We thank Steve McBryant and Jeff Hansen for help with ultracentrifugation and Patti Kiser for help with mouse handling. The National Institute of Neurological Diseases and Stroke at the National Institutes of Health, grant 5R01NS056379-02 funded this work.

1. Purifying and Labeling Prion Rods
This protocol is adapted from one previously published 18
<ol>
<li>Homogenize 100 grams of prion-infected brain tissue in 900 mL of ice cold homogenizing buffer (HB, 1X PBS containing 320 mM sucrose, 150 mM NaCl and 4mM EDTA) 1 min at maximum speed in a commercial blender, then 2 min on ice. Repeat three times.</li>
<li>Centrifuge homogenate for 10 min at 3000 x g and 4&deg;C. Remove and save supernatant on ice. Re-suspend pellet in 1L...

<ol>
	<li>Klein, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+crucial+role+for+B+cells+in+neuroinvasive+scrapie.">A crucial role for B cells in neuroinvasive scrapie.</a> Nature. 390, 687-687 (1997).</li><li>Mabbott, N. A., Farquhar, C. F., Brown, K. L., Bruce, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+the+immune+system+in+TSE+pathogenesis.">Involvement of the immune system in TSE pathogenesis.</a> Immunol Today. 19, 201-201 (1998).</li><li>Sigurdson, C. 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P., MacPherson, G. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dendritic+cells+and+oral+transmission+of+prion+diseases.">Dendritic cells and oral transmission of prion diseases.</a> Adv Drug Deliv Rev. 56, 901-901 (2004).</li><li>Ano, Y., Sakudo, A., Nakayama, H., Onodera, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uptake+and+dynamics+of+infectious+prion+protein+in+the+intestine.">Uptake and dynamics of infectious prion protein in the intestine.</a> Protein Pept Lett. 16, 247-247 (2009).</li><li>Aucouturier, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infected+splenic+dendritic+cells+are+sufficient+for+prion+transmission+to+the+CNS+in+mouse+scrapie.">Infected splenic dendritic cells are sufficient for prion transmission to the CNS in mouse scrapie.</a> J Clin Invest. 108, 703-703 (2001).</li><li>Huang, F. 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Here we demonstrate a protocol for tagging and tracking prions in vivo that greatly facilitates monitoring early events in peripheral prion infection. This protocol greatly improves on past attempts at monitoring prion uptake in vitro 9 and in vivo 3,12 by pre-labeling highly enriched prion inoculum to unambiguously differentiate it from endogenous PrPC. Because infectious prions and PrPC share the same primary amino acid sequence, generating prion-...

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		<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>CWD-infected elk brain</td>
<td>&nbsp;</td>
<td>Private elk farm in Colorado</td>
<td>&nbsp;</td>
<td>Use any non-human prion-infected brain</td>
</tr>
<tr>
<td>Blender</td>
<td>&nbsp;</td>
<td>Oster</td>
<td>6694-015</td>
<td>Use any commercial blender</td>
</tr>
<tr>
<td>Centrifuge</td>
<td>&nbsp;</td>
<td>Sorvall</td>
<td>SS34 rotor</td>
<td>Use any centrifuge /rotor that can reach 3000 x g and hold &ge; 500 ml volumes</td>
</tr>
<tr>
<td>Ultracentrifuge</td>
<td>&nbsp;</td>
<td>Beckman</td>
<td>50.2 Ti rotor</td>
<td>Use any ultracentrifuge /rotor that can reach 100,000 x g and hold &ge; 500 ml volumes</td>
</tr>
<tr>
<td>Bradford Reagent</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>B6916</td>
<td>&nbsp;</td>
<tr>
<td>Complete mini protease inhibitor cocktail</td>
<td>&nbsp;</td>
<td>Roche</td>
<td>11 836 170 001</td>
<td>&nbsp;</td>
<tr>
<td>Sonicator</td>
<td>&nbsp;</td>
<td>Misonix</td>
<td>MP4000X</td>
<td>Use any horn or probe sonicator set to ~70% max power</td>
</tr>
<tr>
<td>DyLight antibody Labeling kit</td>
<td>&nbsp;</td>
<td>Thermo Scientific</td>
<td>53050</td>
<td>&nbsp;</td>
<tr>
<td>microcentrifuge</td>
<td>&nbsp;</td>
<td>Eppendorf</td>
<td>55430R</td>
<td>Use any refrigerated microcentrifuge that can achieve 13,000x g</td>
</tr>
<tr>
<td>centrifugal filter columns</td>
<td>&nbsp;</td>
<td>Millipore</td>
<td>Microcon YM-100</td>
<td>Use any filter or dialysis membrane with 100 Kd molecular weight cutoff</td>
</tr>
<tr>
<td>8-40 week-old FVB mice</td>
<td>&nbsp;</td>
<td>Charles River</td>
<td>207</td>
<td>Use any inbred mouse strain</td>
</tr>
<tr>
<td>1 &mu;m red fluorescent beads</td>
<td>&nbsp;</td>
<td>Phosphorex</td>
<td>2307</td>
<td>Use any fluorescent bead &le; 10 &mu;m</td>
</tr>
<tr>
<td>RPMI 1640 medium </td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>11875-093</td>
<td>&nbsp;</td>
<tr>
<td>40 &mu;m cell strainer</td>
<td>&nbsp;</td>
<td>Falcon</td>
<td>352340</td>
<td>&nbsp;</td>
<tr>
<td>fluorescent antibodies</td>
<td>&nbsp;</td>
<td>BD pharmingen</td>
<td>Various</td>
<td>Use any fluorescent antibody appropriate for your application.</td>
</tr>
<tr>
<td>flow cytometer</td>
<td>&nbsp;</td>
<td>Dakocytomation</td>
<td>CyanADP</td>
<td>Use any flow cytometer capable of multicolor fluorescence detection</td>
</tr>		</tbody>
		</table>
		</div>

