The authors would like to thank the volunteers who have contributed clinical material to this study. We are also thankful to the staff at the Department of Public Health and Clinical Medicine, Division of Medicine/Respiratory Medicine, University Hospital, Ume&#229; (Norrlands universitetssjukhus) for the collection of all clinical material.
This work was supported by grants to AS-S from the Swedish Research Council, the Swedish Heart-Lung Foundation, the Swedish Foundation for Strategic Research, and the Karolinska Institutet.

NOTE: This research was approved by the regional Ethical Review Board in Ume&#229;, Sweden.
1. Bronchoscopy for Sampling Endobronchial Biopsies from Human Subjects
<ol>
	<li>Obtain informed consent from all participants.</li>
	<li>Treat subjects with oral midazolam (4-8 mg) and intravenous glycopyrronium (0.2-04 mg) 30 min before the bronchoscopy. Apply topical anesthesia with lidocaine in the larynx and bronchi. Let the subject gargle with ~3 ml of lidocaine 4% and apply 3 ml to the tongue ...

<ol>
	<li>Kopf, M., Schneider, C., Nobs, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+and+function+of+lung-resident+macrophages+and+dendritic+cells.">The development and function of lung-resident macrophages and dendritic cells.</a> Nat Immunol. 16 (1), 36-44 (2015).</li><li>Condon, T. V., Sawyer, R. T., Fenton, M. J., Riches, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lung+dendritic+cells+at+the+innate-adaptive+immune+interface.">Lung dendritic cells at the innate-adaptive immune interface.</a> J Leukoc Biol. 90 (5), 883-895 (2011).</li><li>Lambrecht, B. N., Hammad, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biology+of+lung+dendritic+cells+at+the+origin+of+asthma.">Biology of lung dendritic cells at the origin of asthma.</a> Immunity. 31 (3), 412-424 (2009).</li><li>Schlitzer, A., McGovern, N., Ginhoux, F. <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+monocyte-derived+cells:+Two+complementary+and+integrated+functional+systems.">Dendritic cells and monocyte-derived cells: Two complementary and integrated functional systems.</a> Semin Cell Dev Biol. 41, 9-22 (2015).</li><li>Ziegler-Heitbrock, 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=Nomenclature+of+monocytes+and+dendritic+cells+in+blood.">Nomenclature of monocytes and dendritic cells in blood.</a> Blood. 116 (16), e74-e80 (2010).</li><li>Demedts, I. K., Brusselle, G. G., Vermaelen, K. Y., Pauwels, R. A. <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+human+pulmonary+dendritic+cells.">Identification and characterization of human pulmonary dendritic cells.</a> Am J Respir Cell Mol Biol. 32 (3), 177-184 (2005).</li><li>Donnenberg, V. S., Donnenberg, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+rare-event+detection+and+analysis+of+dendritic+cell+subsets+in+broncho-alveolar+lavage+fluid+and+peripheral+blood+by+flow+cytometry.">Identification rare-event detection and analysis of dendritic cell subsets in broncho-alveolar lavage fluid and peripheral blood by flow cytometry.</a> Front Biosci. 8, s1175-s1180 (2003).</li><li>Masten, B. J., 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=Characterization+of+myeloid+and+plasmacytoid+dendritic+cells+in+human+lung.">Characterization of myeloid and plasmacytoid dendritic cells in human lung.</a> J Immunol. 177 (11), 7784-7793 (2006).</li><li>Ten Berge, 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=A+novel+method+for+isolating+dendritic+cells+from+human+bronchoalveolar+lavage+fluid.">A novel method for isolating dendritic cells from human bronchoalveolar lavage fluid.</a> J Immunol Methods. 351 (1-2), 13-23 (2009).</li><li>Yu, C. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+CD1c++dendritic+cells+drive+the+differentiation+of+CD103++CD8++mucosal+effector+T+cells+via+the+cytokine+TGF-beta.">Human CD1c+ dendritic cells drive the differentiation of CD103+ CD8+ mucosal effector T cells via the cytokine TGF-beta.</a> Immunity. 38 (4), 818-830 (2013).</li><li>Nicod, L. P., Lipscomb, M. F., Toews, G. B., Weissler, 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=Separation+of+potent+and+poorly+functional+human+lung+accessory+cells+based+on+autofluorescence.">Separation of potent and poorly functional human lung accessory cells based on autofluorescence.