Agradecemos a membros do Laboratório de Biologia phagosome para a leitura crítica do manuscrito. Este trabalho é apoiado por uma bolsa de Helmholtz Young Investigator (Iniciativa e os fundos de rede da Associação Helmholtz) e um Programa Prioritário SPP1580 Grant do Conselho de Pesquisa Alemão (Deutsche Forschungsgemeinschaft, DFG).

<ol>
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S., Jaumouille, V., Grinstein, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cell+biology+of+phagocytosis.">The cell biology of phagocytosis.</a> Annu. Rev. Pathol. 7, 61-98 (2012).</li><li>Vieira, O. V., Botelho, R. J., Grinstein, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phagosome+maturation:+aging+gracefully.">Phagosome maturation: aging gracefully.</a> Biochem. J. 366, 689-704 (2002).</li><li>Haas, 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+phagosome:+compartment+with+a+license+to+kill.">The phagosome: compartment with a license to kill.</a> Traffic. 8, 311-330 (2007).</li><li>Flannagan, R. S., Cosio, G., Grinstein, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antimicrobial+mechanisms+of+phagocytes+and+bacterial+evasion+strategies.">Antimicrobial mechanisms of phagocytes and bacterial evasion strategies.</a> Nat Rev Microbiol. 7, 355-366 (2009).</li><li>Luzio, J., Pryor, P., Bright, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lysosomes:+fusion+and+function.">Lysosomes: fusion and function.</a> Nat. Rev. Mol. Cell Biol. 8, 622-632 (2007).</li><li>Huotari, J., Helenius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endosome+maturation.">Endosome maturation.</a> EMBO J. 30, 3481-3500 (2011).</li><li>Luzio, J. P., 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=Lysosome-endosome+fusion+and+lysosome+biogenesis.">Lysosome-endosome fusion and lysosome biogenesis.</a> J. Cell. Sci. 113 (pt 9), 1515-1524 (2000).</li><li>Eissenberg, L., Goldman, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fusion+of+lysosomes+with+phagosomes+containing+Histoplasma+capsulatum:+use+of+fluoresceinated+dextran).">Fusion of lysosomes with phagosomes containing Histoplasma capsulatum: use of fluoresceinated dextran).</a> Adv. Exp. Med. Biol. 239, 53-61 (1988).</li><li>de Souza Carvalho, 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=Internalization,+phagolysosomal+biogenesis+and+killing+of+mycobacteria+in+enucleated+epithelial+cells.">Internalization, phagolysosomal biogenesis and killing of mycobacteria in enucleated epithelial cells.</a> Cell. Microbiol. 13, 1234-1249 (2011).</li><li>Wang, Y. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+and+sequential+delivery+of+fluorescent+lysosomal+probes+into+phagosomes+in+mouse+peritoneal+macrophages.">Differential and sequential delivery of fluorescent lysosomal probes into phagosomes in mouse peritoneal macrophages.</a> J. Cell Biol. 104, 1749-1754 (1987).</li><li>Harrison, R. E., Bucci, C., Vieira, O. V., Schroer, T. A., Grinstein, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phagosomes+Fuse+with+Late+Endosomes+and/or+Lysosomes+by+Extension+of+Membrane+Protrusions+along+Microtubules:+Role+of+Rab7+and+RILP.">Phagosomes Fuse with Late Endosomes and/or Lysosomes by Extension of Membrane Protrusions along Microtubules: Role of Rab7 and RILP.</a> Mol. Cell. Biol. 23, 6494-6506 (2003).</li><li>Huynh, K. K., 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=LAMP+proteins+are+required+for+fusion+of+lysosomes+with+phagosomes.">LAMP proteins are required for fusion of lysosomes with phagosomes.</a> EMBO J. 26, 313-324 (2007).</li><li>Kasmapour, B., Gronow, A., Bleck, C., Hong, W., Gutierrez, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size-dependent+mechanism+of+cargo+sorting+during+lysosome-phagosome+fusion+is+controlled+by+Rab34.">Size-dependent mechanism of cargo sorting during lysosome-phagosome fusion is controlled by Rab34.</a> Proc. Natl. Acad. Sci. U.S.A. 109, 20485-20490 (2012).</li><li>Snijder, 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=Population+context+determines+cell-to-cell+variability+in+endocytosis+and+virus+infection.">Population context determines cell-to-cell variability in endocytosis and virus infection.</a> Nature. 461, 520-523 (2009).</li><li>Knight, M., Roberts, S., Lee, D., Bader, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+cell+imaging+using+confocal+microscopy+induces+intracellular+calcium+transients+and+cell+death.">Live cell imaging using confocal microscopy induces intracellular calcium transients and cell death.</a> Am. J. Physiol. Cell Physiol. 284, 9 (2003).</li><li>Hemmi, 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=A+Toll-like+receptor+recognizes+bacterial+DNA.">A Toll-like receptor recognizes bacterial DNA.</a> Nature. 408, 740-745 (2000).</li><li>Underhill, D., Ozinsky, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toll-like+receptors:+key+mediators+of+microbe+detection.">Toll-like receptors: key mediators of microbe detection.</a> Curr. Opin. Immunol. 14, 103-110 (2002).</li><li>Bohdanowicz, M., Cos&#237;o, G., Backer, J., Grinstein, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Class+I+and+class+III+phosphoinositide+3-kinases+are+required+for+actin+polymerization+that+propels+phagosomes.">Class I and class III phosphoinositide 3-kinases are required for actin polymerization that propels phagosomes.</a> J. Cell Biol. 191, 999-1012 (2010).</li><li>Hoffmann, 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=Initial+receptor-ligand+interactions+modulate+gene+expression+and+phagosomal+properties+during+both+early+and+late+stages+of+phagocytosis.">Initial receptor-ligand interactions modulate gene expression and phagosomal properties during both early and late stages of phagocytosis.</a> Eur. J. Cell Biol. 89, 693-704 (2010).</li><li>Yates, R., Hermetter, A., Russell, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+kinetics+of+phagosome+maturation+as+a+function+of+phagosome/lysosome+fusion+and+acquisition+of+hydrolytic+activity.">The kinetics of phagosome maturation as a function of phagosome/lysosome fusion and acquisition of hydrolytic activity.</a> Traffic. 6, 413-420 (2005).</li><li>Savina, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NOX2+controls+phagosomal+pH+to+regulate+antigen+processing+during+crosspresentation+by+dendritic+cells.">NOX2 controls phagosomal pH to regulate antigen processing during crosspresentation by dendritic cells.</a> Cell. 126, 205-218 (2006).</li><li>Yates, R., Hermetter, A., Russell, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recording+phagosome+maturation+through+the+real-time,+spectrofluorometric+measurement+of+hydrolytic+activities.">Recording phagosome maturation through the real-time, spectrofluorometric measurement of hydrolytic activities.</a> Methods Mol. Biol. 531, 157-171 (2009).</li><li>Russell, D., Vanderven, B., Glennie, S., Mwandumba, H., Heyderman, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+macrophage+marches+on+its+phagosome:+dynamic+assays+of+phagosome+function.">The macrophage marches on its phagosome: dynamic assays of phagosome function.</a> Nat. Rev. Immunol. 9, 594-600 (2009).</li><li>Hoffmann, 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=Autonomous+phagosomal+degradation+and+antigen+presentation+in+dendritic+cells.">Autonomous phagosomal degradation and antigen presentation in dendritic cells.</a> Proc. Natl. Acad. Sci. U.S.A. 109, 14556-14561 (2012).</li><li>Tan, S., Sukumar, N., Abramovitch, R., Parish, T., Russell, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mycobacterium+tuberculosis+Responds+to+Chloride+and+pH+as+Synergistic+Cues+to+the+Immune+Status+of+its+Host+Cell.">Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell.</a> PLoS Pathog. 9, (2013).</li><li>Aziz, M., Yang, W. -. L., Wang, P., Coliganet, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+phagocytic+engulfment+of+apoptotic+cells+by+macrophages+using+pHrodo+succinimidyl+ester.">Measurement of phagocytic engulfment of apoptotic cells by macrophages using pHrodo succinimidyl ester.</a> Current protocols in immunology. 14, (2013).</li><li>Rogers, L., Foster, 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+dynamic+phagosomal+proteome+and+the+contribution+of+the+endoplasmic+reticulum.">The dynamic phagosomal proteome and the contribution of the endoplasmic reticulum.</a> Proc. Natl. Acad. Sci. U.S.A. 104, 18520-18525 (2007).</li><li>Russell, D. G., Vanderven, B. C., Glennie, S., Mwandumba, H., Heyderman, R. 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Na seção seguinte, vamos discutir as etapas críticas do método apresentado e as suas limitações. Além disso, iremos ligar alguns dos problemas comuns com as suas soluções, introdução de modificações possíveis e considerar as vantagens de nosso método, bem como métodos complementares adequadas para esta abordagem. A preparação dos grânulos, incluindo o acoplamento de IgG para a superfície do grânulo, é essencial e deve ser evitado o uso de preparações unfresh. Em adiç...

