Este trabalho foi financiado pela Universidade de Wisconsin-Madison Herman I. Shapiro Distinguished Graduados (CMT), NIH prêmio AI072817 (AMP) e American Heart Association Award 0840059N (LJK).

1. Preparação de fibroblastos humanos prepúcio (HFF) revestido lamínulas <ol><li> Coloque uma lamela de vidro estéril redonda sobre o fundo dos poços de uma placa de cultura de 24 poços de tecido. </li><li> Para colher HFFS de um frasco de 150 centímetros confluentes 2, lavar o balão com duas 1X PBS e adicionar 2,5 ml de 0,025% de tripsina-EDTA. Incubar frasco a 37 ° C por 5-10 minutos. </li><li> Tocando o lado do frasco contra a palma da sua mão pode ajudar em destacar as células do frasco. Uma vez que as células têm liberado do frasco, adicionar 150 ml de HFF médio (Modified Dulbecco Eagle Medium [DMEM] com 10% de SFB, 2 mM L-glutamina, e 1% de penicilina-estreptomicina) e use a médio e lavar o balão e recolher as células. </li><li> Dispensar 1 ml de células por bem com as lamelas. </li><li> Permitem que as células a se tornar confluentes, a 37 ° C, 5% CO 2. </li></ol> 2. Preparando L929 meio condicionado (MC) para desenvolvimento BMC <ol><li> L929 é uma linha de células aneuplóides murino fibrosarcoma que secreta colônia de macrófagos fator estimulador após longos períodos de confluência. Esta secreção permite que a CM da L929 células a serem utilizados para desenvolver células da medula óssea do rato em macrófagos em cultura de células 1. </li><li> Uma vez L929 células são confluentes, deixe-incubar por mais 7-9 dias até que eles aparecem esférica e começar a decolagem do balão. Recolher o sobrenadante e pellet quaisquer células destacadas a 425 xg por 10 minutos. Este sobrenadante é o CM. </li><li> Um frasco de 150 centímetros de duas células L929 rende 30 ml de CM, que gera 150 ml de meio de BMC. BMC médio é composto por 10% FBS, CM 20%, 1% de penicilina-estreptomicina, e 1% L-glutamina em DMEM. </li></ol> 3. Isolamento de medula óssea e de cultura de células de BMCs <ol><li> Sacrificar um rato C57BL / 6 por asfixia CO 2 e de superfície esterilizar com álcool 70%. </li><li> Expor o peritônio, levantando a pele abdominal, perto da perna e corte com tesoura. Evitar a punção da cavidade peritoneal. Cortadas para a perna para expor a tíbia eo fêmur. Cortar o tecido muscular dos ossos da perna com uma tesoura. </li><li> Para remover o fêmur, uma vez cortada abaixo do joelho e uma vez perto do quadril. Coloque os ossos em uma placa de Petri contendo bacteriológica frio 1X PBS. Não use cultura de tecidos tratados placas de Petri para essas etapas porque o BMCs vai aderir de forma permanente. Use um bisturi para raspar o tecido muscular extra. Cortar o osso logo acima do joelho para expor a medula. </li><li> Repita os passos (b) e (c) para coletar a medula óssea do fêmur segundo. </li><li> Use uma seringa de 10cc cheio de frio 1X PBS e uma agulha calibre 25 para desalojar a medula óssea em um tubo de 50 ml. O osso deve aparecer medula branco puro, uma vez é removido. </li><li> Passe a mistura PBS / medula através de uma agulha de calibre 22 para quebrar qualquer agregados de medula óssea. </li><li> Girar a mistura a 425 xg por 10 minutos, e remover o sobrenadante. </li><li> Ressuspender o sedimento em 8 ml de meio de BMC. Adicionar 1 ml de suspensão de células e 9 ml de meio BMC a 8 pratos bacteriológica Petri. </li><li> Incubar a 37 ° C, 5% CO 2. </li><li> No dia 5, adicione 10 ml de meio BMC para cada prato. No 7 º dia, as células serão totalmente desenvolvidos. BMCs podem ser várias passagens por 1-2 semanas após a maturação. </li><li> Para dividir BMCs, remova o meio e adicionar 5 ml de frio 1X PBS a cada placa de Petri. Incubar a 4 ° C por 30 minutos, até que as células começam a levantar. Lavar a BMCs off a placa com uma pipeta estéril. </li><li> Piscina do BMCs em um tubo de 50 ml e pellet a 425 xg por 10 minutos. </li><li> Ressuspender o sedimento em 10 ml de médio BMC e contar com um hemocitômetro. Semente 2x105 BMCs por bem em uma placa de 