</a> J Leukoc Biol. 45 (5), 458-465 (1989).</li><li>Sertl, 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=Dendritic+cells+with+antigen-presenting+capability+reside+in+airway+epithelium,+lung+parenchyma,+and+visceral+pleura.">Dendritic cells with antigen-presenting capability reside in airway epithelium, lung parenchyma, and visceral pleura.</a> J Exp Med. 163 (2), 436-451 (1986).</li><li>van Haarst, J. M., de Wit, H. J., Drexhage, H. A., Hoogsteden, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+and+immunophenotype+of+mononuclear+phagocytes+and+dendritic+cells+in+the+human+lung.">Distribution and immunophenotype of mononuclear phagocytes and dendritic cells in the human lung.</a> Am J Respir Cell Mol Biol. 10 (5), 487-492 (1994).</li><li>Schlitzer, 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=IRF4+transcription+factor-dependent+CD11b++dendritic+cells+in+human+and+mouse+control+mucosal+IL-17+cytokine+responses.">IRF4 transcription factor-dependent CD11b+ dendritic cells in human and mouse control mucosal IL-17 cytokine responses.</a> Immunity. 38 (5), 970-983 (2013).</li><li>Yu, Y. 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=Flow+Cytometric+Analysis+of+Myeloid+Cells+in+Human+Blood,+Bronchoalveolar+Lavage,+and+Lung+Tissues.">Flow Cytometric Analysis of Myeloid Cells in Human Blood, Bronchoalveolar Lavage, and Lung Tissues.</a> Am J Respir Cell Mol Biol. , (2015).</li><li>Haniffa, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+tissues+contain+CD141hi+cross-presenting+dendritic+cells+with+functional+homology+to+mouse+CD103++nonlymphoid+dendritic+cells.">Human tissues contain CD141hi cross-presenting dendritic cells with functional homology to mouse CD103+ nonlymphoid dendritic cells.</a> Immunity. 37 (1), 60-73 (2012).</li><li>Britten, K. M., Howarth, P. H., Roche, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunohistochemistry+on+resin+sections:+a+comparison+of+resin+embedding+techniques+for+small+mucosal+biopsies.">Immunohistochemistry on resin sections: a comparison of resin embedding techniques for small mucosal biopsies.</a> Biotech Histochem. 68 (5), 271-280 (1993).</li><li>Perfetto, S. P., Chattopadhyay, P. K., Roederer, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seventeen-colour+flow+cytometry:+unravelling+the+immune+system.">Seventeen-colour flow cytometry: unravelling the immune system.</a> Nat Rev Immunol. 4 (8), 648-655 (2004).</li><li>Baharom, F., 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=Dendritic+Cells+and+Monocytes+with+Distinct+Inflammatory+Responses+Reside+in+Lung+Mucosa+of+Healthy+Humans.">Dendritic Cells and Monocytes with Distinct Inflammatory Responses Reside in Lung Mucosa of Healthy Humans.</a> J Immunol. 196 (11), 4498-4509 (2016).</li><li>Salvi, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+inflammatory+responses+in+the+airways+and+peripheral+blood+after+short-term+exposure+to+diesel+exhaust+in+healthy+human+volunteers.">Acute inflammatory responses in the airways and peripheral blood after short-term exposure to diesel exhaust in healthy human volunteers.</a> Am J Respir Crit Care Med. 159 (3), 702-709 (1999).</li><li>Schon-Hegrad, M. A., Oliver, J., McMenamin, P. G., Holt, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+on+the+density,+distribution,+and+surface+phenotype+of+intraepithelial+class+II+major+histocompatibility+complex+antigen+(Ia)-bearing+dendritic+cells+(DC)+in+the+conducting+airways.">Studies on the density, distribution, and surface phenotype of intraepithelial class II major histocompatibility complex antigen (Ia)-bearing dendritic cells (DC) in the conducting airways.</a> J Exp Med. 173 (6), 1345-1356 (1991).</li><li>Saeys, Y., Gassen, S. V., Lambrecht, B. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computational+flow+cytometry:+helping+to+make+sense+of+high-dimensional+immunology+data.">Computational flow cytometry: helping to make sense of high-dimensional immunology data.</a> Nat Rev Immunol. 16 (7), 449-462 (2016).</li></ol>

The authors declare that they have no competing financial interests.