Fagócitos profissionais, incluindo macrófagos, desempenham um importante no sistema imune. Para além de ser a primeira linha de defesa do sistema imune inato, eles também desempenham um papel crítico na activação da imunidade adaptativa através da sua sinalização e apresentação de antigénio papel 1-3. Enquanto a função de fagócitos profissionais é multifacetada, maturação do fagossoma é crítica a espinha dorsal da função de processamento de antigénio e bactericida dos fagócitos profissionais 4,5. Após a imersão e absorção de um alvo fagocíticas, tais como bactérias receptor mediada, o fagossomo nascente passa por uma seqüência complexa e bem orquestrada de interação e intercâmbio com compartimentos da rede endocítica e várias outras organelas celulares 6. A natureza dos compostos trocados com essas entidades celulares, bem como a regulação e do calendário de eventos de fusão determina a phagosomal meio luminal e as phagoscomposição omal membrana e, portanto, 7, o destino do phagosome amadurecimento 8. A relevância fisiológica da maturação do fagossoma é exemplificado pelas diversas estratégias empregadas por vários patógenos intracelulares para escapar, prender ou subverter maturação phagosome 9. A maioria destas estratégias directamente ou indirectamente impedir a fase final e crítica do processo de maturação do fagossoma: a fusão do fagossoma com tardias compartimentos endossomal / lisossomal, que lhes confere, com a maior parte das enzimas hidrolíticas e factores anti-bacteriana de um fagossoma madura 7 , 8,10. A análise desta etapa final e crítico, portanto, pode fornecer-nos com fortes indicadores sobre o estado de maturação das phagosomes e se o estado fisiológico natural está a ser positiva ou negativamente afetados nas configurações experimentais particulares que estão sendo utilizados. O compartimento final endossomal / lisossomals são geralmente considerados como os compartimentos de terminais da via endocítica, definidos e distintos dos compartimentos endocíticas início com a presença de vários, Palco, moléculas marcadoras específicas. Por exemplo enzimas hidrolíticas ou componentes de membrana tais como proteínas de membrana Lysosomal associados (lâmpadas), entre outros 11. O terminal endocítico compartimentos-doravante referidos simplesmente como lisossomos-também servir como o principal local para as fases finais da digestão no final do fagocitária / endocítico caminho 12. Deste modo, as sondas não digeríveis podem ser carregados através de endocitose e macropinocitose do meio extracelular e transportado através da via endocítica para os lisossomas, onde se acumula 13,14 depois de seguir um ciclo de absorção definido e perseguição. Sondas fluoróforos para a microscopia de fluorescência, tais como o dextrano não digerível polímero orgânico são geralmente usados ​​como endocyticprobes 15-17. <p class = &quot;jove_content&quot;&gt; Neste método, que descrevem a utilização de micro-esferas revestidas com IgG como carga fagocítica investigar maturação do fagossoma, analisando a entrega do conteúdo luminal lisossomal para fagossomas. Ao usar uma sonda dextrano fluoróforo conjugado como um marcador facilmente detectável dos lisossomos na medula óssea ao vivo macrófagos derivados (BMM) e imagens de vídeo time-lapse com um microscópio de varredura a laser confocal, acompanhamos o processo dinâmico de entrega da carga em phagosomes com alta resolução temporal. Em seguida, descrevem como os dados de imagens de lapso de tempo coletados podem ser avaliados usando o código-fonte aberto e software de análise de imagens disponíveis gratuitamente, Fiji (ou ImageJ), e analisados ​​estatisticamente usando o Microsoft Excel e apresentados utilizando software GraphPad Prism 14,18. Após a descrição do nosso método, experiências análogas podem ser projetados usando as configurações e os fatores modificados para investigar sua influência na maturação phagosome; praticamente qualquer otseu tipo de células fagocíticas primárias ou de linha de células aderentes, perda genética de experimentos de função, incluindo gene knock-out e knock-down, mutantes ou expressão de proteínas de fusão, fagocíticas-alvos, compostos de revestimento microbead, sondas endosomal / lisossomais e fatores de citocinas, inibidores químicos, ou siRNA entre outros, são todos variáveis ​​que podem ser aplicadas à abordagem básica deste método. Definimos o objetivo e os requisitos básicos deste método da seguinte forma: <ul type="disc"><li> Objetivo do método: para permitir a observação directa, quantitativa e qualitativa e análise de maturação do fagossoma com alta resolução temporal em células fagocíticas vivo. </li><li> Carga fagocítica: Uma micropartícula apropriadamente revestidos ou alvo biológico. Aqui usamos IgG-revestido 3 mM micropartículas de poliestireno esféricas que são rapidamente internalizados através do receptor de Fc-γ fagocitose mediada. Alternativamente, qualquer microrganismo ou microfone revestidoroparticle para o qual um receptor de fagocítica está presente nas células pode ser utilizado. </li><li> As células fagocíticas: células fagocíticas aderentes que expressam os receptores apropriados fagocíticas. Aqui usamos primários BMMs rato que abundantemente expressam os receptores Fc-γ. Alternativamente, as células dendríticas (DC), monócitos ou células epiteliais fagocíticas ou seus mutantes ou variantes genéticas knock-out podem ser usados. </li><li> Carga Lysosomal: Uma sonda fluorescente etiquetado lisossômico. Aqui, conjugado com vermelho do Texas 70000 kDa dextrano (Dex70kD) é usado como carga o lúmen dos lisossomos. Alternativamente, qualquer marcador detectável por fluorescência de um compartimento celular ou organelo, ou uma sonda adequada para propriedades phagosomal como acidez ou de degradação da capacidade, pode ser utilizado para estudar a progressão da maturação do fagossoma. </li><li> Fatores que influenciam: Por exemplo, moléculas de sinalização, compostos químicos, gene knock-down, ou expressão transitória de proteínas mutantes poderia. Aqui, nós Forgum uso de tal fator para uma questão de simplicidade, mas para um exemplo recente com a expressão da proteína mutante e knock-down que influenciam fatores por favor ver Kasmapour et al. 18 Qualquer fator que pode afetar a fagocitose ou as circunstâncias e mobilidade dos phagosomes e / ou os compartimentos que interagem com phagosomes maturação poderia potencialmente ser usada. </li></ul>

