We are grateful to the surgeons of the Department of Thoracic and Cardiovascular Surgery, University Clinic Tuebingen for providing us with the thymus samples and Bruno Kyewski (DKFZ, Heidelberg, Germany) for providing the CDR2 antibody. We would also like to thank Hans-J&#246;rg B&#252;hring and Sabrina Grimm from the sorting facility (University of Tuebingen). This work was supported by the SFB 685 and the Hertie Foundation.

<ol>
	<li>Miller, J. F. A. 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+discovery+of+thymus+function+and+of+thymus-derived+lymphocytes.">The discovery of thymus function and of thymus-derived lymphocytes.</a> Immunological Reviews. 185, 7-14 (2002).</li><li>Klein, L., Hinterberger, M., Wirnsberger, G., Kyewski, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antigen+presentation+in+the+thymus+for+positive+selection+and+central+tolerance+induction.">Antigen presentation in the thymus for positive selection and central tolerance induction.</a> Nat Rev Immunol. 9, 833-844 (2009).</li><li>Vandenabeele, S., Hochrein, H., Mavaddat, N., Winkel, K., Shortman, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+thymus+contains+2+distinct+dendritic+cell+populations.">Human thymus contains 2 distinct dendritic cell populations.</a> Blood. 97, 1733-1741 (2001).</li><li>Gotter, J., Brors, B., Hergenhahn, M., Kyewski, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Medullary+Epithelial+Cells+of+the+Human+Thymus+Express+a+Highly+Diverse+Selection+of+Tissue-specific+Genes+Colocalized+in+Chromosomal+Clusters.">Medullary Epithelial Cells of the Human Thymus Express a Highly Diverse Selection of Tissue-specific Genes Colocalized in Chromosomal Clusters.</a> The Journal of Experimental Medicine. 199, 155-166 (2004).</li><li>Rouse, R. V., Bolin, L. M., Bender, J. R., Kyewski, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monoclonal+antibodies+reactive+with+subsets+of+mouse+and+human+thymic+epithelial+cells.">Monoclonal antibodies reactive with subsets of mouse and human thymic epithelial cells.</a> Journal of Histochemistry &amp; Cytochemistry. 36, 1511-1517 (1988).</li><li>Stoeckle, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cathepsin+S+dominates+autoantigen+processing+in+human+thymic+dendritic+cells.">Cathepsin S dominates autoantigen processing in human thymic dendritic cells.</a> Journal of Autoimmunity. 38, 332-343 (2012).</li><li>Woods Ignatoski, K. M., Bingham, E. L., Frome, L. K., Doherty, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Directed+trans-differentiation+of+thymus+cells+into+parathyroid-like+cells+without+genetic+manipulation.">Directed trans-differentiation of thymus cells into parathyroid-like cells without genetic manipulation.</a> Tissue Eng Part C Methods. 17, 1051-1059 (2011).</li><li>Williams, K. 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=Single+Cell+Analysis+of+Complex+Thymus+Stromal+Cell+Populations:+Rapid+Thymic+Epithelia+Preparation+Characterizes+Radiation+Injury.">Single Cell Analysis of Complex Thymus Stromal Cell Populations: Rapid Thymic Epithelia Preparation Characterizes Radiation Injury.</a> Clinical and Translational Science. 2, 279-285 (2009).</li><li>Bendriss-Vermare, N., 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+thymus+contains+IFN-&#945;-producing+CD11c-,+myeloid+CD11c+,+and+mature+interdigitating+dendritic+cells.">Human thymus contains IFN-&#945;-producing CD11c-, myeloid CD11c+, and mature interdigitating dendritic cells.</a> The Journal of Clinical Investigation. 107, 835-844 (2001).</li><li>Schmitt, N., 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=Ex+vivo+characterization+of+human+thymic+dendritic+cell+subsets.">Ex vivo characterization of human thymic dendritic cell subsets.</a> Immunobiology. 212, 167-177 (2007).</li><li>Dzionek, 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=BDCA-4:+Three+Markers+for+Distinct+Subsets+of+Dendritic+Cells+in+Human+Peripheral+Blood.">BDCA-4: Three Markers for Distinct Subsets of Dendritic Cells in Human Peripheral Blood.</a> The Journal of Immunology. 165, 6037-6046 (2000).</li><li>Wu, L., Shortman, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterogeneity+of+thymic+dendritic+cells.">Heterogeneity of thymic dendritic cells.</a> Seminars in Immunology. 17, 304-312 (2005).</li><li>Seach, N., Wong, K., Hammett, M., Boyd, R. L., Chidgey, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purified+enzymes+improve+isolation+and+characterization+of+the+adult+thymic+epithelium.">Purified enzymes improve isolation and characterization of the adult thymic epithelium.</a> Journal of Immunological Methods. 385, 23-34 (2012).</li><li>Adamopoulou, E., Tenzer, S., Hillen, N., Klug, P., Rota, I. A., Tietz, S., Gebhardt, M., Stevanovic, S., Schild, 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=Exploring+the+MHC-peptide+matrix+of+central+tolerance+in+the+human+thymus.">Exploring the MHC-peptide matrix of central tolerance in the human thymus.</a> Nature Communications. , (2013).</li></ol>