This paper describes how to generate a detailed spatial and phenotypical characterization of lung tissue-resident DCs in healthy humans using immunohistochemistry and flow cytometry on endobronchial mucosal biopsies collected during bronchoscopy. In the following paragraphs critical steps in the protocol are discussed in detail.
Critical Steps with the Protocol
Sectioning and immunohistochemistry: It is critical to keep the biopsy blocks at -20 &#176;C when not using t...

The lungs are in continuous contact with the external environment and are highly exposed to both harmless particles and microbes with the capacity to cause disease. Therefore, it is critical for the immune system to mount potent immune responses against invading pathogens, but it is equally important to maintain tolerance to inhaled antigens that do not cause disease. To provide potent immune surveillance, the respiratory system is lined with a network of immune cells, including dendritic cells (DCs). DCs are professional antigen-presenting cells with the unique capacity to activate naive T cells. In human lungs, resident DCs encounter an antigen and then process and transport it to the lung-draining lymph nodes for presentation to and activation of T cells1,2,3.
In the human immune system, DCs can be divided into several subsets, with distinct but overlapping functions: CD1c+ and CD141+ myeloid DCs (MDCs) and CD123+ plasmacytoid DCs (PDCs)4,5. While most detailed knowledge on human DCs stems from studies in blood, it is now evident that the human lungs also harbor rare populations of DC subsets with T-cell stimulatory capacity6,7,8,9. However, accumulating data show that immune cells, including DCs, differ in their frequency, phenotype, and function depending on their anatomical location10. Thus, it is important to study immune cells from the relevant tissue to understand their contribution to local immunity and tolerance. Taken together, this underlines the need to study lung-resident DCs when addressing lung diseases, despite blood DCs being more readily available and accessible in humans.
The first studies that investigated lung-resident DCs in humans primarily relied on morphology and the expression of single markers, such as HLA-DR and CD11c, in tissue sections using immunohistochemistry11,12,13. In contrast, more recent studies have typically relied on flow cytometric analyses to study different immune cell subsets. However, since it is difficult to find a single cell-surface marker that uniquely identifies a specific DC subset, the potential limitation of studies applying only four-color flow cytometry is the risk of including cell populations with similar phenotypic markers as DCs. For example, CD11c is expressed on all myeloid DCs and the vast majority of monocytes. On the other hand, in studies applying more advanced flow cytometry panels, non-cancerous lung tissue from surgical resections of patients were typically used10,14,15,16, although it is unclear whether these rare populations are truly representative of DCs present in healthy subjects. Overall, studies are limited largely due to the fact that surgically removed or whole human lung tissue is scarce.
To overcome some of these limitations, this work describes how to perform a detailed analysis of spatial distribution and a phenotypic identification of DCs in mucosal endobronchial biopsies obtained from healthy volunteers who undergo a bronchoscopy. Several small biopsies can be collected from each individual and can subsequently be embedded for sectioning and analysis using immunohistochemistry or enzymatically digested for advanced flow cytometric analysis. Using lung tissue in the form of endobronchial biopsies obtained from bronchoscopies confers the advantage of making it possible to perform the study on healthy volunteers, unlike open surgery of the lungs that, for obvious reasons, is limited to patients that require thoracic surgery. Furthermore, the tissue that is sampled during a bronchoscopy from healthy volunteers is physiologically normal, in contrast to a non-affected area of lung tissue in patients with a pulmonary disease. On the other hand, the biopsies are small and the number of cells retrieved, even when pooling several biopsies, limits the type of analyses that can be performed.
While the present work focuses on DCs, the methods described can be directly expanded to include other (immune) cells of interest that reside in human mucosal lung tissue. Furthermore, the protocols are also directly applicable to samples obtained from patients suffering from pulmonary diseases where bronchoscopy is part of establishing the diagnosis, such as chronic obstructive pulmonary disease (COPD), sarcoidosis, or lung cancer.