<table border="0" cellpadding="0" cellspacing="0" width="610">
	<tbody>
		<tr>
			<td>Dulbecco&#39;s Modified Eagles Medium (D-MEM)</td>
			<td>PAA, Austria</td>
			<td>E15-009</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagles Medium without phenol red (D-MEM)</td>
			<td>PAA, Austria</td>
			<td>E15-047</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>PAA, Austria</td>
			<td>A15-151</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Glutamine</td>
			<td>PAA, Austria</td>
			<td>M11-004</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>PAA, Austria</td>
			<td>H15-002</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin</td>
			<td>PAA, Austria</td>
			<td>P11-010</td>
			<td></td>
		</tr>
		<tr>
			<td>WillCo-dish&#174; Glass bottom dish (35 mm &#8709;, #1.5)</td>
			<td>WillCo Wells, Netherlands</td>
			<td>GWSt-3522</td>
			<td></td>
		</tr>
		<tr>
			<td>CELLviewTM glass bottom dish, 35 mm</td>
			<td>Greiner Bio one, Germany</td>
			<td>627871</td>
			<td>Alternative: Available as segmented</td>
		</tr>
		<tr>
			<td>Carboxylated latex microspheres</td>
			<td>Polysciences, USA</td>
			<td>#09850</td>
			<td>Available in different diameters, we used 3 &#956;m</td>
		</tr>
		<tr>
			<td>Polystyrene microparticles</td>
			<td>Kisker Biotech, Germany</td>
			<td>PPs-3.0COOH</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton-X 100</td>
			<td>ROTH, Germany</td>
			<td>305.1.3</td>
			<td></td>
		</tr>
		<tr>
			<td>mouse whole IgG</td>
			<td>Rockland, USA</td>
			<td>010-0102</td>
			<td></td>
		</tr>
		<tr>
			<td>EDAC crosslinker</td>
			<td>Sigma-Aldrich, USA</td>
			<td>E6383-1g</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mM Tris</td>
			<td>Sigma-Aldrich,USA</td>
			<td>T1503</td>
			<td></td>
		</tr>
		<tr>
			<td>1-ml syringe Omnifix -F</td>
			<td>B.Braun, Germany</td>
			<td>9161406V</td>
			<td></td>
		</tr>
		<tr>
			<td>26&#160;G needle (0.45*25 mm)</td>
			<td>B.Baun, Germany</td>
			<td>4657683</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>PAA, Austria</td>
			<td>E15-039</td>
			<td></td>
		</tr>
		<tr>
			<td>Horse Serum</td>
			<td>Gibco, USA</td>
			<td>16050-122</td>
			<td></td>
		</tr>
		<tr>
			<td>MES hydrate</td>
			<td>Sigma-Aldrich, USA</td>
			<td>M2933</td>
			<td></td>
		</tr>
		<tr>
			<td>0.2 &#956;M syringe mounted filter</td>
			<td>Sartorius, Germany</td>
			<td>83.1826.001</td>
			<td></td>
		</tr>
	</tbody>
</table>