24 poços com lamínulas de vidro circulares na parte inferior. Deixe o BMCs aderir noite antes de infectar com o T. gondii. BMCs excesso pode ser reseeded em placas de Petri para uso posterior. </li></ol> 4. Infectar as células com T. gondii <ol><li> Infectar 25 cm 2 frasco de HFFS confluente com 2x10 6 T. gondii e crescer até que as células começam a lise (cerca de 2-3 dias). </li><li> Use um raspador para remover células da monocamada de células infectadas anfitrião do frasco de cultura de tecidos em seguida, solte os parasitas de células do hospedeiro, passando a monocamada desalojado através de uma agulha calibre 27. </li><li> Use um hemocitômetro para determinar o número de parasitas no meio. </li><li> Infectar 10 5 por parasitas bem com lamela de HFF monocamadas do Protocolo 1, ou BMCs do Protocolo 3. Deixe os parasitas invadem durante 3 horas a 37 ° C, 5% CO 2. </li></ol> 5. Iniciar T. gondii desenvolvimento bradyzoite por estresses ambientais <ol><li> Bradyzoite desenvolvimento em HFFS com o aumento do pH médio e fome CO 2 <ol class="lalpha"><li> Prepare meio do desenvolvimento. Médio de desenvolvimento contém RPMEu, sem bicarbonato de 1640, 1% FBS, 1% de penicilina-estreptomicina e 42 mM HEPES. pH para 8,0 e filtro esterilizar. </li><li> Remover DMEM de HFFS infectados, lavar com PBS 1X, e adicionar 1 ml de meio de desenvolvimento. </li><li> Incubar por 3 dias a 37 ° C com o ar ambiente. </li></ol></li><li> Ativação de BMCs <ol class="lalpha"><li> Prepare médio para ativar BMCs. Médio de ativação é BMC meio suplementado com IFN-γ 100U/ml e 100 ng / ml LPS. Sonicate LPS em banho-maria por 2 minutos antes de usar para interromper agregados. </li><li> Remover BMC meio de poços e substituir com 1 ml de meio de ativação. </li><li> Incubar a 37 ° C, 5% de CO 2 para 3 dias. </li></ol></li></ol> 6. Detecção de imunofluorescência <ol><li> Enxágüe infectados poços três vezes com 1X PBS. </li><li> Fixar a monocamada com 200ul de formaldeído a 3% por 20 minutos. </li><li> Remover fixador e lavar os poços com PBS 1X. </li><li> Adicionar 200μl de 0,1 M de glicina para poços e deixe descansar por 5 minutos. </li><li> Remover glicina e enxaguar poços com PBS 1X. </li><li> Adicionar 250 mL de 3% BSA/0.2% tritonX-100 em 1X PBS para permeabilizar e bloquear a monocamada por 30 minutos. </li><li> Remoção da solução de bloqueio e lavar os poços com PBS 1X. </li><li> Adicionar 50 ul de uma diluição de 1:250 de rodamina Dolichos biflorus aglutinina em 3% BSA/0.2% Triton X-100 em 1X PBS. </li><li> Cobrir a placa e colocar na plataforma shaker à temperatura ambiente por uma hora </li><li> Lavar as lamelas 3 vezes com 0,2% Triton X-100 em 1X PBS por 5 minutos cada em um agitador de plataforma. </li><li> Lamínulas de montagem utilizando VectaShield meio de montagem contendo 4&#39;6-diamidino-2-phenylindole (DAPI). </li><li> T. manchada gondii pode ser visualizado através de um microscópio fluorescente com um filtro apropriado para rodamina com uma ampliação de 100x. </li></ol> 7. Resultados representativos A Figura 1 mostra coloração representante da DBA T. gondii em BMMs ativado e HFFS sob estresse pH. Ambos mostram coloração DBA torno parasita contendo vacúolos, indicando a presença de componentes de parede do cisto. A imagem mostra BMM ativado coloração DBA que é consistente com a superfície do vacúolo. A seção transversal do T. gondii no pH salientou HFFS mostra a parede do cisto, sem estruturas internas manchado. <img src="/files/ftp_upload/2091/2091fig1.jpg" alt="Figura 1" /> Figura 1. DBA coloração de T. salientou gondii. parasitas intracelulares sob condições de estresse, BMMs ativado ou pH salientou HFFS, foram coradas com conjugado DBA rodamina (vermelho). Contraste de interferência diferencial (DIC) mostra o esboço do cisto e da barra de escala preto é igual a 2 mM. Experiências com animais Experimentos em animais foram realizados de acordo com as diretrizes e regulamentos estabelecidos pela Universidade de Wisconsin Animal Care e do Comitê Use.