No conflict of interest declared.

The protocol described here is a modification of the protocol published by Gotter et al4. Critical steps in the protocol are the condition and initial preparation of the tissue as well as the Percoll density separation. We strongly recommend to process the tissue as soon as possible after collection. It is important to work fast but thoroughly when cleaning and cutting the tissue. During the thymocyte wash described in step 2.3, it is crucial to find the right balance when applying pressure with the b...

The thymus is the organ in which T cell development occurs. Its relative and absolute size decreases with age when it becomes successively replaced by fat although thymic activity can still be detected in the old age. Its importance for the immune response was demonstrated in the early 1960s1.
The T cell repertoire is shaped through the interaction of T cell receptors with peptide-MHC complexes on different kinds of thymic APC, which provide survival or death cues to developing T cells, resulting in a functional and largely self-tolerant T cell repertoire2.
Approximately 98% of the cells in the human thymus are developing T cells referred to as thymocytes. The remaining 2% consist of a number of different cell types, including a variety of TEC (cortical, medullary, subcapsular), myeloid and plasmacytoid DC (mDC, pDC), macrophages, B cells, mature re-circulating T cells, granulocytes, fibroblasts, endothelial cells and very rare epithelial cells with an expression phenotype resembling that of cells from other tissues such as muscle, neurons and respiratory epithelium (Figure 1). Of these, TEC and DC are the major APC types found in a normal thymus. In recent years, purification of these APC types for culture and molecular profiling has gained more and more interest. Due to their low frequency, isolation of any of these cell types for detailed analysis requires an efficient, reproducible and cost-effective procedure. The method presented here is a modification from previously published studies3,4.
As with any other tissue, cell extraction from the thymus can be achieved by enzymatically disaggregating the cell-cell and cell-matrix interaction networks, in order to obtain a suspension of single cells. There are certain parameters like good dissociation efficiency, cell yield, cell viability and retention of cell surface markers that are crucial and need to be optimized for the successful isolation of these rare cell populations.
In this protocol, isolation of DC and TEC subsets is performed by making a single-cell suspension of the tissue by mechanical disruption and enzymatic digestion. We use Collagenase A from Clostridium histolyticum, which has a balanced ratio of different enzyme activities, to break down the native collagen that holds the tissue together. DNase I is included in the enzyme solution to reduce cell aggregation due to free DNA from dead cells (thymocytes are very sensitive).We also provide an alternative approach to the typical enzymatic tissue digestion involving mechanical and enzymatic tissue treatment assisted by a tissue dissociator. The single cell suspension is then subjected to a single Percoll density centrifugation for enrichment of low density fraction (LDF) of cells. From this fraction of cells, DC can be isolated by staining for DC-surface markers (i.e. CD11c+) and using magnetic separation or fluorescence-activated cell sorting (FACS). Unlike the lymphoid cells comprising the vast majority of cells in the thymus, TEC do not express CD45 at high levels, but are positive for the epithelial cell adhesion molecule EpCAM. cTEC can be distinguished from medullary TEC by the expression of a yet undefined antigen recognized by the CDR-2 (cortical dendritic reticulocyte-2) antibody4,5 and somewhat lower EpCAM expression. The differential co-expression of EpCAM and CDR2 allows the efficient isolation of these TEC subsets via high-speed cell sorting6.
The protocol presented here is optimized for human thymic tissue. The duration of the procedure depends on the amount of tissue and the ability of the experimenter as well as the speed of the cell sorter, if FACS sorting is used. Normally, the protocol for the isolation of DC can be completed within 5-6 hr and for the isolation of TEC in 8-10 hr. The isolation of DC and TEC subsets from thymic tissue is time sensitive. The faster the isolation procedure, the better the condition of the cells. Finally, the isolated cells can be used for further investigations like comparative studies of mRNA and protein expression, PCR experiments, protein isolation, molecular profiling (i.e. transcriptomics, micro RNA analysis) as well as cell culture6.
Ethics Statement
In order to be able to work with human thymus tissue the researcher needs to obtain approval from the local ethics committee or responsible authorities as well as an informed written consent of the donor (or usually his or her parents, since tissue is usually obtained from underage children). Furthermore, all human tissues should be handled as being potentially infectious and appropriate measures should be taken, such as working with gloves, etc.