monitoring immune cells trafficking fluorescent prion rods hours after intraperitoneal infection

Presence of an abnormal form a host-encoded prion protein (PrPC) that is protease resistant, pathologic and infectious characterizes prion diseases such as Chronic Wasting Disease (CWD) of cervids and scrapie in sheep. The Prion hypothesis asserts that this abnormal conformer constitutes most or all of the infectious prion. The role of the immune system in early events in peripheral prion pathogenesis has been convincingly demonstrated for CWD and scrapie 1-3. Transgenic and pharmacologic studies in mice revealed an important role of the Complement system in retaining and replicating prions early after infection 4-6. In vitro and in vivo studies have also observed prion retention by dendritic cells 7-10, although their role in trafficking remains unclear 11-16. Macrophages have similarly been implicated in early prion pathogenesis, but these studies have focused on events occurring weeks after infection 3,11,17. These prior studies also suffer from the problem of differentiating between endogenous PrPC and infectious prions. Here we describe a semiquantitative, unbiased approach for assessing prion uptake and trafficking from the inoculation site by immune cells recruited there. Aggregated prion rods were purified from infected brain homogenate by detergent solubilization of non-aggregated proteins and ultracentrifugation through a sucrose cushion. Polyacrylamide gel electrophoresis, coomassie blue staining and western blotting confirmed recovery of highly enriched prion rods in the pelleted fraction. Prion rods were fluorochrome-labeled then injected intraperitoneally into mice. Two hours later immune cells from peritoneal lavage fluid, spleen and mediastinal and mesenteric lymph nodes were assayed for prion rod retention and cell subsets identified by multicolor flow cytometry using markers for monocytes, neutrophils, dendritic cells, macrophages and B and T cells. This assay allows for the first time direct monitoring of immune cells acquiring and trafficking prions in vivo within hours after infection. This assay also clearly differentiates infectious, aggregated prions from PrPC normally expressed on host cells, which can be difficult and lead to data interpretation problems in other assay systems. This protocol can be adapted to other inoculation routes (oral, intravenous, intranervous and subcutaneous, e.g.) and antigens (conjugated beads, bacterial, viral and parasitic pathogens and proteins, egg) as well.

Watch this Scientific Journal Video about Monitoring Immune Cells Trafficking Fluorescent Prion Rods Hours after Intraperitoneal Infection at JoVE.com

Monitoring Immune Cells Trafficking Fluorescent Prion Rods Hours after Intraperitoneal Infection

Here we describe a novel assay for monitoring prion uptake and trafficking by immune cells immediately following intraperitoneal inoculation by purifying and fluorescently labeling aggregated prion rods from infected brain material then monitoring their uptake and movement from the injection site and characterizing the cells mediating these events.

Presence of an abnormal form a host-encoded prion protein (PrPC) that is protease resistant, pathologic and infectious characterizes prion diseases such ...

monitoring-immune-cells-trafficking-fluorescent-prion-rods-hours

Research

JoVE Journal

Immunology and Infection

11.4K visualizações.  Colorado State University. Aqui nós descrevemos um ensaio de romance para o monitoramento e captação de prion tráfico por células do sistema imunológico imediatamente após a inoculação intraperitoneal de purificação e fluorescente rotulagem varas prion agregados de material cerebral infectado acompanhamento da sua absorção e movimento a partir do local da injeção e caracterizar as células mediadoras desses eventos.