Name: kupffer cell isolation for nanoparticle toxicity testing
Uploaded: 2015-08-18T14:00:00
Description: Watch this Scientific Journal Video about Kupffer Cell Isolation for Nanoparticle Toxicity Testing at JoVE.com

This work was supported by EU FP7-ITN Marie-Curie Network program RADDEL. MB and KAJ would like to acknowledge Joe Varguese and Rui Serra Maia for their help and suggestions along the optimization of the Kupffer cell isolation.

All animal experiments were executed in compliance with all relevant guidelines, regulations and regulatory agencies. The protocol being demonstrated was performed under the guidance and approval of the UK Home office regulation
1. Perfusion and Cell Collection (Figure 1)
<img alt="Figure 1" src="/files/ftp_upload/52989/52989fig1.jpg" /> 
Figure 1: Liver Perfusion. After anaesthesia of the mouse, the digestive tract is laterally moved to the left...

<ol>
	<li>Hoffmann, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performance+of+novel+kidney+biomarkers+in+preclinical+toxicity+studies.">Performance of novel kidney biomarkers in preclinical toxicity studies.</a> Toxicol Sci. 116 (1), 8-22 (2010).</li><li>Nel, 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=Nanomaterial+Toxicity+Testing+in+the+21st+Century:+Use+of+a+Predictive+Toxicological+Approach+and+High-Throughput+Screening.">Nanomaterial Toxicity Testing in the 21st Century: Use of a Predictive Toxicological Approach and High-Throughput Screening.</a> Accounts of Chemical Research. 46 (3), 607-621 (2013).</li><li>Bregoli, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxicity+of+antimony+trioxide+nanoparticles+on+human+hematopoietic+progenitor+cells+and+comparison+to+cell+lines.">Toxicity of antimony trioxide nanoparticles on human hematopoietic progenitor cells and comparison to cell lines.</a> Toxicology. 262 (2), 121-129 (2009).</li><li>Yamasaki, 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=Genomic+Aberrations+and+Cellular+Heterogeneity+in+SV40-Immortalized+Human+Corneal+Epithelial+Cells.">Genomic Aberrations and Cellular Heterogeneity in SV40-Immortalized Human Corneal Epithelial Cells.</a> Investigative Ophthalmology, &amp; Visual Science. 50 (2), 604-613 (2009).</li><li>Motoyoshi, Y., 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=Megalin+contributes+to+the+early+injury+of+proximal+tubule+cells+during+nonselective+proteinuria.">Megalin contributes to the early injury of proximal tubule cells during nonselective proteinuria.</a> Kidney International. 74 (10), 1262-1269 (1038).</li><li>Prozialeck, W. C., Edwards, J. R., Lamar, P. C., Smith, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+barrier+characteristics+and+expression+of+cell+adhesion+molecules+in+proximal+tubule-derived+cell+lines+commonly+used+for+in+vitro+toxicity+studies.">Epithelial barrier characteristics and expression of cell adhesion molecules in proximal tubule-derived cell lines commonly used for in vitro toxicity studies.</a> Toxicology in Vitro. 20 (6), 942-953 (2006).</li><li>Chamberlain, L. M., Godek, M. L., Gonzalez-Juarrero, M., Grainger, D. 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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=M2+Kupffer+Cells+Promote+M1+Kupffer+Cell+Apoptosis:+A+Protective+Mechanism+Against+Alcoholic+and+Nonalcoholic+Fatty+Liver+Disease.">M2 Kupffer Cells Promote M1 Kupffer Cell Apoptosis: A Protective Mechanism Against Alcoholic and Nonalcoholic Fatty Liver Disease.</a> Hepatology. 59 (1), 130-142 (2014).</li><li>Matsuoka, M., Tsukamoto, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimulation+of+hepatic+lipocyte+collagen+production+by+Kupffer+cell-derived+transforming+growth+factor+&#946;:+Implication+for+a+pathogenetic+role+in+alcoholic+liver+fibrogenesis.">Stimulation of hepatic lipocyte collagen production by Kupffer cell-derived transforming growth factor &#946;: Implication for a pathogenetic role in alcoholic liver fibrogenesis.</a> Hepatology. 11 (4), 599-605 (1990).</li><li>Polakos, N. 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=Kupffer+Cell-Dependent+Hepatitis+Occurs+during+Influenza+Infection.">Kupffer Cell-Dependent Hepatitis Occurs during Influenza Infection.</a> The American Journal of Pathology. 168 (4), 1169-1178 (2006).</li><li>Tanner, A., Keyhani, A., Reiner, R., Holdstock, G., Wright, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteolytic+enzymes+released+by+liver+macrophages+may+promote+hepatic+injury+in+a+rat+model+of+hepatic+damage.">Proteolytic enzymes released by liver macrophages may promote hepatic injury in a rat model of hepatic damage.</a> Gastroenterology. 80 (4), 647-654 (1981).</li><li>Knittel, T., 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=Expression+patterns+of+matrix+metalloproteinases+and+their+inhibitors+in+parenchymal+and+non-parenchymal+cells+of+rat+liver:+regulation+by+TNF-&#945;+and+TGF-&#946;1.">Expression patterns of matrix metalloproteinases and their inhibitors in parenchymal and non-parenchymal cells of rat liver: regulation by TNF-&#945; and TGF-&#946;1.</a> Journal of Hepatology. 30 (1), 48-60 (1999).</li><li>Branster, M. 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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=Purification+of+cells+from+livers+of+carcinogen-treated+rats+by+free-flow+electrophoresis.">Purification of cells from livers of carcinogen-treated rats by free-flow electrophoresis.</a> Cancer Res. 43 (9), 4176-4179 (1983).</li><li>Firme, C. P., Bandaru, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxicity+issues+in+the+application+of+carbon+nanotubes+to+biological+systems.">Toxicity issues in the application of carbon nanotubes to biological systems.</a> Nanomedicine. 6 (2), 245-256 (2010).</li><li>Ali-Boucetta, H., Al-Jamal, K. T., Kostarelos, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytotoxic+assessment+of+carbon+nanotube+interaction+with+cell+cultures.">Cytotoxic assessment of carbon nanotube interaction with cell cultures.</a> Methods in Molecular Biology. 726, 299-312 (2011).</li><li>Wang, G., 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=Understanding+and+correcting+for+carbon+nanotube+interferences+with+a+commercial+LDH+cytotoxicity+assay.">Understanding and correcting for carbon nanotube interferences with a commercial LDH cytotoxicity assay.</a> Toxicology. 299 (2-3), 99-111 (2012).</li><li>Wang, J. T. -. W., 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=Magnetically+Decorated+Multiwalled+Carbon+Nanotubes+as+Dual+MRI+and+SPECT+Contrast+Agents.">Magnetically Decorated Multiwalled Carbon Nanotubes as Dual MRI and SPECT Contrast Agents.</a> Advanced Functional Materials. 24 (13), 1880-1894 (2014).</li><li>Li, P. Z., Li, J. Z., Li, M., Gong, J. P., He, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+efficient+method+to+isolate+and+culture+mouse+Kupffer+cells.">An efficient method to isolate and culture mouse Kupffer cells.</a> Immunol Lett. 158 (1-2), 52-56 (2014).</li><li>Froh, M., Konno, A., Thurman, R. G. <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+liver+Kupffer+cells.">Isolation of liver Kupffer cells.</a> Curr Protoc Toxicol. Chapter 14, Unit14 14 (2003).</li></ol>