<table border="1">
	<tbody>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Reagents and Materials</td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>PAA</td>
			<td>E15-842</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s PBS</td>
			<td>PAA</td>
			<td>H15-002</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum-Gold</td>
			<td>PAA</td>
			<td>A15-151</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin</td>
			<td>PAA</td>
			<td>K41-001</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase A</td>
			<td>Roche</td>
			<td>10 103 586 001</td>
			<td></td>
		</tr>
		<tr>
			<td>DNase I, grade II bovine pancreatic</td>
			<td>Roche</td>
			<td>10 104 159 001</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA 10x in PBS</td>
			<td>PAA</td>
			<td>L11-001</td>
			<td>stock conc. 20 mg/ml</td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 Protein Labelling kit</td>
			<td>Molecular Probes</td>
			<td>A-10235</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-human CDR2 (purified)</td>
			<td>Bruno Kyewski, DKFZ- Heidelberg, Germany</td>
			<td></td>
			<td>labeled with Alexa Fluor 488</td>
		</tr>
		<tr>
			<td>anti-human CD45 (Pacific Blue)</td>
			<td>Biolegend</td>
			<td>304022</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-human EpCAM (APC)</td>
			<td>Miltenyi Biotec</td>
			<td>130-091-254</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-human CD11c (PE)</td>
			<td>Miltenyi Biotec</td>
			<td>130-092-411</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-PE Microbeads</td>
			<td>Miltenyi Biotec</td>
			<td>130-048-801</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-CD45 Microbeads, human</td>
			<td>Miltenyi Biotec</td>
			<td>130-045-801</td>
			<td></td>
		</tr>
		<tr>
			<td>LS columns</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-401</td>
			<td></td>
		</tr>
		<tr>
			<td>gentleMACS C Tubes</td>
			<td>Miltenyi Biotec</td>
			<td>130-093-237</td>
			<td>for tissue dissociator</td>
		</tr>
		<tr>
			<td>Percoll (density 1.130 g/ml)</td>
			<td>GE Healthcare, Life Sciences</td>
			<td>17-0891-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile distilled Water (DNAse/ RNAse free)</td>
			<td>GIBCO</td>
			<td>10977-035</td>
			<td></td>
		</tr>
		<tr>
			<td>Gamunex 10%</td>
			<td>Tajecris-Biotherapeutics</td>
			<td>G120052</td>
			<td>1:10 pre-dilution, use 20 &#956;l/1 x 106cells</td>
		</tr>
		<tr>
			<td>0.22 &#956;m filter</td>
			<td>Millex GS</td>
			<td>SLGS033SS</td>
			<td>Syringe driven</td>
		</tr>
		<tr>
			<td>Stericup filter unit</td>
			<td>Millipore</td>
			<td>SCGPU05RE</td>
			<td>Pump driven</td>
		</tr>
		<tr>
			<td>50 ml PC oak ridge centrifuge tubes</td>
			<td>Nalgene</td>
			<td>3118-0050</td>
			<td>50 ml</td>
		</tr>
		<tr>
			<td>50 ml PP conical tubes</td>
			<td>Becton Dickinson</td>
			<td>352070</td>
			<td></td>
		</tr>
		<tr>
			<td>12 mm x 75 mm 5 ml test tubes</td>
			<td>Becton Dickinson</td>
			<td>352058</td>
			<td>FACS stainings</td>
		</tr>
		<tr>
			<td>Cell strainer 70 &#956;m</td>
			<td>Becton Dickinson</td>
			<td>352350</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>INSTRUMENTS</td>
		</tr>
		<tr>
			<td>Flow Cytometer-Sorter (BD FACSAriaTMIIu)</td>
			<td>Becton Dickinson</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sorvall Evolution R6 (rotor)</td>
			<td>Kendro</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Rotator REAX 2</td>
			<td>Heidolph</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>gentleMACS Dissociator</td>
			<td>Miltenyi Biotec</td>
			<td>130-093 235</td>
			<td>tissue dissociator</td>
		</tr>
	</tbody>
</table>

