter the thymus as double negative (DN) thymocytes that do not express CD4 or CD8 co-receptors. Expression of the &alpha;&beta;TCR and both co-receptors occurs at the double positive (DP) stage. Interaction of the &alpha;&beta;TCR with self-peptide-MHC (pMHC) presented by thymic cells determines the fate of the DP thymocyte. High affinity interactions lead to negative selection and elimination of self-reactive thymocytes. Low affinity interactions result in positive selection and development of CD4 or CD8 single positive (SP) T cells capable of recognizing foreign antigens presented by self-MHC5.
Positive selection can be studied in mice with a polyclonal (wildtype) TCR repertoire by observing the generation of mature T cells. However, they are not ideal for the study of negative selection, which involves deletion of small antigen-specific populations. Many model systems have been used to study negative selection but vary in their ability to recapitulate physiological events6. For example, in vitro stimulation of thymocytes lacks the thymic environment that is intimately involved in selection, while administration of exogenous antigen can lead to non-specific deletion of thymocytes7-9. Currently, the best tools for studying in vivo negative selection are mice that express a transgenic TCR specific for endogenous self-antigen. However, many classical TCR transgenic models are characterized by premature expression of the transgenic TCR&alpha; chain at the DN stage, resulting in premature negative selection. Our lab has developed the HYcd4 model, in which the transgenic HY TCR&alpha; is conditionally expressed at the DP stage, allowing negative selection to occur during the DP to SP transition as occurs in wildtype mice10.
Here, we describe a flow cytometry-based protocol to examine thymic positive and negative selection in the HYcd4 mouse model. While negative selection in HYcd4 mice is highly physiological, these methods can also be applied to other TCR transgenic models. We will also present general strategies for analyzing positive selection in a polyclonal repertoire applicable to any genetically manipulated mice.

We present a flow cytometry-based method to examine T cell development in vivo using genetically manipulated mice on a wildtype or T cell receptor transgenic background.

Esame di Selezione timica positivi e negativi per Citometria a Flusso

A healthy immune system requires that T cells respond to foreign  antigens while remaining tolerant to self-antigens. Random rearrangement of the  T cell ...

Isolation, Processing and Analysis of Murine Gingival Cells

We have developed a technique to precisely isolate and process murine gingival tissue for flow cytometry and molecular studies. The gingiva is a unique and important tissue to study immune mechanisms because it is involved in host immune response against oral biofilm that might cause periodontal diseases. Furthermore, the close proximity of the gingiva to alveolar bone tissue enables also studying bone remodeling under inflammatory conditions. Our method yields large amount of immune cells that allows analysis of even rare cell populations such as Langerhans cells and T regulatory cells as we demonstrated previously 1. Employing mice to study local immune responses involved in alveolar bone loss during periodontal diseases is advantageous because of the availability of various immunological and experimental tools. Nevertheless, due to their small size and the relatively inconvenient access to the murine gingiva, many studies avoided examination of this critical tissue. The method described in this work could facilitate gingival analysis, which hopefully will increase our understating on the oral immune system and its role during periodontal diseases.

This study describes an efficient technique to isolate and process gingival tissues from the mouse oral cavity in order to produce a single-cell culture. The resulting cells can be further used for flow cytometry analysis and molecular studies.

Isolamento, elaborazione ed analisi dei murini gengivali

We have developed a technique to precisely isolate and process murine gingival tissue for flow cytometry and molecular studies. The gingiva is a unique ...

Isolation, Identification, and Purification of Murine Thymic Epithelial Cells

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple stages of T cell development: T cell commitment, positive selection and negative selection. However, the function of TECs in the thymus remains incompletely understood. In the article, we provide a method to isolate TEC subsets from fresh mouse thymus using a combination of mechanical disruption and enzymatic digestion. The method allows thymic stromal cells and thymocytes to be efficiently released from cell-cell and cell-extracellular matrix connections and to form a single-cell suspension. Using the isolated cells, multiparameter flow cytometry can be applied to identification and characterization of TECs and dendritic cells. Because TECs are a rare cell population in the thymus, we also describe an effective way to enrich and purify TECs by depleting thymocytes, the most abundant cell type in the thymus. Following the enrichment, cell sorting time can be decreased so that loss of cell viability can be minimized during purification of TECs. Purified cells are suitable for various downstream analyses like Real Time-PCR, Western blot and gene expression profiling. The protocol will promote research of TEC function and as well as the development of in vitro T cell reconstitution.