<ol>
	<li>Tomida, M., Yamamoto-Yamaguchi, Y., Hozumi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+of+a+factor+inducing+differentiation+of+mouse+myeloid+leukemic+M1+cells+from+conditioned+medium+of+mouse+fibroblast+L929+cells.">Purification of a factor inducing differentiation of mouse myeloid leukemic M1 cells from conditioned medium of mouse fibroblast L929 cells.</a> J Biol Chem. 259 (17), 10978-10980 (1984).</li><li>Matrajt, M., Donald, R. G., Singh, U., Roos, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+characterization+of+differentiation+mutants+in+the+protozoan+parasite+Toxoplasma+gondii.">Identification and characterization of differentiation mutants in the protozoan parasite Toxoplasma gondii.</a> Mol Microbiol. 44, 735-747 (2002).</li><li>Singh, U., Brewer, J. L., Boothroyd, 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=Genetic+analysis+of+tachyzoite+to+bradyzoite+differentiation+mutants+in+Toxoplasma+gondii+reveals+a+hierarchy+of+gene+induction.">Genetic analysis of tachyzoite to bradyzoite differentiation mutants in Toxoplasma gondii reveals a hierarchy of gene induction.</a> Mol Microbiol. 44, 721-733 (2002).</li><li>J, P., Knoll, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+Toxoplasma+gondii+development+mutants+identifies+a+potential+proteophosphogylcan+that+enhances+cyst+wall+formation.+Molecular+and+Biochemical+Parasitology.">Isolation of Toxoplasma gondii development mutants identifies a potential proteophosphogylcan that enhances cyst wall formation. Molecular and Biochemical Parasitology.</a> 169 (2), 120-123 (2010).</li><li>Bohne, W., Heesemann, J., Gross, U. <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+Bradyzoite-Specific+Toxoplasma+gondii+Antigens+in+Gamma+Interferon-Treated+Mouse+Macrophages.">Induction of Bradyzoite-Specific Toxoplasma gondii Antigens in Gamma Interferon-Treated Mouse Macrophages.</a> Infection and Immunity. 61 (3), 1141-1145 (1993).</li><li>Ibrahim, H. M., Bannai, H., Xuan, X., Nishikawa, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxoplasma+gondii+Cyclophilin+18-Mediated+Production+of+Nitric+Oxide+Induces+Bradyzoite+Conversion+in+a+CCR5-Dependent+Manner.">Toxoplasma gondii Cyclophilin 18-Mediated Production of Nitric Oxide Induces Bradyzoite Conversion in a CCR5-Dependent Manner.</a> Infection and Immunity. 77 (9), 3686-3695 (2009).</li><li>Lyons, R. E., McLeod, R., Roberts, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxoplasma+gondii+tachyzoite-bradyzoite+interconversion.">Toxoplasma gondii tachyzoite-bradyzoite interconversion.</a> Trends in Parasitology. 18 (5), 198-201 (2002).</li><li>Berghaus, L. J., Moore, J. N., Hurley, D. J., Vandenplas, M. L., Fortes, B. P., Wolfert, M. A., Boons, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Innate+immune+responses+of+primary+murine+macrophage-lineage+cells+and+RAW+264.7+cells+to+ligands+of+Toll-like+receptors+2,+3,+and+4.">Innate immune responses of primary murine macrophage-lineage cells and RAW 264.7 cells to ligands of Toll-like receptors 2, 3, and 4.</a> Comp Immunol Microbiol Infect Dis. , (2009).</li><li>Mordue, D. G., Scott-Weathers, C. F., Tobin, C. M., Knoll, L. 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+patatin-like+protein+protects+Toxoplasma+gondii+from+degradation+in+activated+macrophages.">A patatin-like protein protects Toxoplasma gondii from degradation in activated macrophages.</a> Mol Microbiol. 63 (2), 482-496 (2007).</li><li>Bohne, W., Heesemann, J., Gross, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduced+replication+of+Toxoplasma+gondii+is+necessary+for+induction+of+bradyzoite-specific+antigens:+a+possible+role+for+nitric+oxide+in+triggering+stage+conversion.">Reduced replication of Toxoplasma gondii is necessary for induction of bradyzoite-specific antigens: a possible role for nitric oxide in triggering stage conversion.</a> Infection and Immunity. 62 (5), 1761-1777 (1994).</li></ol>