The following steps are critical to achieve high yield and high viability of Kupffer cells. Aseptic conditions should be used to limit the risk of bacterial and fungal contamination. All instruments need to be sterilized before use. Reagents should be freshly prepared before carrying out the isolation procedure.
The choice of collagenase IV, with low tryptic activity, is crucial. Different lots from the same supplier have different enzymatic activity and they may need to be compared initially ...

The field of nanotoxicology research aims to characterize the biological effect of nanoparticles. Toxicological studies based on in vivo investigations remain the most accurate methods. However, their use is limited by their cost, labor and time requirements1. As alternatives, in vitro assays have been used because of their simplicity and the possibility of developing high-throughput in vitro testing platforms2 - so extending the number of conditions tested. Most nanotoxicological studies are performed using in vitro assays with immortalized cell lines. However, there are concerns regarding the extrapolation of these experimental findings to in vivo toxicological effects3. Indeed, the properties of immortalized cell lines can be significantly different from tissues they were derived from, e.g. genetic transformation4, deterioration of key morphological features5, loss of cellular polarity6 and functional alterations such as the regulation of inflammatory mediators7.
Kupffer cells are the most abundant macrophage population in the body and are directly in contact with blood by lining the wall of liver sinusoids. As part of the reticulo-endothelial system (RES), these macrophages are responsible for the capture of circulating nanoparticles and therefore, constitute a highly suitable model to study nanoparticle toxicity. In vivo8 and in vitro9 studies of inflammatory responses associated with Kupffer cells exposed to nanoparticles have been published elsewhere. Kupffer cells have also been involved in the pathogenesis of liver diseases such as alcoholic liver disease10, liver fibrosis11 or viral hepatitis12. It was reported that isolated Kupffer cells provide useful insight to describe cellular mechanisms involved in liver disruption13,14.
Several methods have been reported to isolate and purify Kupffer cells. Cell isolation can result from mechanical or enzymatic dissociation15. Collagenase digestion shows the advantage of conserving the functional integrity of Kupffer cells, while leading to high Kupffer cell yield16. Many experimental approaches, varying in complexity and costs, have been used to separate Kupffer cells from other liver cell populations. For example, Kupffer cell purity can be achieved by immunoaffinity17, flow electrophoresis18, selective adhesion16 or by centrifugal techniques16, which select cells according to their size and density. A combination of these methods can be chosen to increase the purity of the population16. There is no consensus about the ideal method for Kupffer cell isolation, as it mostly depends on the application and available equipment. However, in the case of nanoparticle toxicity testing, the simplicity and high yield of the technique associated with the functional preservation of Kupffer cells appeared to be most suitable for this application.
The Kupffer cell isolation method reported here is based on a 2-step perfusion method followed by purification on density gradient. The method was modified from the original protocol developed by Smedsr&#248;d et al.16 designed for rat liver cell isolation. Most studies reported and described the isolation of Kupffer cells from rat livers. Herein, we describe a method to isolate Kupffer cells from mouse liver, at a high yield and purity. The use of mice reduces the experiment cost and allows the processing of several livers to obtain large amounts of Kupffer cells for nanoparticle toxicity testing.
In the following protocol, Kupffer cells were incubated with functionalized carbon nanotubes (f-CNTs). The unique physico-chemical properties of CNTs &#8211;i.e. high length to diameter ratio and large surface area, have made CNTs interesting candidates as vectors for therapy and diagnosis purposes. However, concerns have been raised regarding the toxicity of CNTs19, and the development of new in vitro tests aims at increasing the understanding of CNT biological effect. Toxicity in Kupffer cell is associated with a lack of structural integrity of the cell membrane. This is measured by the loss of the cytoplasmic enzyme LDH from the cell into the supernatant. The principle of this method, therefore, is to remove any released LDH and measure what is left in the cells20. This is done in preference to measuring the released LDH in the supernatant because the presence of CNTs in the supernatant interferes with the assay21.