study of phagolysosome biogenesis in live macrophages

As células fagocíticas desempenhar um papel importante no sistema imune inato de remoção e eliminação de microrganismos invasores nas suas phagosomes. Maturação do fagossoma é o processo complexo e bem regulado durante o qual um phagosome nascente passa por uma transformação drástica por meio de interações bem orquestrados com diversas organelas celulares e compartimentos no citoplasma. Este processo, que é essencial para a função fisiológica das células fagocíticas, dotando phagosomes com suas propriedades líticas e bactericidas, culmina na fusão de fagossomos com lisossomos e biogênese de phagolysosomes que é considerada a última e crucial fase de maturação para phagosomes. Neste relatório, nós descrevemos um método baseado imagens de células vivas para a análise qualitativa e quantitativa do processo dinâmico de lisossoma para phagosome entrega de conteúdo, o que é uma característica da fagolisossomo biogênese. Esta abordagem utiliza microesferas IgG revestidas como um modelo para phagocytose e moléculas de dextrano fluoróforos como uma sonda de carga lisossômico luminal, a fim de acompanhar a entrega dinâmica de conteúdo lysosmal aos phagosomes em tempo real em macrófagos ao vivo usando imagens time-lapse e microscopia confocal a laser. Aqui vamos descrever em detalhe o plano de fundo, as etapas de preparação e configuração passo-a-passo experimental para permitir a implantação fácil e preciso desse método em outros laboratórios. Nosso método descrito é simples, robusta, e mais importante, pode ser facilmente adaptado para estudar as interações phagosomal e maturação em diferentes sistemas e em várias configurações experimentais, tais como uso de vários tipos de células fagocíticas, experiências de perda de função, as diferentes sondas e partículas fagocíticas.