isolation of myeloid dendritic cells and epithelial cells from human thymus

In this protocol we provide a method to isolate dendritic cells (DC) and epithelial cells (TEC) from the human thymus. DC and TEC are the major antigen presenting cell (APC) types found in a normal thymus and it is well established that they play distinct roles during thymic selection. These cells are localized in distinct microenvironments in the thymus and each APC type makes up only a minor population of cells. To further understand the biology of these cell types, characterization of these cell populations is highly desirable but due to their low frequency, isolation of any of these cell types requires an efficient and reproducible procedure. This protocol details a method to obtain cells suitable for characterization of diverse cellular properties. Thymic tissue is mechanically disrupted and after different steps of enzymatic digestion, the resulting cell suspension is enriched using a Percoll density centrifugation step. For isolation of myeloid DC (CD11c+), cells from the low-density fraction (LDF) are immunoselected by magnetic cell sorting. Enrichment of TEC populations (mTEC, cTEC) is achieved by depletion of hematopoietic (CD45hi) cells from the low-density Percoll cell fraction allowing their subsequent isolation via fluorescence activated cell sorting (FACS) using specific cell markers. The isolated cells can be used for different downstream applications.

As starting material in this protocol we use thymus tissue removed from children undergoing corrective cardiovascular surgery (Department of Thoracic and Cardiovascular Surgery, University Clinic Tuebingen) obtained after informed consent and under institutional guidelines. This discarded material can vary greatly in size from 2-30 g or more. The number of mDC and TEC subsets (cTEC and mTEC) that are obtained depends on the size as well as the age of the thymus tissue sample used for isolation.
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Watch this Scientific Journal Video about Isolation of Myeloid Dendritic Cells and Epithelial Cells from Human Thymus at JoVE.com

Isolation of Myeloid Dendritic Cells and Epithelial Cells from Human Thymus

This protocol details a method to isolate antigen presenting cells from human thymus via different steps of enzymatic digestion of the tissue followed by density centrifugation of the single cell suspension and finally magnetic and/or FACS sorting of the cell populations of interest.

In this protocol we provide a method to isolate dendritic cells (DC) and epithelial cells (TEC) from the human thymus. DC and TEC are the major antigen ...

isolation-myeloid-dendritic-cells-epithelial-cells-from-human

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Immunology and Infection

19.1K Views.  Hertie Institute for Clinical Brain Research. This protocol details a method to isolate antigen presenting cells from human thymus via different steps of enzymatic digestion of the tissue followed by density centrifugation of the single cell suspension and finally magnetic and/or FACS sorting of the cell populations of interest.