Não há conflitos de interesse declarados.

Embora o mecanismo de desenvolvimento bradyzoite não é totalmente compreendido, molecular análises genéticas de T. gondii estágio de conversão em cultura de tecidos tem levado à descoberta de genes que estão envolvidos na formação de cistos bradyzoite 2,3,4. As análises também levaram à observação de que alguns marcadores bradyzoite são expressas em outras condições de estresse prolongado, incluindo o crescimento em macrófagos ativados 5,6. Os métodos acima descrevem co...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Bovine serum albumin</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>A7906</td>
<td>&nbsp;</td>
<tr>
<td>Dulbecco's Modified Eagle Medium (DMEM)</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>11960-051</td>
<td>&nbsp;</td>
<tr>
<td>Fetal Bovine Serum (FBS)</td>
<td>&nbsp;</td>
<td>Atlanta Biologicals</td>
<td>S11150</td>
<td>heat inactivate </td>
</tr>
<tr>
<td>Rhodamine Dolichos biflorus agglutinin</td>
<td>&nbsp;</td>
<td>Vector Laboratories</td>
<td>RL-1032</td>
<td>&nbsp;</td>
<tr>
<td>Formaldehyde (16%)</td>
<td>&nbsp;</td>
<td>Polysciences</td>
<td>18814</td>
<td>&nbsp;</td>
<tr>
<td>Glycine</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>BP381-5</td>
<td>&nbsp;</td>
<tr>
<td>HEPES</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>BP310-1</td>
<td>&nbsp;</td>
<tr>
<td>IFN&gamma;</td>
<td>&nbsp;</td>
<td>PeproTech</td>
<td>315-05</td>
<td>Store in single use aliquots</td>
</tr>
<tr>
<td>L-glutamine (200mM)</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>25030</td>
<td>&nbsp;</td>
<tr>
<td>Lipopolysaccharide (LPS)</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>L4391-1MG</td>
<td>Store in single use aliquots</td>
</tr>
<tr>
<td>Microscope Cover Glass</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>12-545-80 12CIR-1</td>
<td>&nbsp;</td>
<tr>
<td>Penicillin-Streptomycin</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>15140</td>
<td>&nbsp;</td>
<tr>
<td>RPMI medium 1640 powder (with L-glutamine, without bicarbonate)</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>31800-022</td>
<td>&nbsp;</td>
<tr>
<td>Triton-X-100</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>BP151-500</td>
<td>&nbsp;</td>
<tr>
<td>Trypsin-EDTA (0.25%)</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>25200</td>
<td>&nbsp;</td>
<tr>
<td>VectaShield mounting media with DAPI</td>
<td>&nbsp;</td>
<td>Vector Laboratories</td>
<td>H-1200</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

toxoplasma gondii cyst wall formation in activated bone marrow-derived macrophages and bradyzoite conditions

Toxoplasma gondii é um parasita intracelular obrigatório que pode invadir qualquer célula nucleada de animais de sangue quente. Durante a infecção, T. gondii dissemina como uma forma rápida replicação chamado tachyzoite. Taquizoítos converter em uma forma de crescimento lento encistados chamado bradyzoite por um processo de sinalização que não está bem caracterizada. Dentro de animais, cistos bradyzoite são encontradas no sistema nervoso central e tecido muscular e representam a fase crônica da infecção. Conversão para bradyzoites pode ser simulada em cultura de tecidos por inanição CO 2, utilizando meio com pH elevado, ou a adição de interferon gama (IFNγ). Bradyzoites são caracterizadas pela presença de uma parede do cisto, a que a lectina Dolichos biflorus aglutinina (DBA) liga. DBA fluorescente etiquetado é usado para visualizar a parede do cisto no parasitas cultivados em fibroblastos humanos prepúcio (HFFS) que tenham sido expostos a baixa emissão de CO 2 e pH médio alto. Da mesma forma, os parasitas que residem no óssea de camundongos derivadas da medula macrófagos (BMMs) exibir uma parede do cisto detectáveis ​​por DBA após o BMMs são ativados com IFNγ e lipopolissacarídeo (LPS). Este protocolo irá demonstrar como induzir a conversão de T. gondii para bradyzoites usando um meio de crescimento elevado pH, com baixa de CO 2 e ativação de BMMs. Células do hospedeiro serão cultivadas em lamínulas, infectados com taquizoítos e quer ativado com adição de IFNγ e LPS (BMMs) ou expostos a um meio de alto pH de crescimento (HFFS) por três dias. Após a conclusão de infecções, células hospedeiras será corrigido, permeabilizadas, e bloqueado. Paredes do cisto será visualizado utilizando rodamina DBA com microscopia de fluorescência.

Watch this Scientific Journal Video about Toxoplasma gondii Cyst Wall Formation in Activated Bone Marrow-derived Macrophages and Bradyzoite Conditions at JoVE.com

Toxoplasma gondii Cyst Wall Formation in Activated Bone Marrow-derived Macrophages and Bradyzoite Conditions

Toxoplasma gondii se converte em uma forma de cisto em resposta ao estresse ambiental, que pode ser imitada em modelos de cultura de tecidos. Este vídeo demonstra técnicas para examinar a formação de parede do cisto, ativando derivadas da medula óssea macrófagos ou alterar o pH de crescimento médio em células de fibroblastos.