Here we describe an efficient method for isolation, identification, and purification of mouse thymic epithelial cells (TECs). The protocol can be utilized for studies of thymus function for normal T cell development, thymus dysfunction, and T cell reconstitution.

Isolamento, identificazione e purificazione di cellule murine timica epiteliali

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple ...

Isolation of Murine Lymph Node Stromal Cells

Secondary lymphoid organs including lymph nodes are composed of stromal cells that provide a structural environment for homeostasis, activation and differentiation of lymphocytes. Various stromal cell subsets have been identified by the expression of the adhesion molecule CD31 and glycoprotein podoplanin (gp38), T zone reticular cells or fibroblastic reticular cells, lymphatic endothelial cells, blood endothelial cells and FRC-like pericytes within the double negative cell population. For all populations different functions are described including, separation and lining of different compartments, attraction of and interaction with different cell types, filtration of the draining fluidics and contraction of the lymphatic vessels. In the last years, different groups have described an additional role of stromal cells in orchestrating and regulating cytotoxic T cell responses potentially dangerous for the host. 
Lymph nodes are complex structures with many different cell types and therefore require a appropriate procedure for isolation of the desired cell populations. Currently, protocols for the isolation of lymph node stromal cells rely on enzymatic digestion with varying incubation times; however, stromal cells and their surface molecules are sensitive to these enzymes, which results in loss of surface marker expression and cell death. Here a short enzymatic digestion protocol combined with automated mechanical disruption to obtain viable single cells suspension of lymph node stromal cells maintaining their surface molecule expression is proposed.

Isolation of lymph node stromal cells is a multistep procedure including enzymatic digestion and mechanical disaggregation to obtain fibroblastic reticular cells, lymphatic and blood endothelial cells. In the described procedure, a short digestion is combined with automated mechanical disaggregation to minimize surface marker degradation of viable lymph node stromal cells.

Isolamento di cellule murine Linfonodo stromali

Secondary lymphoid organs including lymph nodes are composed of stromal cells that provide a structural environment for homeostasis, activation and ...

Isolation and Intravenous Injection of Murine Bone Marrow Derived Monocytes

As a subtype of leukocytes and progenitors of macrophages, monocytes are involved in many important processes of organisms and are often the subject of various fields in biomedical science. The method described below is a simple and effective way to isolate murine monocytes from heterogeneous bone marrow.
Bone marrow from the femur and tibia of Balb/c mice is harvested by flushing with phosphate buffered saline (PBS). Cell suspension is supplemented with macrophage-colony stimulating factor (M-CSF) and cultured on ultra-low attachment surfaces to avoid adhesion-triggered differentiation of monocytes. The properties and differentiation of monocytes are characterized at various intervals. Fluorescence activated cell sorting (FACS), with markers like CD11b, CD115, and F4/80, is used for phenotyping. At the end of cultivation, the suspension consists of 45%&#177; 12% monocytes. By removing adhesive macrophages, the purity can be raised up to 86%&#177; 6%. After the isolation, monocytes can be utilized in various ways, and one of the most effective and common methods for in vivo delivery is intravenous tail vein injection. 
This technique of isolation and application is important for mouse model studies, especially in the fields of inflammation or immunology. Monocytes can also be used therapeutically in mouse disease models.

Here we present a protocol that generates large amounts of murine monocytes from heterogeneous bone marrow for translational applications. In comparison to others, this new method helps reduce the number of sacrificed animals and lowers costs by avoiding expensive methods such as high gradient magnetic cell separation (MACS).

Isolamento e iniezione endovenosa di Murine derivate dal midollo osseo monociti

As a subtype of leukocytes and progenitors of macrophages, monocytes are involved in many important processes of organisms and are often the subject of ...