Video: Isolation of Myeloid Dendritic Cells and Epithelial Cells from Human Thymus

Isolation of Mouse Lung Dendritic Cells

Lung dendritic cells (DC) play a fundamental role in sensing invading pathogens 1,2 as well as in the control of tolerogenic responses 3 in the respiratory tract. At least three main subsets of lung dendritic cells have been described in mice: conventional DC (cDC) 4, plasmacytoid DC (pDC) 5 and the IFN-producing killer DC (IKDC) 6,7. The cDC subset is the most prominent DC subset in the lung 8. 
The common marker known to identify DC subsets is CD11c, a type I transmembrane integrin (&beta;2) that is also expressed on monocytes, macrophages, neutrophils and some B cells 9. In some tissues, using CD11c as a marker to identify mouse DC is valid, as in spleen, where most CD11c+ cells represent the cDC subset which expresses high levels of the major histocompatibility complex class II (MHC-II). However, the lung is a more heterogeneous tissue where beside DC subsets, there is a high percentage of a distinct cell population that expresses high levels of CD11c bout low levels of MHC-II. Based on its characterization and mostly on its expression of F4&#47;80, an splenic macrophage marker, the CD11chiMHC-IIlo lung cell population has been identified as pulmonary macrophages 10 and more recently, as a potential DC precursor 11. 
In contrast to mouse pDC, the study of the specific role of cDC in the pulmonary immune response has been limited due to the lack of a specific marker that could help in the isolation of these cells. Therefore, in this work, we describe a procedure to isolate highly purified mouse lung cDC. The isolation of pulmonary DC subsets represents a very useful tool to gain insights into the function of these cells in response to respiratory pathogens as well as environmental factors that can trigger the host immune response in the lung.

A highly purified preparation of mouse lung dendritic cells is described. Specific emphasis is given to the isolation of conventional dendritic cell subset.

Lung dendritic cells (DC) play a fundamental role in sensing invading pathogens 1,2 as well as in the control of tolerogenic responses 3 in the ...

Isolation and Characterization of Dendritic Cells and Macrophages from the Mouse Intestine

Within the intestine reside unique populations of innate and adaptive immune cells that are involved in promoting tolerance towards commensal flora and food antigens while concomitantly remaining poised to mount inflammatory responses toward invasive pathogens1,2. Antigen presenting cells, particularly DCs and macrophages, play critical roles in maintaining intestinal immune homeostasis via their ability to sense and appropriately respond to the microbiota3-14. Efficient isolation of intestinal DCs and macrophages is a critical step in characterizing the phenotype and function of these cells. While many effective methods of isolating intestinal immune cells, including DCs and macrophages, have been described6,10,15-24, many rely upon long digestions times that may negatively influence cell surface antigen expression, cell viability, and/or cell yield. Here, we detail a methodology for the rapid isolation of large numbers of viable, intestinal DCs and macrophages. Phenotypic characterization of intestinal DCs and macrophages is carried out by directly staining isolated intestinal cells with specific fluorescence-labeled monoclonal antibodies for multi-color flow cytometric analysis. Furthermore, highly pure DC and macrophage populations are isolated for functional studies utilizing CD11c and CD11b magnetic-activated cell sorting beads followed by cell sorting.

Here, we detail a methodology for the rapid isolation of mouse intestinal dendritic cells (DCs) and macrophages. Phenotypic characterization of intestinal DCs and macrophages is performed using multi-color flow cytometric analysis while magnetic bead enrichment followed by cell sorting is used to yield highly pure populations for functional studies.

Within the intestine reside unique populations of innate and adaptive immune cells that are involved in promoting tolerance towards commensal flora and ...