We propose the use of this simple and cost effective Kupffer cell isolation method to isolate high number of functional Kupffer cells. This allows the screening of toxicity of a range of nanoparticles, in a relevant primary macrophage model.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td dir="LTR">Euthatal (pentobarbital sodium)</td>
			<td dir="LTR">Merial</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
		</tr>
		<tr>
			<td dir="LTR">CD1 mice</td>
			<td dir="LTR">Charles River&#160;&#160;</td>
			<td dir="LTR">-</td>
			<td dir="LTR">Mouse weight should vary from 35 to 45 g. We advise the use of male CD1 mice as their weight increase rapidly (e.g. a male CD1 mouse of 7 weeks old exceeds 35 g in weight). It is also advised to contact the animal supplier in advance to arrange for the delivery of older animals. Alternatively animals can be in-house to reach the desired weight.&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">HBSS (Ca2+ and Mg2+ free, with bicarbonate)&#160;&#160;</td>
			<td dir="LTR">Life Technologies&#160;&#160;</td>
			<td dir="LTR">14175-053</td>
			<td dir="LTR">HBSS must be&#160; Ca2+ free.&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Ethylene Glycol Tetraacetic Acid (EGTA) tetrasodium salt&#160;</td>
			<td dir="LTR">Sigma-Aldrich&#160;&#160;</td>
			<td dir="LTR">E8145&#160;&#160;</td>
			<td dir="LTR">EDTA can also be used but EGTA has the advantage of chelating Ca2+ selectively.&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">HEPES (1M)&#160;</td>
			<td dir="LTR">Life Technologies&#160;&#160;</td>
			<td dir="LTR">15630-056&#160;</td>
			<td dir="LTR">100 ml&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Collagenase type IV&#160;</td>
			<td dir="LTR">Worthington&#160;</td>
			<td dir="LTR">CSL-4&#160;</td>
			<td dir="LTR">It is advised to test different batches of collagenase or at least mention to the supplier the product has to be suitable for liver cell isolation&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">&#160;Low glucose DMEM&#160;</td>
			<td dir="LTR">Sigma-Aldrich&#160;&#160;</td>
			<td dir="LTR">D5523&#160;</td>
			<td dir="LTR">500 ml&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">RPMI (with sodium pyruvate and Glutamax&#174;)&#160;</td>
			<td dir="LTR">Life Technologies&#160;&#160;</td>
			<td dir="LTR">12633-012&#160;</td>
			<td dir="LTR">500 ml</td>
		</tr>
		<tr>
			<td dir="LTR">Penicillin/Steptomycin&#160;</td>
			<td dir="LTR">Life Technologies&#160;&#160;</td>
			<td dir="LTR">15140-122</td>
			<td dir="LTR">100 ml</td>
		</tr>
		<tr>
			<td dir="LTR">Fetal Bovine Serum&#160;</td>
			<td dir="LTR">First-Link&#160;&#160;</td>
			<td dir="LTR">60-00-850&#160;</td>
			<td dir="LTR">500 ml&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Trypan blue solution&#160;</td>
			<td dir="LTR">Sigma-Aldrich&#160;</td>
			<td dir="LTR">T8154&#160;</td>
			<td dir="LTR">100 ml&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Coated silica particle solution (Percoll&#174;)</td>
			<td dir="LTR">GE Healtcare&#160;&#160;</td>
			<td dir="LTR">17-0891-02&#160;</td>
			<td dir="LTR">Percoll&#174; is very stable and can be kept for several years&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">1x Phosphate Buffered Saline&#160;&#160;</td>
			<td dir="LTR">Life Technologies&#160;&#160;</td>
			<td dir="LTR">10010-023</td>
			<td dir="LTR">500 ml&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">10x Phosphate Buffered Saline&#160;&#160;</td>
			<td dir="LTR">Life Technologies&#160;&#160;</td>
			<td dir="LTR">70011-036</td>
			<td dir="LTR">500 ml</td>
		</tr>
		<tr>
			<td dir="LTR">Dimethyl sulfoxide&#160;</td>
			<td dir="LTR">Fisher&#160;</td>
			<td dir="LTR">D/4120/PB08&#160;</td>
			<td dir="LTR">500 ml&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">LDH kit (CytoTox 96&#174;)&#160;</td>
			<td dir="LTR">Promega&#160;</td>
			<td dir="LTR">G1781&#160;</td>
			<td dir="LTR">Keep protected from light&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">DMEM phenol red free</td>
			<td dir="LTR">Life Technologies&#160;&#160;</td>
			<td dir="LTR">31053-028&#160;</td>
			<td dir="LTR">500 ml&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">F4/80 antibody (Alexa 488)</td>
			<td dir="LTR">AbD Serotec</td>
			<td dir="LTR">MCA497A488</td>
			<td dir="LTR">Do not dilute, used neat for flow cytometry</td>
		</tr>
		<tr>
			<td dir="LTR">Fluorescent beads</td>
			<td dir="LTR">Sigma</td>
			<td dir="LTR">L2778</td>
			<td dir="LTR">Latex beads, amine-modified polystyrene, fluorescent red. 1 ml</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Name of the Material</td>
			<td>Company&#160;</td>
			<td>Catalog number&#160;</td>
			<td>Comments/Description&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Butterfly blood collection set (23G/305mm long tubing)&#160;&#160;</td>
			<td dir="LTR">BD&#160;</td>
			<td dir="LTR">367288</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Syringe Filters (0.22 &#956;m Blue Rim)&#160;</td>