A preparação correcta das células e as pérolas de imagiologia é crítica. Figura 1 mostra o contorno da semeadura, a sonda de carregamento e as etapas iniciais de imagem neste método, com base no nosso protocolo optimizado para BMMs. É, portanto, essencial que os parâmetros de protocolo ser testada e optimizada, dependendo do tipo de células e as sondas que são para ser usados. Após a adição dos grânulos revestidos com IgG às células pré-carregadas, é impor...

Watch this Scientific Journal Video about Study of Phagolysosome Biogenesis in Live Macrophages at JoVE.com

Study of Phagolysosome Biogenesis in Live Macrophages

Estudo da fagolisossomo Biogenesis em macrófagos ao vivo

Phagocytic cells play a major role in the innate immune system by removing and eliminating invading microorganisms in their phagosomes. Phagosome ...

study-of-phagolysosome-biogenesis-in-live-macrophages

Research

JoVE Journal

Immunology and Infection

14.3K visualizações.  Helmholtz Centre for Infection Research. Estudo da fagolisossomo Biogenesis em macrófagos ao vivo

Vídeo: Study of Phagolysosome Biogenesis in Live Macrophages

Use of an Optical Trap for Study of Host-Pathogen Interactions for Dynamic Live Cell Imaging

Dynamic live cell imaging allows direct visualization of real-time interactions between cells of the immune system1, 2; however, the lack of spatial and temporal control between the phagocytic cell and microbe has rendered focused observations into the initial interactions of host response to pathogens difficult. Historically, intercellular contact events such as phagocytosis3 have been imaged by mixing two cell types, and then continuously scanning the field-of-view to find serendipitous intercellular contacts at the appropriate stage of interaction. The stochastic nature of these events renders this process tedious, and it is difficult to observe early or fleeting events in cell-cell contact by this approach. This method requires finding cell pairs that are on the verge of contact, and observing them until they consummate their contact, or do not. To address these limitations, we use optical trapping as a non-invasive, non-destructive, but fast and effective method to position cells in culture.
Optical traps, or optical tweezers, are increasingly utilized in biological research to capture and physically manipulate cells and other micron-sized particles in three dimensions4. Radiation pressure was first observed and applied to optical tweezer systems in 19705, 6, and was first used to control biological specimens in 19877. Since then, optical tweezers have matured into a technology to probe a variety of biological phenomena8-13.
We describe a method14 that advances live cell imaging by integrating an optical trap with spinning disk confocal microscopy with temperature and humidity control to provide exquisite spatial and temporal control of pathogenic organisms in a physiological environment to facilitate interactions with host cells, as determined by the operator. Live, pathogenic organisms like Candida albicans and Aspergillus fumigatus, which can cause potentially lethal, invasive infections in immunocompromised individuals15, 16 (e.g. AIDS, chemotherapy, and organ transplantation patients), were optically trapped using non-destructive laser intensities and moved adjacent to macrophages, which can phagocytose the pathogen. High resolution, transmitted light and fluorescence-based movies established the ability to observe early events of phagocytosis in living cells. To demonstrate the broad applicability in immunology, primary T-cells were also trapped and manipulated to form synapses with anti-CD3 coated microspheres in vivo, and time-lapse imaging of synapse formation was also obtained. By providing a method to exert fine spatial control of live pathogens with respect to immune cells, cellular interactions can be captured by fluorescence microscopy with minimal perturbation to cells and can yield powerful insight into early responses of innate and adaptive immunity.

A method is described to individually select, manipulate, and image live pathogens using an optical trap coupled to a spinning disk microscope. The optical trap provides spatial and temporal control of organisms and places them adjacent to host cells. Fluorescence microscopy captures dynamic intercellular interactions with minimal perturbation to cells.

Uso de uma armadilha óptica de Estudos de Interações Hospedeiro-Patógeno para imagens de células dinâmica ao vivo

Dynamic live cell imaging allows direct visualization of real-time interactions between cells of the immune system1, 2; however, the lack of spatial and ...

Imunologia e Infecção

Depletion and Reconstitution of Macrophages in Mice

Macrophages are critical players in the innate immune response to infectious challenge or injury, initiating the innate immune response and directing the acquired immune response. Macrophage dysfunction can lead to an inability to mount an appropriate immune response and as such, has been implicated in many disease processes, including inflammatory bowel diseases. Macrophages display polarized phenotypes that are broadly divided into two categories. Classically activated macrophages, activated by stimulation with IFN&gamma; or LPS, play an essential role in response to bacterial challenge whereas alternatively activated macrophages, activated by IL-4 or IL-13, participate in debris scavenging and tissue remodeling and have been implicated in the resolution phase of inflammation. During an inflammatory response in vivo, macrophages are found amid a complex mixture of infiltrating immune cells and may participate by exacerbating or resolving inflammation. To define the role of macrophages in situ in a whole animal model, it is necessary to examine the effect of depleting macrophages from the complex environment. To ask questions about the role of macrophage phenotype in situ, phenotypically defined polarized macrophages can be derived ex vivo, from bone marrow aspirates and added back to mice, with or without prior depletion of macrophages. In the protocol presented here clodronate-containing liposomes, versus PBS injected controls, were used to deplete colonic macrophages during dextran sodium sulfate (DSS)-induced colitis in mice. In addition, polarized macrophages were derived ex vivo and transferred to mice by intravenous injection. A caveat to this approach is that clodronate-containing liposomes deplete all professional phagocytes, including both dendritic cells and macrophages so to ensure the effect observed by depletion is macrophage-specific, reconstitution of phenotype by adoptive transfer of macrophages is necessary. Systemic macrophage depletion in mice can also be achieved by backcrossing mice onto a CD11b-DTR background, which is an excellent complementary approach. The advantage of clodronate-containing liposome-mediated depletion is that it does not require the time and expense involved in backcrossing mice and it can be used in mice regardless of the background of the mice (C57BL/6, BALB/c, or mixed background).