Isolating And Immunostaining Lymphocytes and Dendritic Cells from Murine Peyer's Patches

Peyer's patches (PPs) are integral components of the gut-associated lymphoid tissues (GALT) and play a central role in intestinal immunosurveillance and homeostasis. Particulate antigens and microbes in the intestinal lumen are continuously sampled by PP M cells in the follicle-associated epithelium (FAE) and transported to an underlying network of dendritic cells (DCs), macrophages, and lymphocytes. In this article, we describe protocols in which murine PPs are (i) dissociated into single cell suspensions and subjected to flow cytometry and (ii) prepared for cryosectioning and immunostaining. For flow cytometry, PPs are mechanically dissociated and then filtered through 70 &mu;m membranes to generate single cell suspensions free of epithelial cells and large debris. Starting with 20-25 PPs (from four mice), this quick and reproducible method yields a population of &gt;2.5 x 106 cells with &gt;90% cell viability. For cryosectioning, freshly isolated PPs are immersed in Optimal Cutting Temperature (OCT) medium, snap-frozen in liquid nitrogen, and then sectioned using a cryomicrotome. Tissue sections (5-12 &mu;m) are air-dried, fixed with acetone or methanol, and then subjected to immunolabeling.

Isolating And Immunostaining Lymphocytes and Dendritic Cells from Murine Peyer&#039;s Patches

There is an increasing interest in understanding the immunological functions of specific subpopulations of cells in Peyer's patches (PPs), the primary inductive sites of gut-associated lymphoid tissues. Here we outline parallel protocols for preparing PP single cell preparations for flow cytometric analysis and PP cryosections for immunostaining.

Peyer's  patches (PPs) are integral components of the gut-associated lymphoid tissues  (GALT) and play a central role in intestinal immunosurveillance and ...

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.

HIV-1 innate sensing requires direct contact of infected CD4+ T cells with plasmacytoid dendritic cells (pDCs). In order to study this process, the protocols described here use freshly isolated human peripheral blood mononuclear cells (PBMCs) or plasmacytoid dendritic cells (pDCs) to sense infections in either T cell line (MT4) or heterologous primary CD4+ T cells. In order to ensure proper sensing, it is essential that PBMC are isolated immediately after blood collection and that optimal percentage of infected T cells are used. Furthermore, multi-parametric flow cytometric staining can be used to confirm that PBMC samples contain the different cell lineages at physiological ratios. A number of controls can also be included to evaluate viability and functionality of pDCs. These include, the presence of specific surface markers, assessing cellular responses to known agonist of Toll-Like Receptors (TLR) pathways, and confirming a lack of spontaneous type-I interferon (IFN) production. In this system, freshly isolated PBMCs or pDCs are co-cultured with HIV-1 infected cells in 96 well plates for 18-22 hr. Supernatants from these co-cultures are then used to determine the levels of bioactive type-I IFNs by monitoring the activation of the ISGF3 pathway in HEK-Blue IFN-&#945;/&#946; cells. Prior and during co-culture conditions, target cells can be subjected to flow cytometric analysis to determine a number of parameters, including the percentage of infected cells, levels of specific surface markers, and differential killing of infected cells. Although, these protocols were initially developed to follow type-I IFN production, they could potentially be used to study other imuno-modulatory molecules released from pDCs and to gain further insight into the molecular mechanisms governing HIV-1 innate sensing.

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.

Unlike cell-free HIV-1 particles, infected CD4+ T cells are effectively sensed by plasmacytoid dendritic cells (pDCs). This manuscript describes a method where peripheral blood mononuclear cells (PBMCs) or isolated pDCs are co-cultured with HIV-1 infected T cells to evaluate innate sensing by pDCs as assessed by release of type-I IFN.

HIV-1 innate sensing requires direct contact of infected CD4+ T cells with plasmacytoid dendritic cells (pDCs). In order to study this process, the ...

Isolation, Identification, and Purification of Murine Thymic Epithelial Cells

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple stages of T cell development: T cell commitment, positive selection and negative selection. However, the function of TECs in the thymus remains incompletely understood. In the article, we provide a method to isolate TEC subsets from fresh mouse thymus using a combination of mechanical disruption and enzymatic digestion. The method allows thymic stromal cells and thymocytes to be efficiently released from cell-cell and cell-extracellular matrix connections and to form a single-cell suspension. Using the isolated cells, multiparameter flow cytometry can be applied to identification and characterization of TECs and dendritic cells. Because TECs are a rare cell population in the thymus, we also describe an effective way to enrich and purify TECs by depleting thymocytes, the most abundant cell type in the thymus. Following the enrichment, cell sorting time can be decreased so that loss of cell viability can be minimized during purification of TECs. Purified cells are suitable for various downstream analyses like Real Time-PCR, Western blot and gene expression profiling. The protocol will promote research of TEC function and as well as the development of in vitro T cell reconstitution.