			<td dir="LTR">Minisart&#160;</td>
			<td dir="LTR">16534-K&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Centrifuge Tubes (50 ml Blue Cap)&#160;</td>
			<td dir="LTR">BD Biosciences, Falcon&#160;</td>
			<td dir="LTR">35 2070&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Petri dish (90 x 15 mm)&#160;</td>
			<td dir="LTR">Thermo Fisher Scientific&#160;&#160;</td>
			<td dir="LTR">BSN 101VR20&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">100 &#956;m cell strainer&#160;&#160;</td>
			<td dir="LTR">BD&#160;&#160;</td>
			<td dir="LTR">352360</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Peristaltic pump&#160;</td>
			<td dir="LTR">Watson Marlow&#160;</td>
			<td dir="LTR">SciQ 300&#160;&#160;</td>
			<td>Rinse tubing before and after each usage with sterile PBS and 70% ethanol.</td>
		</tr>
		<tr>
			<td dir="LTR">24-well plates</td>
			<td dir="LTR">Corning&#160;&#160;</td>
			<td>3526</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">96-well plates&#160;</td>
			<td dir="LTR">Corning&#160;&#160;</td>
			<td dir="LTR">3595</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Centrifuge&#160;</td>
			<td>Eppendorf</td>
			<td>5810R</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Plate reader</td>
			<td>BMG Labtech</td>
			<td>FLUOstar Omega</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Serrefine forceps</td>
			<td>Hammacher GmbH&#160;</td>
			<td>Art. Nr. HSE 004-35 / Cat. Nr. 221-0051</td>
			<td>The serrefine forceps allow to clamp the vessel cannulated with the 23G needle without the need of holding the forceps during the perfusion procedure. URL: (http://www.hammacher.de/Laboratory-Products/Clamps-forceps/Serrefines/HSE-004-35-Serrefine::25126.html)&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Flow cytometry tubes</td>
			<td>BD Biosciences, Falcon&#160;</td>
			<td>352052</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Microcentrifuge tubes (1.5 ml)</td>
			<td>Elkay</td>
			<td>&#160; 000-MICR-150</td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Cell scraper</td>
			<td>BD Biosciences, Falcon</td>
			<td>353086</td>
			<td>Cut blade extremities with a pair of scissors to scrape cells in 24-well plates.</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td dir="LTR">Name of the Reagent</td>
			<td dir="LTR">Company&#160;</td>
			<td dir="LTR">Catalog number&#160;</td>
			<td dir="LTR">Comments/Description&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">&#160;EGTA (Ethylene Glycol Tetraacetic Acid)/HBSS (Hank&#39;s Balanced Salt Solution) Solution&#160;</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR">HBSS containing 0.5 mM EGTA and 25 mM HEPES. Adjust pH to 7.4. Prepare 50 ml for each liver to perfuse.&#160;&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Collagenase Solution&#160;</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR">DMEM low glucose containing collagenase type IV at 100 UI/ml, 15 mM HEPES and 1% Penicllin/Streptamycin (v/v). Adjust pH to 7.4. Prepare 100 ml for each liver to perfuse. After adding the collagenase, it is advised to warm up the solution for 30 min before use. This allows the collagenase activity to be optimum.&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Kupffer Cell Isolation Medium&#160;</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR">RPMI containing, 1% Non-Essential Amino-Acids (v/v),1% glutamax&#174; (v/v) and 1% Penicllin/Streptomycin (v/v). Prepare at least 100 ml for 1-3 livers.&#160;&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Kupffer Cell Culture Medium&#160;</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR">RPMI containing 10% Fetal Bovine Serum, 1% Non-Essential Amino-Acids (v/v),1% Glutamax&#174; (v/v) and 1% Penicllin/Streptamycin (v/v). Prepare at least 100 ml for 1-3 livers.&#160;&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">SIP (solution of isotonic coated silica particles)</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR">Mix 1.7 ml of 10x Phosphate Buffered Saline&#160; with 15.3 ml of Percoll&#174; to obtain 17mL of SIP.</td>
		</tr>
		<tr>
			<td dir="LTR">25% SIP solution&#160;</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR">Mix 5 ml of SIP with 15 ml of 1x Phosphate Buffered Saline&#160;&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">50% SIP solution&#160;</td>
			<td dir="LTR"></td>
			<td></td>
			<td dir="LTR">Mix 10 ml of SIP with 10 ml of 1x Phosphate Buffered Saline&#160;</td>
		</tr>
		<tr>
			<td dir="LTR">Lysis Buffer</td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR">DMEM media with 0.9% Triton X-100</td>
		</tr>
		<tr>
			<td dir="LTR">PBS/BSA Solution</td>
			<td dir="LTR"></td>
			<td></td>
			<td dir="LTR">Prepare fresh Phosphate Buffered Saline pH 7.4 with 1% Bovine Serum Albumin.&#160;</td>
		</tr>
		<tr>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
			<td dir="LTR"></td>
		</tr>
	</tbody>
</table>