Macrophages play a central role in homeostasis and pathology in many tissues. The protocol presented here describes methods for depleting macrophages in vivo, deriving polarized macrophages from bone marrow aspirates, and adoptively transferring macrophages into mice. These techniques allow determination of the role that polarized macrophages play in health and disease.

Depleção e reconstituição de macrófagos em Ratos

Macrophages are critical players in the innate  immune response to infectious challenge or injury, initiating the innate immune  response and directing ...

Establishment of an In vitro System to Study Intracellular Behavior of Candida glabrata in Human THP-1 Macrophages

A cell culture model system, if a close mimic of host environmental conditions, can serve as an inexpensive, reproducible and easily manipulatable alternative to animal model systems for the study of a specific step of microbial pathogen infection. A human monocytic cell line THP-1 which, upon phorbol ester treatment, is differentiated into macrophages, has previously been used to study virulence strategies of many intracellular pathogens including Mycobacterium tuberculosis. Here, we discuss a protocol to enact an in vitro cell culture model system using THP-1 macrophages to delineate the interaction of an opportunistic human yeast pathogen Candida glabrata with host phagocytic cells. This model system is simple, fast, amenable to high-throughput mutant screens, and requires no sophisticated equipment. A typical THP-1 macrophage infection experiment takes approximately 24 hr with an additional 24-48 hr to allow recovered intracellular yeast to grow on rich medium for colony forming unit-based viability analysis. Like other in vitro model systems, a possible limitation of this approach is difficulty in extrapolating the results obtained to a highly complex immune cell circuitry existing in the human host. However, despite this, the current protocol is very useful to elucidate the strategies that a fungal pathogen may employ to evade/counteract antimicrobial response and survive, adapt, and proliferate in the nutrient-poor environment of host immune cells.

Establishment of an In vitro System to Study Intracellular Behavior of Candida glabrata in Human THP-1 Macrophages

The current article outlines a protocol to establish an in vitro cell culture model system to study the interaction of a facultative intracellular human fungal pathogen Candida glabrata with human macrophages which will be a useful tool to advance our knowledge of fungal virulence mechanisms.

Estabelecimento de um<em&gt; In vitro</em&gt; Sistema para estudar o comportamento intracelular de<em&gt; Candida glabrata</em&gt; Em humanos THP-1 macrófagos

A cell culture model system, if a close mimic of host environmental conditions, can serve as an inexpensive, reproducible and easily manipulatable ...

Use of Shigella flexneri to Study Autophagy-Cytoskeleton Interactions

Shigella flexneri is an intracellular pathogen that can escape from phagosomes to reach the cytosol, and polymerize the host actin cytoskeleton to promote its motility and dissemination. New work has shown that proteins involved in actin-based motility are also linked to autophagy, an intracellular degradation process crucial for cell autonomous immunity. Strikingly, host cells may prevent actin-based motility of S. flexneri by compartmentalizing bacteria inside &#8216;septin cages&#8217; and targeting them to autophagy. These observations indicate that a more complete understanding of septins, a family of filamentous GTP-binding proteins, will provide new insights into the process of autophagy. This report describes protocols to monitor autophagy-cytoskeleton interactions caused by S. flexneri in vitro using tissue culture cells and in vivo using zebrafish larvae. These protocols enable investigation of intracellular mechanisms that control bacterial dissemination at the molecular, cellular, and whole organism level.

Use of Shigella flexneri to Study Autophagy-Cytoskeleton Interactions

To counteract pathogen dissemination, host cells reorganize their cytoskeleton to compartmentalize bacteria and induce autophagy. Using Shigella infection of tissue culture cells, host and pathogen determinants underlying this process are identified and characterized. Using zebrafish models of Shigella infection, the role of discovered molecules and mechanisms are investigated in vivo.

Utilização de<em&gt; Shigella flexneri</em&gt; Para estudar interações Autophagy-Cytoskeleton

Shigella flexneri is an intracellular pathogen that can escape from phagosomes to reach the cytosol, and polymerize the host actin cytoskeleton to promote ...