<table border="0" cellpadding="0" cellspacing="0" width="1260">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Bronchoscopy</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td style="width:628px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Bronchoscope BF1T160</td>
			<td style="width:172px;">Olympus</td>
			<td style="width:148px;">BF1T160</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Light source&#160;</td>
			<td style="width:172px;">Olympus</td>
			<td style="width:148px;">Exera CV-160</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Fenestrated forceps</td>
			<td style="width:172px;">Olympus</td>
			<td style="width:148px;">FB21C</td>
			<td>Used to take biopsies</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Bite Block</td>
			<td style="width:172px;">Conmed</td>
			<td style="width:148px;">1429</td>
			<td>20x27mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Glucose 25%&#160;</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td>500mL intravenous</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Glycopyrronium bromide 0.2mg/mL</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td>Intravenous. Prevents mucus/saliva secretion</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Mixt. Midazolam 1mg/mL p.o</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td>Can be used for extra relaxation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Lidocaine, 40mg/mL</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td>Mouth and throat administration / Gargled</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Lidocaine 100mg/ml spray</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td>Administered to back of throat</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Lidocaine 20mg/ml spray</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td>Administered via bronchoscope to airways</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Name of Reagent/ Equipment</td>
			<td style="width:172px;">Company</td>
			<td style="width:148px;">Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">GMA processing and embedding</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Glass vials</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td>5mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Acetone</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td style="width:148px;">32201-1L</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Molecular sieves, 4A</td>
			<td style="width:172px;">Alfa Aesar</td>
			<td style="width:148px;">88120</td>
			<td>3-4mm diameter pellets</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Phenylmethylsulfonyl fluoride</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td style="width:148px;">P-7626</td>
			<td>0.035g/100ml acetone</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Iodoacetamide</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td style="width:148px;">I-6125</td>
			<td>0.37g/100ml acetone</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Polythene-flat&#160; TAAB embedding capsules</td>
			<td style="width:172px;">TAAB laboratories</td>
			<td style="width:148px;">C094</td>
			<td>x500 8mm diameter, polythene, flat-bottom capsules</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Capsule holder</td>
			<td style="width:172px;">TAAB laboratories</td>
			<td style="width:148px;">C054</td>
			<td style="width:628px;">Holds 25 8mm capsules</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">JB-4 GMA embedding kit</td>
			<td style="width:172px;">Polysciences</td>
			<td style="width:148px;">00226</td>
			<td>Contains JB-4 Solution A (0026A-800), JB-4 solution B (0026B-3.8), benzoyl peroxide (02618-12)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Methyl benzoate</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td style="width:148px;">27614-1L</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Silica gel with humidity indicator</td>
			<td style="width:172px;">Scharlau</td>
			<td style="width:148px;">GE0043</td>
			<td>2.5-6mm&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Name of Reagent/ Equipment</td>
			<td style="width:172px;">Company</td>
			<td style="width:148px;">Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">GMA sectioning</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Glass microscope slides</td>
			<td style="width:172px;">ThermoFisher Scientific</td>
			<td style="width:148px;">10143562CEF</td>
			<td>Cut edges, frosted end</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Poly-L-Lysine solution</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td style="width:148px;">P8920-500mL</td>
			<td>1:10 for working solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sheet glass strips for ultramicrotomy</td>
			<td>Alkar</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tween 20</td>
			<td>Sigma-Aldrich</td>
			<td>P2287</td>
			<td>Wash solution (0.1% Tween20)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">LKB 7800B Knifemaker</td>
			<td>LKB</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Capsule splitter</td>
			<td style="width:172px;">TAAB laboratories</td>
			<td style="width:148px;">C065</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Carbon steel single edge blades</td>
			<td style="width:172px;">TAAB laboratories</td>
			<td style="width:148px;">B054</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Vice</td>
			<td style="width:172px;"></td>
			<td style="width:148px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Ammonia, 25%</td>
			<td style="width:172px;">VWR</td>
			<td style="width:148px;">1133.1000</td>
			<td>2mL in 1L, 1:500 (0.05%)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Microtome</td>
			<td style="width:172px;">Leica</td>
			<td></td>
			<td>Leica RM 2165</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Light source</td>
			<td style="width:172px;">Leica</td>
			<td></td>
			<td>Leica CLS 150 XE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Microscope with swing arm stand</td>
			<td style="width:172px;">Leica</td>
			<td></td>
			<td>Leica MZ6</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Name of Reagent/ Equipment</td>
			<td style="width:172px;">Company</td>
			<td style="width:148px;">Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">GMA Immunohistochemistry</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Diamond tipped pen</td>