Isolation and Flow Cytometric Characterization of Murine Small Intestinal Lymphocytes

The intestines &#8212; which contain the largest number of immune cells of any organ in the body &#8212; are constantly exposed to foreign antigens, both microbial and dietary. Given an increasing understanding that these luminal antigens help shape the immune response and that education of immune cells within the intestine is critical for a number of systemic diseases, there has been increased interest in characterizing the intestinal immune system. However, many published protocols are arduous and time-consuming. We present here a simplified protocol for the isolation of lymphocytes from the small-intestinal lamina propria, intraepithelial layer, and Peyer&#39;s patches that is rapid, reproducible, and does not require laborious Percoll gradients. Although the protocol focuses on the small intestine, it is also suitable for analysis of the colon. Moreover, we highlight some aspects that may need additional optimization depending on the specific scientific question. This approach results in the isolation of large numbers of viable lymphocytes that can subsequently be used for flow cytometric analysis or alternate means of characterization.

There is growing interest in the quantitative characterization of intestinal lymphocytes owing to increasing recognition that these cells play a critical role in a variety of intestinal and systemic diseases. In this protocol, we describe how to isolate single cell populations from different small-intestinal compartments for subsequent flow cytometric characterization.

Isolamento e caratterizzazione citometria a flusso di Murine Piccolo intestinale Linfociti

The intestines &#8212; which contain the largest number of immune cells of any organ in the body &#8212; are constantly exposed to foreign antigens, both ...

Preparation and Applications of Organotypic Thymic Slice Cultures

Thymic selection proceeds in a unique and highly organized thymic microenvironment resulting in the generation of a functional, self-tolerant T cell repertoire. In vitro models to study T lineage commitment and development have provided valuable insights into this process. However, these systems lack the complete three-dimensional thymic milieu necessary for T cell development and, therefore, are incomplete approximations of in vivo thymic selection. Some of the challenges related to modeling T cell development can be overcome by using in situ models that provide an intact thymic microenvironment that fully supports thymic selection of developing T cells. Thymic slice organotypic cultures complement existing in situ techniques. Thymic slices preserve the integrity of the thymic cortical and medullary regions and provide a platform to study development of overlaid thymocytes of a defined developmental stage or of endogenous T cells within a mature thymic microenvironment. Given the ability to generate ~20 slices per mouse, thymic slices present a unique advantage in terms of scalability for high throughput experiments. Further, the relative ease in generating thymic slices and potential to overlay different thymic subsets or other cell populations from diverse genetic backgrounds enhances the versatility of this method. Here we describe a protocol for the preparation of thymic slices, isolation and overlay of thymocytes, and dissociation of thymic slices for flow cytometric analysis. This system can also be adapted to study non-conventional T cell development as well as visualize thymocyte migration, thymocyte-stromal cell interactions, and TCR signals associated with thymic selection by two-photon microscopy.

We describe the preparation of thymic slices that, in combination with flow cytometry, can be used to model positive and negative selection of developing T cells. Thymic slices can also be adapted for the in situ analysis of thymocyte migration, localization, and signaling via immunofluorescence and two-photon microscopy.

Preparazione e applicazioni di colture organotipiche timica Slice

Thymic selection proceeds in a unique and highly organized thymic microenvironment resulting in the generation of a functional, self-tolerant T cell ...

Isolation and Activation of Murine Lymphocytes

B and T cells, with their extremely diverse antigen-receptor repertoires, have the ability to mount specific immune responses against almost any invading pathogen1,2. Understandably, such intricate abilities are controlled by a large number of molecules involved in various cellular processes to ensure timely and spatially regulated immune responses3. Here, we describe experimental procedures that allow rapid isolation of highly purified murine lymphocytes using magnetic cell sorting technology. The resulting purified lymphocytes can then be subjected to various in vitro or in vivo functional assays, such as the determination of lymphocyte signaling capacity upon stimulation by immunoblotting4 and the investigation of proliferative abilities by 3H-thymidine incorporation or carboxyfluorescein diacetate succinimidyl ester (CFSE) labeling5-7. In addition to comparing the functional capacities of control and genetically modified lymphocytes, we can also determine the T cell stimulatory capacity of antigen-presenting cells (APCs) in vivo, as shown in our representative results using transplanted CFSE-labeled OT-I T cells.

Lymphocytes are the major players in adaptive immune responses. Here, we present a lymphocyte purification protocol to determine the physiological functions of the desired molecules in lymphocyte activation in vitro and in vivo. The described experimental procedures are suitable for comparing functional capacities between control and genetically modified lymphocytes.

L&#39;isolamento e l&#39;attivazione di linfociti murini

B and T cells, with their extremely diverse antigen-receptor repertoires, have the ability to mount specific immune responses against almost any invading ...