Toxoplasma gondii Formação parede do cisto no Activated derivadas da medula óssea macrófagos e Condições Bradyzoite

Toxoplasma gondii is an obligate intracellular parasite that can invade any nucleated cell of warm-blooded animals. During infection, T. gondii ...

toxoplasma-gondii-cyst-wall-formation-activated-bone-marrow-derived

Research

JoVE Journal

Immunology and Infection

Toxoplasma gondii Cyst Wall Formation in Activated Bone Marrow-derived Macrophages and Bradyzoite Conditions

16.1K visualizações.  University of Wisconsin. Toxoplasma gondii se converte em uma forma de cisto em resposta ao estresse ambiental, que pode ser imitada em modelos de cultura de tecidos. Este vídeo demonstra técnicas para examinar a formação de parede do cisto, ativando derivadas da medula óssea macrófagos ou alterar o pH de crescimento médio em células de fibroblastos.

Vídeo: Toxoplasma gondii Cyst Wall Formation in Activated Bone Marrow-derived Macrophages and Bradyzoite Conditions

Obtaining Highly Purified Toxoplasma gondii Oocysts by a Discontinuous Cesium Chloride Gradient

Toxoplasma gondii is an obligate intracellular protozoan pathogen that commonly infects humans. It is a well characterized apicomplexan associated with causing food- and water-borne disease outbreaks. The definitive host is the feline species where sexual replication occurs resulting in the development of the highly infectious and environmentally resistant oocyst. Infection occurs via ingestion of tissue cysts from contaminated meat or oocysts from soil or water. Infection is typically asymptomatic in healthy individuals, but results in a life-long latent infection that can reactivate causing toxoplasmic encephalitis and death if the individual becomes immunocompromised. Meat contaminated with T. gondii cysts have been the primary source of infection in Europe and the United States, but recent changes in animal management and husbandry practices and improved food handling and processing procedures have significantly reduced the prevalence of T. gondii cysts in meat1, 2. Nonetheless, seroprevalence in humans remains relatively high suggesting that exposure from oocyst contaminated soil or water is likely. Indeed, waterborne outbreaks of toxoplasmosis have been reported worldwide supporting the theory exposure to the environmental oocyst form poses a significant health risk3-5. To date, research on understanding the prevalence of T. gondii oocysts in the water and environment are limited due to the lack of tools to detect oocysts in the environment 5, 6. This is primarily due to the lack of efficient purification protocols for obtaining large numbers of highly purified T gondii oocysts from infected cats for research purposes. This study describes the development of a modified CsCl method that easily purifies T. gondii oocysts from feces of infected cats that are suitable for molecular biological and tissue culture manipulation7.

Obtaining Highly Purified Toxoplasma gondii Oocysts by a Discontinuous Cesium Chloride Gradient

This study describes the development of a modified CsCl method that easily purifies T. gondii oocysts from feces of infected cats that are suitable for molecular biological and tissue culture manipulation

Obtenção altamente purificada Toxoplasma gondii Oocistos por um gradiente de cloreto de césio descontínuos

Toxoplasma gondii is an obligate intracellular protozoan pathogen that commonly infects humans. It is a well characterized apicomplexan associated with ...

Imunologia e Infecção

A Genetic Screen to Isolate Toxoplasma gondii Host-cell Egress Mutants

The widespread, obligate intracellular, protozoan parasite Toxoplasma gondii causes opportunistic disease in immuno-compromised patients and causes birth defects upon congenital infection. The lytic replication cycle is characterized by three stages: 1. active invasion of a nucleated host cell; 2. replication inside the host cell; 3. active egress from the host cell. The mechanism of egress is increasingly being appreciated as a unique, highly regulated process, which is still poorly understood at the molecular level. The signaling pathways underlying egress have been characterized through the use of pharmacological agents acting on different aspects of the pathways1-5. As such, several independent triggers of egress have been identified which all converge on the release of intracellular Ca2+, a signal that is also critical for host cell invasion6-8. This insight informed a candidate gene approach which led to the identification of plant like calcium dependent protein kinase (CDPK) involved in egress9. In addition, several recent breakthroughs in understanding egress have been made using (chemical) genetic approaches10-12. To combine the wealth of pharmacological information with the increasing genetic accessibility of Toxoplasma we recently established a screen permitting the enrichment for parasite mutants with a defect in host cell egress13. Although chemical mutagenesis using N-ethyl-N-nitrosourea (ENU) or ethyl methanesulfonate (EMS) has been used for decades in the study of Toxoplasma biology11,14,15, only recently has genetic mapping of mutations underlying the phenotypes become routine16-18. Furthermore, by generating temperature-sensitive mutants, essential processes can be dissected and the underlying genes directly identified. These mutants behave as wild-type under the permissive temperature (35 &deg;C), but fail to proliferate at the restrictive temperature (40 &deg;C) as a result of the mutation in question. Here we illustrate a new phenotypic screening method to isolate mutants with a temperature-sensitive egress phenotype13. The challenge for egress screens is to separate egressed from non-egressed parasites, which is complicated by fast re-invasion and general stickiness of the parasites to host cells. A previously established egress screen was based on a cumbersome series of biotinylation steps to separate intracellular from extracellular parasites11. This method also did not generate conditional mutants resulting in weak phenotypes. The method described here overcomes the strong attachment of egressing parasites by including a glycan competitor, dextran sulfate (DS), that prevents parasites from sticking to the host cell19. Moreover, extracellular parasites are specifically killed off by pyrrolidine dithiocarbamate (PDTC), which leaves intracellular parasites unharmed20. Therefore, with a new phenotypic screen to specifically isolate parasite mutants with defects in induced egress, the power of genetics can now be fully deployed to unravel the molecular mechanisms underlying host cell egress.