Proteomic Profiling of Macrophages by 2D Electrophoresis

The goal of the two-dimensional (2D) electrophoresis protocol described here is to show how to analyse the phenotype of human cultured macrophages. The key role of macrophages has been shown in various pathological disorders such as inflammatory, immunological, and infectious diseases. In this protocol, we use primary cultures of human monocyte-derived macrophages that can be differentiated into the M1 (pro-inflammatory) or the M2 (anti-inflammatory) phenotype. This in vitro model is reliable for studying the biological activities of M1 and M2 macrophages and also for a proteomic approach. Proteomic techniques are useful for comparing the phenotype and behaviour of M1 and M2 macrophages during host pathogenicity. 2D gel electrophoresis is a powerful proteomic technique for mapping large numbers of proteins or polypeptides simultaneously. We describe the protocol of 2D electrophoresis using fluorescent dyes, named 2D Differential Gel Electrophoresis (DIGE). The M1 and M2 macrophages proteins are labelled with cyanine dyes before separation by isoelectric focusing, according to their isoelectric point in the first dimension, and their molecular mass, in the second dimension. Separated protein or polypeptidic spots are then used to detect differences in protein or polypeptide expression levels. The proteomic approaches described here allows the investigation of the macrophage protein changes associated with various disorders like host pathogenicity or microbial toxins.

Macrophages are the key cells involved in host pathogenicity. Macrophages display phenotypic and functional diversity that can be analysed and detected by proteomic analysis. This article describes how to perform 2D electrophoresis of primary cultures of human macrophages differentiated into M1 or M2 phenotype.

Proteômica Profiling de macrófagos por eletroforese 2D

The goal of the two-dimensional (2D) electrophoresis protocol described here is to show how to analyse the phenotype of human cultured macrophages. The ...

Quantification of Cytosolic vs. Vacuolar Salmonella in Primary Macrophages by Differential Permeabilization

Intracellular bacterial pathogens can replicate in the cytosol or in specialized pathogen-containing vacuoles (PCVs). To reach the cytosol, bacteria like Shigella flexneri and Francisella novicida need to induce the rupture of the phagosome. In contrast, Salmonella typhimurium replicates in a vacuolar compartment, known as Salmonella-containing vacuole (SCV). However certain mutants of Salmonella fail to maintain SCV integrity and are thus released into the cytosol. The percentage of cytosolic vs. vacuolar bacteria on the level of single bacteria can be measured by differential permeabilization, also known as phagosome-protection assay. The approach makes use of the property of detergent digitonin to selectively bind cholesterol. Since the plasma membrane contains more cholesterol than other cellular membranes, digitonin can be used to selectively permeabilize the plasma membrane while leaving intracellular membranes intact. In brief, following infection with the pathogen expressing a fluorescent marker protein (e.g. mCherry among others), the plasma membrane of host cells is permeabilized with a short incubation in digitonin containing buffer. Cells are then washed and incubated with a primary antibody (coupled to a fluorophore of choice) directed against the bacterium of choice (e.g. anti-Salmonella-FITC) and washed again. If unmarked bacteria are used, an additional step can be done, in which all membranes are permeabilized and all bacteria stained with a corresponding antibody. Following the staining, the percentage of vacuolar and cytosolic bacteria can be quantified by FACS or microscopy by counting single or double-positive events. Here we provide experimental details for use of this technique with the bacterium Salmonella typhimurium. The advantage of this assay is that, in contrast to other assay, it provides a quantification on the level of single bacteria, and if analyzed by microscopy provides the exact number of cytosolic and vacuolar bacteria in a given cell.

Quantification of Cytosolic vs. Vacuolar Salmonella in Primary Macrophages by Differential Permeabilization

We describe the quantification of cytosolic and vacuolar Salmonella typhimurium in bone-marrow derived macrophages using differential digitonin permeabilization.

Quantificação de citosólico vs vacuolar<em&gt; Salmonella</em&gt; Em macrófagos primários por Permeabilização Diferencial

Intracellular bacterial pathogens can replicate in the cytosol or in specialized pathogen-containing vacuoles (PCVs). To reach the cytosol, bacteria like ...

Phagosome Migration and Velocity Measured in Live Primary Human Macrophages Infected with HIV-1

Macrophages are phagocytic cells that play a major role at the crossroads between innate and specific immunity. They can be infected by the human immunodeficiency virus (HIV)-1 and because of their resistance to its cytopathic effects they can be considered to be persistent viral reservoirs. In addition, HIV-infected macrophages exhibit defective functions that contribute to the development of opportunistic diseases.
The exact mechanism by which HIV-1 impairs the phagocytic response of macrophages was unknown. We had previously shown that the uptake of various particulate material by macrophages was inhibited when they were infected with HIV-1. This inhibition was only partial and phagosomes did form within HIV-infected macrophages. Therefore, we focused on analyzing the fate of these phagosomes. Phagosome maturation is accompanied by migration of these compartments towards the cell center, where they fuse with lysosomes, generating phagolysosomes, responsible for degradation of the ingested material. We used IgG-opsonized Sheep Red Blood Cells as a target for phagocytosis. To measure the speed of centripetal movement of phagosomes in individual HIV-infected macrophages, we used a combination of bright field and fluorescence confocal microscopy. We established a method to calculate the distance of phagosomes towards the nucleus, and then to calculate the velocity of the phagosomes. HIV-infected cells were identified thanks to a GFP-expressing virus, but the method is applicable to non-infected cells or any type of infection or treatment.