			<td style="width:172px;">Histolab</td>
			<td style="width:148px;">5218</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Hydrogen peroxide 30% solution</td>
			<td style="width:172px;">AnalaR Normapur</td>
			<td style="width:148px;">23619.264</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium azide</td>
			<td>Sigma-Aldrich</td>
			<td>S8032</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tris</td>
			<td>Roche</td>
			<td>10708976001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium chloride</td>
			<td>VWR chemicals</td>
			<td>27810.295</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bovine serum albumin</td>
			<td>Millipore</td>
			<td>82-045-2</td>
			<td>Probumin BSA diagnostic grade</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dulbecco&#39;s modified eagle medium (DMEM)</td>
			<td>Sigma-Aldrich</td>
			<td>D5546</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Anti-human CD45 antibody</td>
			<td>BioLegend</td>
			<td>304002</td>
			<td>Mouse monoclonal, clone HI30, isotype IgG1k. Working concentration of 500 ng/ml</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Anti-human CD1a antibody</td>
			<td>AbD Serotech</td>
			<td>MCA80GA</td>
			<td>Mouse monoclonal, clone NA1/34-HLK, isotype IgG2a. Working concentration of 10 &#181;g/ml</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mouse monoclonal IgG1 isotype control</td>
			<td>Abcam</td>
			<td>ab27479</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mouse monoclonal IgG2a isotype control</td>
			<td>Dako</td>
			<td>X094301-2</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vectastain ABC Elite standard kit</td>
			<td>Vector Labs</td>
			<td>PK-6100</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:312px;">AEC (3-amino-9-ethylcarbazole) peroxidase substrate kite</td>
			<td style="width:172px;">Vector Labs</td>
			<td style="width:148px;">SK-4200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Mayers haematoxylin</td>
			<td style="width:172px;">HistoLab</td>
			<td style="width:148px;">01820</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Permanent Aqueous Mounting Medium</td>
			<td style="width:172px;">AbD Serotech</td>
			<td style="width:148px;">BUF058C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Drying oven</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">DPX permanent mounting solution&#160;</td>
			<td style="width:172px;">VWR</td>
			<td style="width:148px;">360292F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Light microscope</td>
			<td style="width:172px;">Leica</td>
			<td></td>
			<td>Leica DMLB</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Microscope camera</td>
			<td style="width:172px;">Leica</td>
			<td></td>
			<td>Leica DFC 320</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Analysis software</td>
			<td style="width:172px;">Leica</td>
			<td></td>
			<td>Leica Qwin V3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Name of Reagent/ Equipment</td>
			<td style="width:172px;">Company</td>
			<td style="width:148px;">Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Enzymatic digestion</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Hank&#39;s Balanced Salt Solution (HBSS)</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td>55021C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Dithiothreitol (DTT)</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td>DTT-RO</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Collagenase II</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td>C6885</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">DNase</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td>10104159001&#160;ROCHE</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">RPMI 1640</td>
			<td style="width:172px;">Sigma-Aldrich</td>
			<td>R8758</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Forceps</td>
			<td style="width:172px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Platform rocker</td>
			<td style="width:172px;">Grant instruments</td>
			<td>PMR-30</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">50 mL conical tubes</td>
			<td style="width:172px;">Falcon</td>
			<td>14-432-22</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">40 &#181;m cell strainer</td>
			<td style="width:172px;">Falcon</td>
			<td>352340</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Name of Reagent/ Equipment</td>
			<td style="width:172px;">Company</td>
			<td style="width:148px;">Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Flow cytometry</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Phosphate Buffered Saline (PBS)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">LIVE/DEAD Aqua fixable dead cell stain kit</td>
			<td>Life Technologies</td>
			<td>L34957</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD45</td>
			<td>BD</td>
			<td>555485</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD3</td>
			<td>BD</td>
			<td>557757</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD20</td>
			<td>BD</td>
			<td>335829</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD56</td>
			<td>Biolegend</td>
			<td>318332</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD66abce</td>
			<td>Miltenyi</td>
			<td>130-101-132</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">HLA-DR</td>
			<td>BD</td>
			<td>555813</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD14</td>
			<td>BD</td>
			<td>557831</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD16</td>
			<td>Biolegend</td>
			<td>302026</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD11c</td>
			<td>BD</td>
			<td>560369</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD1c</td>
			<td>Miltenyi</td>
			<td>130-098-009</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD141</td>
			<td>Miltenyi</td>
			<td>130-090-514</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">CD103</td>
			<td>Biolegend</td>
			<td>350212</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">Paraformaldehyde</td>
			<td>Sigma-Aldrich</td>
			<td>F8775</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">LSR II Flow cytometer</td>
			<td>BD</td>
			<td></td>
			<td>Flow cytometer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:312px;">FlowJo</td>
			<td>FlowJo</td>
			<td></td>
			<td>Software for analysis</td>
		</tr>
	</tbody>
</table>