kupffer cell isolation for nanoparticle toxicity testing

The large majority of in vitro nanotoxicological studies have used immortalized cell lines for their practicality. However, results from nanoparticle toxicity testing in immortalized cell lines or primary cells have shown discrepancies, highlighting the need to extend the use of primary cells for in vitro assays. This protocol describes the isolation of mouse liver macrophages, named Kupffer cells, and their use to study nanoparticle toxicity. Kupffer cells are the most abundant macrophage population in the body and constitute part of the reticulo-endothelial system (RES), responsible for the capture of circulating nanoparticles. The Kupffer cell isolation method reported here is based on a 2-step perfusion method followed by purification on density gradient. The method, based on collagenase digestion and density centrifugation, is adapted from the original protocol developed by Smedsr&#248;d et al. designed for rat liver cell isolation and provides high yield (up to 14 x 106 cells per mouse) and high purity (&#62;95%) of Kupffer cells. This isolation method does not require sophisticated or expensive equipment and therefore represents an ideal compromise between complexity and cell yield. The use of heavier mice (35-45 g) improves the yield of the isolation method but also facilitates remarkably the procedure of portal vein cannulation. The toxicity of functionalized carbon nanotubes f-CNTs was measured in this model by the modified LDH assay. This method assesses cell viability by measuring the lack of structural integrity of Kupffer cell membrane after incubation with f-CNTs. Toxicity induced by f-CNTs can be measured consistently using this assay, highlighting that isolated Kupffer cells are useful for nanoparticle toxicity testing. The overall understanding of nanotoxicology could benefit from such models, making the nanoparticle selection for clinical translation more efficient.

The number of non-purified parenchymal cells was consistent and ranged between 8 and 14 x 106 cells per mouse (17 isolations were performed). Each mouse isolation was sufficient to plate 16 to 28 wells. Cell viability by trypan blue staining showed cell viability ~95%. Kupffer cells showed a round shape within 30 min of incubation at 37 &#176;C, related to their incomplete adherent morphology (Figure 4A). At 4 hr of incubation and afterwards, cells were spread and cell clusters started to form...

Watch this Scientific Journal Video about Kupffer Cell Isolation for Nanoparticle Toxicity Testing at JoVE.com

Kupffer Cell Isolation for Nanoparticle Toxicity Testing

Liver macrophages, named Kupffer cells, are responsible for the capture of circulating nanoparticles. We describe here a method, of high cell purity and yield, for Kupffer cell isolation. The modified LDH assay is used here to measure the toxicity induced by carbon nanotubes in Kupffer cells.

The large majority of in vitro nanotoxicological studies have used immortalized cell lines for their practicality. However, results from nanoparticle ...

kupffer-cell-isolation-for-nanoparticle-toxicity-testing

Research

JoVE Journal

Immunology and Infection

Isolation of Functional Cardiac Immune Cells

Cardiac immune cells are gaining interest for the roles they play in the pathological remodeling in many cardiac diseases.1-5 These immune cells, which include mast cells, T-cells and macrophages; store and release a variety of biologically active mediators including cytokines and proteases such as tryptase.6-8 These mediators have been shown to be key players in extracellular matrix metabolism by activating matrix metalloproteinases or causing collagen accumulation by modulating the cardiac fibroblasts' function.9-11 However, available techniques for isolating cardiac immune cells have been problematic because they use bacterial collagenase to digest the myocardial tissue. This technique causes activation of the immune cells and thus a loss of function. For example, cardiac mast cells become significantly less responsive to compounds that cause degranulation.12 Therefore, we developed a technique that allows for the isolation of functional cardiac immune cells which would lead to a better understanding of the role of these cells in cardiac disease.13, 14
This method requires a familiarity with the anatomical location of the rat's xiphoid process, axilla and falciform ligament, and pericardium of the heart. These landmarks are important to increase success of the procedure and to ensure a higher yield of cardiac immune cells. These isolated cardiac immune cells can then be used for characterization of functionality, phenotype, maturity, and co-culture experiments with other cardiac cells to gain a better understanding of their interactions.