We describe a method to measure the velocity of phagosomes moving towards the cell center in living cells infected with or without the human immunodeficiency virus (HIV) type 1, using spinning disk confocal fluorescence microscopy to identify fluorescent infected cells and bright field microscopy to detect phagosomes.

Migração fagossomo e velocidade medida no Live primárias macrófagos humanos infectados com o HIV-1

Macrophages are phagocytic cells that play a major role at the crossroads between innate and specific immunity. They can be infected by the human ...

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. typhimurium bacteria are quickly detected and phagocytized by macrophages, and contained in vesicles known as phagosomes in order to be degraded. Isolation of S. typhimurium-containing phagosomes have been widely used to study how S. typhimurium infection alters the process of phagosome maturation to prevent bacterial degradation. Classically, the isolation of bacteria-containing phagosomes has been performed by sucrose gradient centrifugation. However, this process is time-consuming, and requires specialized equipment and a certain degree of dexterity. Described here is a simple and quick method for the isolation of S. typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin-streptavidin-conjugated magnetic beads. Phagosomes obtained by this method can be suspended in any buffer of choice, allowing the utilization of isolated phagosomes for a broad range of assays, such as protein, metabolite, and lipid analysis. In summary, this method for the isolation of S. typhimurium-containing phagosomes is specific, efficient, rapid, requires minimum equipment, and is more versatile than the classical method of isolation by sucrose gradient-ultracentrifugation.

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

We describe here a simple and quick method for the isolation of Salmonella typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin and streptavidin.

Isolamento de Salmonella typhimurium-contendo Phagosomes de macrófagos

Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. ...

Isolation and In Vitro Culture of Murine and Human Alveolar Macrophages

Alveolar macrophages are terminally differentiated, lung-resident macrophages of prenatal origin. Alveolar macrophages are unique in their long life and their important role in lung development and function, as well as their lung-localized responses to infection and inflammation. To date, no unified method for identification, isolation, and handling of alveolar macrophages from humans and mice exists. Such a method is needed for studies on these important innate immune cells in various experimental settings. The method described here, which can be easily adopted by any laboratory, is a simplified approach to harvesting alveolar macrophages from bronchoalveolar lavage fluid or from lung tissue and maintaining them in vitro. Because alveolar macrophages primarily occur as adherent cells in the alveoli, the focus of this method is on dislodging them prior to harvest and identification. The lung is a highly vascularized organ, and various cell types of myeloid and lymphoid origin inhabit, interact, and are influenced by the lung microenvironment. By using the set of surface markers described here, researchers can easily and unambiguously distinguish alveolar macrophages from other leukocytes, and purify them for downstream applications. The culture method developed herein supports both human and mouse alveolar macrophages for in vitro growth, and is compatible with cellular and molecular studies.

Isolation and In Vitro Culture of Murine and Human Alveolar Macrophages

This communication describes methodologies for isolation and culture of alveolar macrophages from humans and murine models for experimental purposes.

Isolamento e cultura In Vitro de macrófagos alveolares murino e humanos

Alveolar macrophages are terminally differentiated, lung-resident macrophages of prenatal origin. Alveolar macrophages are unique in their long life and ...

Flow Cytometric Measurement Of ROS Production In Macrophages In Response To Fc&#947;R Cross-linking

The oxidative or respiratory burst is used to describe the rapid consumption of oxygen and generation of reactive oxygen species (ROS) by phagocytes in response to various immune stimuli. ROS generated during immune activation exerts potent antimicrobial activity primarily through the ability of ROS to damage DNA and proteins, causing death of microorganisms. Being able to measure ROS production reproducibly and with ease is necessary in order to assess the contribution of various pathways and molecules to this mechanism of host defense. In this paper, we demonstrate the use of fluorescent probes and flow cytometry to detect ROS production. Although widely used, fluorescent measurement of ROS is notoriously problematic, especially with regards to measurement of ROS induced by specific and not mitogenic stimuli. We present a detailed methodology to detect ROS generated as a result of specific Fc&#947;R stimulation beginning with macrophage generation, priming, staining, Fc&#947;R cross-linking, and ending with flow cytometric analysis.

This study demonstrates the use of flow cytometry to detect reactive oxygen species (ROS) production resulting from activation of the Fc&#947;R. This method can be used to assess changes in the antimicrobial and redox signaling function of phagocytes in response to immune complexes, opsonized microorganisms, or direct Fc&#947;R cross-linking.

Fluxo Cytometric medição da produção de ROS em macrófagos em resposta a FcγR cross-linking

The oxidative or respiratory burst is used to describe the rapid consumption of oxygen and generation of reactive oxygen species (ROS) by phagocytes in ...