A Genetic Screen to Isolate Toxoplasma gondii Host-cell Egress Mutants

Forward genetics is a powerful method to unravel the molecular level of how Toxoplasma egresses from its host cell. Protocols are provided to chemically mutagenize parasites, enrich for mutants with defects in induced egress, and validate the phenotype of cloned mutants.

A tela de genética para isolar Toxoplasma gondii Host de células mutantes egresso

The widespread, obligate intracellular, protozoan parasite Toxoplasma gondii causes opportunistic disease in immuno-compromised patients and causes birth ...

Investigation of Macrophage Polarization Using Bone Marrow Derived Macrophages

The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic stem/progenitor cells from the bone marrow are directed into monocytic differentiation, followed by M1 or M2 stimulation. The activation status can be tracked by changes in cell surface antigens, gene expression and cell signaling pathways.

The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic stem/progenitor cells from the bone marrow are directed into monocytic differentiation, followed by M1 or M2 stimulation. The activation status can be tracked by changes in cell surface antigens, gene expression and cell signaling pathways.

Investigação de polarização de macrófagos Usando medula macrófagos derivados

The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic ...

Genetic Manipulation in &Delta;ku80 Strains for Functional Genomic Analysis of Toxoplasma gondii

Targeted genetic manipulation using homologous recombination is the method of choice for functional genomic analysis to obtain a detailed view of gene function and phenotype(s). The development of mutant strains with targeted gene deletions, targeted mutations, complemented gene function, and/or tagged genes provides powerful strategies to address gene function, particularly if these genetic manipulations can be efficiently targeted to the gene locus of interest using integration mediated by double cross over homologous recombination.
Due to very high rates of nonhomologous recombination, functional genomic analysis of Toxoplasma gondii has been previously limited by the absence of efficient methods for targeting gene deletions and gene replacements to specific genetic loci. Recently, we abolished the major pathway of nonhomologous recombination in type I and type II strains of T. gondii by deleting the gene encoding the KU80 protein1,2. The &Delta;ku80 strains behave normally during tachyzoite (acute) and bradyzoite (chronic) stages in vitro and in vivo and exhibit essentially a 100% frequency of homologous recombination. The &Delta;ku80 strains make functional genomic studies feasible on the single gene as well as on the genome scale1-4.
Here, we report methods for using type I and type II &Delta;ku80&Delta;hxgprt strains to advance gene targeting approaches in T. gondii. We outline efficient methods for generating gene deletions, gene replacements, and tagged genes by targeted insertion or deletion of the hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) selectable marker. The described gene targeting protocol can be used in a variety of ways in &Delta;ku80 strains to advance functional analysis of the parasite genome and to develop single strains that carry multiple targeted genetic manipulations. The application of this genetic method and subsequent phenotypic assays will reveal fundamental and unique aspects of the biology of T. gondii and related significant human pathogens that cause malaria (Plasmodium sp.) and cryptosporidiosis (Cryptosporidium).

Genetic Manipulation in &lt;em&gt;&amp;Delta;ku80&lt;/em&gt; Strains for Functional Genomic Analysis of &lt;em&gt;Toxoplasma gondii&lt;/em&gt;

Here we report a method for using type I and type II &Delta;ku80 strains of Toxoplasma gondii to efficiently generate targeted gene deletions and gene replacements for functional genomic analysis.

Manipulação genética em<em&gt; Δku80</em&gt; Cepas para Análise Genômica Funcional de<em&gt; Toxoplasma gondii</em

Targeted genetic manipulation using homologous recombination is the method of choice for functional genomic analysis to obtain a detailed view of gene ...

Bone Marrow-derived Macrophage Production

Macrophages are critical components of the innate and adaptive immune responses, and they are the first line of defense against foreign invaders because of their powerful microbicidal activities. Macrophages are widely distributed throughout the body and are present in the lymphoid organs, liver, lungs, gastrointestinal tract, central nervous system, bone, and skin. Because of their repartition, they participate in a wide range of physiological and pathological processes. Macrophages are highly versatile cells that are able to recognize microenvironmental alterations and to maintain tissue homeostasis. Numerous pathogens have evolved mechanisms to use macrophages as Trojan horses to survive, replicate in, and infect both humans and animals and to propagate throughout the body. The recent explosion of interest in evolutionary, genetic, and biochemical aspects of host-pathogen interactions has renewed scientific attention regarding macrophages. Here, we describe a procedure to isolate and cultivate macrophages from murine bone marrow that will provide large numbers of macrophages for studying host-pathogen interactions as well as other processes.