This method for isolating functional immune cells from the heart provides an alternative to the conventional methods of collagenase digestion, which causes unwanted immune cell activation, resulting in a decreased responsiveness of these cells. Our method of isolation yields functional cardiac immune cells by avoiding problems associated with enzymatic digestion.

Cardiac immune cells are gaining interest for the roles they play in the pathological remodeling in many cardiac diseases.1-5  These immune cells, which ...

Isolation of Precursor B-cell Subsets from Umbilical Cord Blood

Umbilical cord blood is highly enriched for hematopoietic progenitor cells at different lineage commitment stages. We have developed a protocol for isolating precursor B-cells at four different stages of differentiation. Because genes are expressed and epigenetic modifications occur in a tissue specific manner, it is vital to discriminate between tissues and cell types in order to be able to identify alterations in the genome and the epigenome that may lead to the development of disease. This method can be adapted to any type of cell present in umbilical cord blood at any stage of differentiation.	
This method comprises 4 main steps. First, mononuclear cells are separated by density centrifugation. Second, B-cells are enriched using biotin conjugated antibodies that recognize and remove non B-cells from the mononuclear cells. Third the B-cells are fluorescently labeled with cell surface protein antibodies specific to individual stages of B-cell development. Finally, the fluorescently labeled cells are sorted and individual populations are recovered. The recovered cells are of sufficient quantity and quality to be utilized in downstream nucleic acid assays.

Here we describe a protocol for isolating subsets of precursor B-cells from umbilical cord blood. A sufficient quantity and quality of nucleic acids may be extracted from the cells and used in subsequent assays utilizing DNA or RNA.

Umbilical cord blood is highly enriched for hematopoietic progenitor cells at different lineage commitment stages. We have developed a protocol for ...

Detection of Fluorescent Nanoparticle Interactions with Primary Immune Cell Subpopulations by Flow Cytometry

Engineered nanoparticles are endowed with very promising properties for therapeutic and diagnostic purposes. This work describes a fast and reliable method of analysis by flow cytometry to study nanoparticle interaction with immune cells. Primary immune cells can be easily purified from human or mouse tissues by antibody-mediated magnetic isolation. In the first instance, the different cell populations running in a flow cytometer can be distinguished by the forward-scattered light (FSC), which is proportional to cell size, and the side-scattered light (SSC), related to cell internal complexity. Furthermore, fluorescently labeled antibodies against specific cell surface receptors permit the identification of several subpopulations within the same sample. Often, all these features vary when cells are boosted by external stimuli that change their physiological and morphological state. Here, 50 nm FITC-SiO2 nanoparticles are used as a model to identify the internalization of nanostructured materials in human blood immune cells. The cell fluorescence and side-scattered light increase after incubation with nanoparticles allowed us to define time and concentration dependence of nanoparticle-cell interaction. Moreover, such protocol can be extended to investigate Rhodamine-SiO2 nanoparticle interaction with primary microglia, the central nervous system resident immune cells, isolated from mutant mice that specifically express the Green Fluorescent Protein (GFP) in the monocyte/macrophage lineage. Finally, flow cytometry data related to nanoparticle internalization into the cells have been confirmed by confocal microscopy.

Analysis of nanoparticle interaction with defined subpopulations of immune cells by flow cytometry.

Engineered nanoparticles are endowed with very promising properties for therapeutic and diagnostic purposes. This work describes a fast and reliable ...

Lymphocyte Isolation from Human Skin for Phenotypic Analysis and Ex Vivo Cell Culture

Human skin has an important barrier function and contains various immune cells that contribute to tissue homeostasis and protection from pathogens. As the skin is relatively easy to access, it provides an ideal platform to study peripheral immune regulatory mechanisms. Immune resident cells in healthy skin conduct immunosurveillance, but also play an important role in the development of inflammatory skin disorders, such as psoriasis. Despite emerging insights, our understanding of the biology underlying various inflammatory skin diseases is still limited. There is a need for good quality (single) cell populations isolated from biopsied skin samples. So far, isolation procedures have been seriously hampered by a lack of obtaining a sufficient number of viable cells. Isolation and subsequent analysis have also been affected by the loss of immune cell lineage markers, due to the mechanical and chemical stress caused by the current dissociation procedures to obtain single cell suspension. Here, we describe a modified method to isolate T cells from both healthy and involved psoriatic human skin by combining mechanical skin dissociation using an automated tissue dissociator and collagenase treatment. This methodology preserves expression of most immune lineage markers such as CD4, CD8, Foxp3 and CD11c upon the preparation of single cell suspensions. Examples of successful CD4+ T cell isolation and subsequent phenotypic and functional analysis are shown.