human lung dendritic cells: spatial distribution and phenotypic identification in endobronchial biopsies using immunohistochemistry and flow cytometry

The lungs are constantly exposed to the external environment, which in addition to harmless particles, also contains pathogens, allergens, and toxins. In order to maintain tolerance or to induce an immune response, the immune system must appropriately handle inhaled antigens. Lung dendritic cells (DCs) are essential in maintaining a delicate balance to initiate immunity when required without causing collateral damage to the lungs due to an exaggerated inflammatory response. While there is a detailed understanding of the phenotype and function of immune cells such as DCs in human blood, the knowledge of these cells in less accessible tissues, such as the lungs, is much more limited, since studies of human lung tissue samples, especially from healthy individuals, are scarce. This work presents a strategy to generate detailed spatial and phenotypic characterization of lung tissue resident DCs in healthy humans that undergo a bronchoscopy for the sampling of endobronchial biopsies. Several small biopsies can be collected from each individual and can be subsequently embedded for ultrafine sectioning or enzymatically digested for advanced flow cytometric analysis. The outlined protocols have been optimized to yield maximum information from small tissue samples that, under steady-state conditions, contain only a low frequency of DCs. While the present work focuses on DCs, the methods described can directly be expanded to include other (immune) cells of interest found in mucosal lung tissue. Furthermore, the protocols are also directly applicable to samples obtained from patients suffering from pulmonary diseases where bronchoscopy is part of establishing the diagnosis, such as chronic obstructive pulmonary disease (COPD), sarcoidosis, or lung cancer.

Studies characterizing human respiratory tissue-resident immune cells, including DCs, are limited, largely due to the fact that surgically removed or whole human lung tissue is scarce. Here, a less invasive method of obtaining lung tissue from endobronchial biopsies (EBB) of healthy volunteers and developed protocols to study the immune cells in the tissue using immunohistochemistry or flow cytometry are outlined.
Healthy volunt...

Watch this Scientific Journal Video about Human Lung Dendritic Cells: Spatial Distribution and Phenotypic Identification in Endobronchial Biopsies Using Immunohistochemistry and Flow Cytometry at JoVE

Human Lung Dendritic Cells: Spatial Distribution and Phenotypic Identification in Endobronchial Biopsies Using Immunohistochemistry and Flow Cytometry

Lung-resident immune cells, including dendritic cells (DCs) in humans, are critical for defense against inhaled pathogens and allergens. However, due to the scarcity of human lung tissue, studies are limited. This work presents protocols to process human mucosal endobronchial biopsies for studying lung DCs using immunohistochemistry and flow cytometry.

The lungs are constantly exposed to the external environment, which in addition to harmless particles, also contains pathogens, allergens, and toxins. In ...

The main advantage of this technique is that a lot of information can be generated from small tissues obtained during bronchoscopy.This method can help answer key questions in mucosal immunology, where bronchoscopy is part of establishing the diagnosis, such as COPD, sarcoidosis, or lung cancer.Visual demonstration of this procedure will enable individuals new to this method to recognize when enzymatic digestion is complete.Demonstrating this procedure, along with Faezzah Baharom, will be Greg Rankin, a postdoc from our collaborator's lab at Ume

human-lung-dendritic-cells-spatial-distribution-phenotypic

Research

JoVE Journal

Immunology and Infection

9.1K Görüntüleme.  Karolinska Institutet. The main advantage of this technique is that a lot of information can be generated from small tissues obtained during bronchoscopy.This method can help answer key questions in mucosal immunology, where bronchoscopy is part of establishing the diagnosis, such as COPD, sarcoidosis, or lung cancer.Visual demonstration of this procedure will enable individuals new to this method to recognize when enzymatic digestion is complete.Demonstrating this procedure, along with Faezzah Baharom, will be Gre...

Video: Human Lung Dendritic Cells: Spatial Distribution and Phenotypic Identification in Endobronchial Biopsies Using Immunohistochemistry and Flow Cytometry