Macrophages have long been recognized as a critical component of the innate and adaptive immune responses. The recent explosion of knowledge pertaining to evolutionary, genetic, and biochemical aspects of the interaction between macrophages and microbes has renewed scientific attention to macrophages. This article describes a method to differentiate macrophages from mouse bone marrow.

Medula Óssea derivadas de macrófagos Produção

Macrophages are critical components of the innate and adaptive immune responses, and they are the first line of defense against foreign invaders because ...

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 injecção intravenosa de Murino de Medula Óssea Derivado monócitos

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

Forward Genetics Screens Using Macrophages to Identify Toxoplasma gondii Genes Important for Resistance to IFN-&#947;-Dependent Cell Autonomous Immunity

Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan pathogen. The parasite invades and replicates within virtually any warm blooded vertebrate cell type. During parasite invasion of a host cell, the parasite creates a parasitophorous vacuole (PV) that originates from the host cell membrane independent of phagocytosis within which the parasite replicates. While IFN-dependent-innate and cell mediated immunity is important for eventual control of infection, innate immune cells, including neutrophils, monocytes and dendritic cells, can also serve as vehicles for systemic dissemination of the parasite early in infection. An approach is described that utilizes the host innate immune response, in this case macrophages, in a forward genetic screen to identify parasite mutants with a fitness defect in infected macrophages following activation but normal invasion and replication in na&#239;ve macrophages. Thus, the screen isolates parasite mutants that have a specific defect in their ability to resist the effects of macrophage activation. The paper describes two broad phenotypes of mutant parasites following activation of infected macrophages: parasite stasis versus parasite degradation, often in amorphous vacuoles. The parasite mutants are then analyzed to identify the responsible parasite genes specifically important for resistance to induced mediators of cell autonomous immunity. The paper presents a general approach for the forward genetics screen that, in theory, can be modified to target parasite genes important for resistance to specific antimicrobial mediators. It also describes an approach to evaluate the specific macrophage antimicrobial mediators to which the parasite mutant is susceptible. Activation of infected macrophages can also promote parasite differentiation from the tachyzoite to bradyzoite stage that maintains chronic infection. Therefore, methodology is presented to evaluate the importance of the identified parasite gene to establishment of chronic infection.

Forward Genetics Screens Using Macrophages to Identify Toxoplasma gondii Genes Important for Resistance to IFN-&amp;#947;-Dependent Cell Autonomous Immunity

Forward genetics is a powerful approach to identify genes in intracellular pathogens important for resistance to cell autonomous immunity. The current approach uses innate immune cells, specifically macrophages, to identify novel Toxoplasma gondii genes important for immune evasion.

Atacante Genetics telas usando macrófagos para Identificar<em&gt; Toxoplasma gondii</em&gt; genes importantes celular para Resistance to-IFN-γ Dependente Immunity Autónoma

Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan pathogen. The parasite invades and replicates within ...

Metabolic Characterization of Polarized M1 and M2 Bone Marrow-derived Macrophages Using Real-time Extracellular Flux Analysis

Specific metabolic pathways are increasingly being recognized as critical hallmarks of macrophage subsets. While LPS-induced classically activated M1 or M(LPS) macrophages are pro-inflammatory, IL-4 induces alternative macrophage activation and these so-called M2 or M(IL-4) support resolution of inflammation and wound healing. Recent evidence shows the crucial role of metabolic reprogramming in the regulation of M1 and M2 macrophage polarization. 
In this manuscript, an extracellular flux analyzer is applied to assess the metabolic characteristics of naive, M1 and M2 polarized mouse bone marrow-derived macrophages. This instrument uses pH and oxygen sensors to measure the extracellular acidification rate (ECAR) and oxygen consumption rate (OCR), which can be related to glycolytic and mitochondrial oxidative metabolism. As such, both glycolysis and mitochondrial oxidative metabolism can be measured in real-time in one single assay.
Using this technique, we demonstrate here that inflammatory M1 macrophages display enhanced glycolytic metabolism and reduced mitochondrial activity. Conversely, anti-inflammatory M2 macrophages show high mitochondrial oxidative phosphorylation (OXPHOS) and are characterized by an enhanced spare respiratory capacity (SRC). 
The presented functional assay serves as a framework to investigate how particular cytokines, pharmacological compounds, gene knock outs or other interventions affect the macrophage&#8217;s metabolic phenotype and inflammatory status.

Metabolic reprogramming is a characteristic and prerequisite for M1 and M2 macrophage polarization. This manuscript describes an assay for the measurement of fundamental parameters of glycolysis and mitochondrial function in mouse bone marrow-derived macrophages. This tool can be applied to investigate how particular factors affect the macrophage&#8217;s metabolism and phenotype.