Lymphocyte Isolation from Human Skin for Phenotypic Analysis and Ex Vivo Cell Culture

We describe a protocol to efficiently isolate skin resident T cells from human skin biopsies. This protocol yields sufficient numbers of viable human skin resident lymphocytes for flow cytometric analysis and ex vivo culture.

Human skin has an important barrier function and contains various immune cells that contribute to tissue homeostasis and protection from pathogens. As the ...

Whole-animal Imaging and Flow Cytometric Techniques for Analysis of Antigen-specific CD8+ T Cell Responses after Nanoparticle Vaccination

Traditional vaccine adjuvants, such as alum, elicit suboptimal CD8+ T cell responses. To address this major challenge in vaccine development, various nanoparticle systems have been engineered to mimic features of pathogens to improve antigen delivery to draining lymph nodes and increase antigen uptake by antigen-presenting cells, leading to new vaccine formulations optimized for induction of antigen-specific CD8+ T cell responses. In this article, we describe the synthesis of a &#8220;pathogen-mimicking&#8221; nanoparticle system, termed interbilayer-crosslinked multilamellar vesicles (ICMVs) that can serve as an effective vaccine carrier for co-delivery of subunit antigens and immunostimulatory agents and elicitation of potent cytotoxic CD8+ T lymphocyte (CTL) responses. We describe methods for characterizing hydrodynamic size and surface charge of vaccine nanoparticles with dynamic light scattering and zeta potential analyzer and present a confocal microscopy-based procedure to analyze nanoparticle-mediated antigen delivery to draining lymph nodes. Furthermore, we show a new bioluminescence whole-animal imaging technique utilizing adoptive transfer of luciferase-expressing, antigen-specific CD8+ T cells into recipient mice, followed by nanoparticle vaccination, which permits non-invasive interrogation of expansion and trafficking patterns of CTLs in real time. We also describe tetramer staining and flow cytometric analysis of peripheral blood mononuclear cells for longitudinal quantification of endogenous T cell responses in mice vaccinated with nanoparticles.

We describe whole-animal imaging and flow cytometry-based techniques for monitoring expansion of antigen-specific CD8+ T cells in response to immunization with nanoparticles in a murine model of vaccination.

Traditional vaccine adjuvants, such as alum, elicit suboptimal CD8+ T cell responses. To address this major challenge in vaccine development, various ...

Isolation and Flow Cytometric Analysis of Immune Cells from the Ischemic Mouse Brain

Ischemic stroke initiates a robust inflammatory response that starts in the intravascular compartment and involves rapid activation of brain resident cells. A key mechanism of this inflammatory response is the migration of circulating immune cells to the ischemic brain facilitated by chemokine release and increased endothelial adhesion molecule expression. Brain-invading leukocytes are well-known contributing to early-stage secondary ischemic injury, but their significance for the termination of inflammation and later brain repair has only recently been noticed.
Here, a simple protocol for the efficient isolation of immune cells from the ischemic mouse brain is provided. After transcardial perfusion, brain hemispheres are dissected and mechanically dissociated. Enzymatic digestion with Liberase&#160;is followed by density gradient (such as Percoll) centrifugation to remove myelin and cell debris. One major advantage of this protocol is the single-layer density gradient procedure which does not require time-consuming preparation of gradients and can be reliably performed. The approach yields highly reproducible cell counts per brain hemisphere and allows for measuring several flow cytometry panels in one biological replicate. Phenotypic characterization and quantification of brain-invading leukocytes after experimental stroke may contribute to a better understanding of their multifaceted roles in ischemic injury and repair.

Inflammation plays a central role in the pathogenesis of ischemic stroke. Increasing evidence suggests that it acts as a double-edged sword which exacerbates early brain injury, but also contributes to later repair. This protocol describes the isolation of immune cells from the ischemic brain and their subsequent flow cytometric phenotyping.

Ischemic stroke initiates a robust inflammatory response that starts in the intravascular compartment and involves rapid activation of brain resident ...

Isolation, Characterization and Functional Examination of the Gingival Immune Cell Network

Immune cell networks in tissues play a vital role in mediating local immunity and maintaining tissue homeostasis, yet little is known of the resident immune cell populations in the oral mucosa and gingiva. We have established a technique for the isolation and study of immune cells from murine gingival tissues, an area of constant microbial exposure and a vulnerable site to a common inflammatory disease, periodontitis. Our protocol allows for a detailed phenotypic characterization of the immune cell populations resident in the gingiva, even at steady state. Our procedure also yields sufficient cells with high viability for use in functional studies, such as the assessment of cytokine secretion ex vivo. This combination of phenotypic and functional characterization of the gingival immune cell network should aid towards investigating the mechanisms involved in oral immunity and periodontal homeostasis, but will also advance our understanding of the mechanisms involved in local immunopathology.

We have established a technique for the isolation, phenotypic characterization and functional analysis of immune cells from murine gingiva.

Immune cell networks in tissues play a vital role in mediating local immunity and maintaining tissue homeostasis, yet little is known of the resident ...

An Efficient and High Yield Method for Isolation of Mouse Dendritic Cell Subsets

Dendritic cells (DCs) are professional antigen-presenting cells primarily responsible for acquiring, processing and presenting antigens on antigen presenting molecules to initiate T-cell-mediated immunity. Dendritic cells can be separated into several phenotypically and functionally heterogeneous subsets. Three important subsets of splenic dendritic cells are plasmacytoid, CD8&#945;Pos and CD8&#945;Neg cells. The plasmacytoid DCs are natural producers of type I interferon and are important for anti-viral T cell immunity. The CD8&#945;Neg DC subset is specialized for MHC class II antigen presentation and is centrally involved in priming CD4 T cells. The CD8&#945;Pos DCs are primarily responsible for cross-presentation of exogenous antigens and CD8 T cell priming. The CD8&#945;Pos DCs have been demonstrated to be most efficient at the presentation of glycolipid antigens by CD1d molecules to a specialized T cell population known as invariant natural killer T (iNKT) cells. Administration of Flt-3 ligand increases the frequency of migration of dendritic cell progenitors from bone marrow, ultimately resulting in expansion of dendritic cells in peripheral lymphoid organs in murine models. We have adapted this model to purify large numbers of functional dendritic cells for use in cell transfer experiments to compare in vivo proficiency of different DC subsets.

Distinct dendritic cell subsets exist as rare populations in lymphoid organs, and therefore are challenging to isolate in sufficient numbers and purity for immunological experiments. Here we describe a high efficiency, high yield method for isolation of all of the currently known major subsets of mouse splenic dendritic cells.

Dendritic cells (DCs) are professional antigen-presenting cells primarily responsible for acquiring, processing and presenting antigens on antigen ...

Evaluation of the Efficacy And Toxicity of RNAs Targeting HIV-1 Production for Use in Gene or Drug Therapy

Small RNA therapies targeting post-integration steps in the HIV-1 replication cycle are among the top candidates for gene therapy and have the potential to be used as drug therapies for HIV-1 infection. Post-integration inhibitors include ribozymes, short hairpin (sh) RNAs, small interfering (si) RNAs, U1 interference (U1i) RNAs and RNA aptamers. Many of these have been identified using transient co-transfection assays with an HIV-1 expression plasmid and some have advanced to clinical trials. In addition to measures of efficacy, small RNAs have been evaluated for their potential to affect the expression of human RNAs, alter cell growth and/or differentiation, and elicit innate immune responses. In the protocols described here, a set of transient transfection assays designed to evaluate the efficacy and toxicity of RNA molecules targeting post-integration steps in the HIV-1 replication cycle are described. We have used these assays to identify new ribozymes and optimize the format of shRNAs and siRNAs targeting HIV-1 RNA. The methods provide a quick set of assays that are useful for screening new anti-HIV-1 RNAs and could be adapted to screen other post-integration inhibitors of HIV-1 replication.

Methods to evaluate the efficacy and toxicity of RNA molecules targeting post-integration steps of the HIV-1 replication cycle are described. These methods are useful for screening new molecules and optimizing the format of existing ones.

Small RNA therapies targeting post-integration steps in the HIV-1 replication cycle are among the top candidates for gene therapy and have the potential ...

A Silver Nanoparticle Method for Ameliorating Biliary Atresia Syndrome in Mice

Biliary atresia (BA) is a severe type of cholangitis with high mortality in children of which the etiology is still not fully understood. Viral infections may be one possible cause. The typical animal model used for studying BA is established by inoculating a neonatal mouse with a rhesus rotavirus. Silver nanoparticles have been shown to exert antibacterial and antiviral effects; their function in the BA mouse model is evaluated in this study. Currently, in BA animal experiments, the methods used to improve the symptoms of BA mice are generally symptomatic treatments given via food or other drugs. The aim of this study is to demonstrate a new method for ameliorating BA syndrome in mice by the intraperitoneal injection of silver nanoparticles and to provide detailed methods for preparing the silver nanoparticle gel formulation. This method is simple and widely applicable and can be used to research the mechanism of BA, as well as in clinical treatments. Based on the BA mouse model, when the mice exhibit jaundice, the prepared silver nanoparticle gel is injected intraperitoneally to the surface of the lower liver. The survival status is observed, and biochemical indicators and liver histopathology are examined. This method allows a more intuitive understanding of both the establishment of the BA model and novel BA treatments.

This article describes in detail a method based on silver nanoparticles for ameliorating biliary atresia syndrome in an experimental biliary atresia mouse model. A solid understanding of the reagent preparation process and the neonatal mouse injection technique will help familiarize researchers with the method used in neonatal mouse model studies.

Biliary atresia (BA) is a severe type of cholangitis with high mortality in children of which the etiology is still not fully understood. Viral infections ...