Caracterização metabólica de Polarizada M1 e M2 macrófagos da medula óssea derivadas usando análises em tempo real do fluxo extracelular

Specific metabolic pathways are increasingly being recognized as critical hallmarks of macrophage subsets. While LPS-induced classically activated M1 or ...

Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages

Inflammasomes are innate immune signaling platforms that are required for the successful control of many pathogenic organisms, but also promote inflammatory and autoinflammatory diseases. Inflammasomes are activated by cytosolic pattern recognition receptors, including members of the NOD-like receptor (NLR) family. These receptors oligomerize upon the detection of microbial or damage-associated stimuli. Subsequent recruitment of the adaptor protein ASC forms a microscopically visible inflammasome complex, which activates caspase-1 through proximity-induced auto-activation. Following the activation, caspase-1 cleaves pro-IL-1&#946; and pro-IL-18, leading to the activation and secretion of these pro-inflammatory cytokines. Caspase-1 also mediates the inflammatory form of cell death termed pyroptosis, which features the loss of membrane integrity and cell lysis. Caspase-1 cleaves gasdermin D, releasing the N-terminal fragment which forms plasma membrane pores, leading to osmotic lysis.
In vitro, the activation of caspase-1 can be determined by labeling bone marrow-derived macrophages with the caspase-1 activity probe FAM-YVAD-FMK and by labeling the cells with antibodies against the adaptor protein ASC. This technique allows the identification of inflammasome formation and caspase-1 activation in individual cells using fluorescence microscopy. Pyroptotic cell death can be detected by measuring the release of cytosolic lactate dehydrogenase into the medium. This procedure is simple, cost effective and performed in a 96-well plate format, allowing adaptation for screening. In this manuscript, we show that activation of the NLRP3 inflammasome by nigericin leads to the co-localization of the adaptor protein ASC and active caspase-1, leading to pyroptosis.

We describe the detection of NLRP3 inflammasome activation on cellular basis using fluorescence microscopy and staining for active caspase-1 and the adaptor, ASC. A lactate dehydrogenase release assay is presented to detect pyroptotic lysis on a population basis. These techniques can be adapted to study many aspects of inflammasome biology.

Deteção de ativação de Inflammasome e morte celular de Pyroptotic nos macrófagos da medula óssea-derivado murino

Inflammasomes are innate immune signaling platforms that are required for the successful control of many pathogenic organisms, but also promote ...

Isolation and In vitro Culture of Bone Marrow-Derived Macrophages for the Study of NO-Redox Biology

Macrophages are derived from hematopoietic progenitor cells throughout the body, are central to inflammatory processes, and participate in innate and adaptive immune responses. In vitro study of macrophages can be undertaken by ex vivo culture from the peritoneum or through differentiation of myeloid bone marrow progenitor cells to form bone marrow-derived macrophages (BMDMs). A common approach to macrophage differentiation from precursors involves the use of conditioned media from L929 cells (LCM). This media is easy to self-produce but suffers from batch variability, and its constituents are undefined. Similarly, Foetal Bovine Serum (FBS) is used to support growth but contains a vast mixture of undefined molecules that may vary between batches. These methods are not adequate for the study of nitric oxide biology and redox mechanisms as they both contain substantial amounts of small molecules that either interfere with redox mechanisms or supplement levels of cofactors, such as tetrahydrobiopterin (BH4), required for the production of NO from inducible nitric oxide synthase (iNOS). In this report, we present an optimized protocol allowing for control of the NO-redox environment by reducing the levels of exogenous biopterin while maintaining conditions suitable for cell growth and differentiation. Tight control of culture media composition helps ensure experimental reproducibility and facilitates accurate interpretation of results. In this protocol, BMDMs were obtained from a GTP cyclohydrolase (GCH)- deficient mouse model. Culture of BMDMs was performed with media containing either (i) conditioned LCM, or (ii) recombinant M-CSF and GM-CSF to produce minimal artifacts while obtaining BH4 and NO-deficient culture conditions - thus allowing for the reproducible study of NO-redox biology and immunometabolism in vitro.

Isolation and In vitro Culture of Bone Marrow-Derived Macrophages for the Study of NO-Redox Biology

This protocol has been established to culture tetrahydrobiopterin (BH4)- and inducible nitric oxide synthase (iNOS)-deficient primary murine macrophages to study NO-redox biology. The study focuses on reducing potential contamination of BH4 and other artifacts found in traditional isolation and culture methods which may confound experimental outcomes and interpretation of results.

Isolamento e Cultura In vitro de Macrófagos Derivados da Medula Óssea para o Estudo da Biologia NO-Redox

Macrophages are derived from hematopoietic progenitor cells throughout the body, are central to inflammatory processes, and participate in innate and ...