Here we describe an efficient method for isolation, identification, and purification of mouse thymic epithelial cells (TECs). The protocol can be utilized for studies of thymus function for normal T cell development, thymus dysfunction, and T cell reconstitution.

The thymus is a vital organ for T lymphocyte development. Of thymic stromal cells, thymic epithelial cells (TECs) are particularly crucial at multiple ...

T Cells Capture Bacteria by Transinfection from Dendritic Cells

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic cells (DCs) by a process called transinfection. Here, we describe the analysis of the transinfection process, which occurs during the course of antigen presentation. This process was unveiled by using CD4+ T cells from transgenic OTII mice, which bear a T cell receptor (TCR) specific for a peptide of ovoalbumin (OVAp), which therefore can form stable immune complexes with infected dendritic cells loaded with this specific OVAp. The dynamics of green fluorescent protein (GFP)-expressing bacteria during DC-T cell transmission can be monitored by live-cell imaging and the quantification of bacterial transinfection can be performed by flow cytometry. In addition, transinfection can be quantified by a more sensitive method based in the use of gentamicin, a non-permeable aminoglycoside antibiotic killing extracellular bacteria but not intracellular ones. This classical method has been used previously in microbiology to study the efficiency of bacterial infections. We hereby explain the protocol of the complete process, from the isolation of the primary cells to the quantification of transinfection.

Here a protocol is presented to measure bacterial capture by CD4+ T cells which occurs during antigen presentation via transinfection from pre-infected dendritic cells (DC). We show how to perform the necessary steps: isolation of primary cells, infection of DC, DC/T cell conjugate formation, and measurement of bacterial T cell transfection.

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic ...

Generation of Human Monocyte-derived Dendritic Cells from Whole Blood

Dendritic cells (DCs) recognize foreign structures of different pathogens, such as viruses, bacteria, and fungi, via a variety of pattern recognition receptors (PRRs) expressed on their cell surface and thereby activate and regulate immunity. 
The major function of DCs is the induction of adaptive immunity in the lymph nodes by presenting antigens via MHC I and MHC II molecules to na&#239;ve T lymphocytes. Therefore, DCs have to migrate from the periphery to the lymph nodes after the recognition of pathogens at the sites of infection. For in vitro experiments or DC vaccination strategies, monocyte-derived DCs are routinely used. These cells show similarities in physiology, morphology, and function to conventional myeloid dendritic cells. They are generated by interleukin 4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation of monocytes isolated from healthy donors. Here, we demonstrate how monocytes are isolated and stimulated from anti-coagulated human blood after peripheral blood mononuclear cell (PBMC) enrichment by density gradient centrifugation. Human monocytes are differentiated into immature DCs and are ready for experimental procedures in a non-clinical setting after 5 days of incubation.

Here, we demonstrate how monocytes are isolated by magnetic bead separation from peripheral blood mononuclear cells after density gradient centrifugation of human anti-coagulated blood. Following incubation for 5 days, human monocytes are differentiated into immature dendritic cells and are ready for experimental procedures in a non-clinical setting.

Dendritic cells (DCs) recognize foreign structures of different pathogens, such as viruses, bacteria, and fungi, via a variety of pattern recognition ...

Isolation of Dendritic Cells from the Human Female Reproductive Tract for Phenotypical and Functional Studies

The characterization of the human dendritic cells (DCs) resident in mucosal tissues is challenging due to the difficulty in obtaining samples, and the low numbers of DCs present per tissue. Yet, as the phenotype and function of DCs is modified by the tissue environment, it is necessary to analyze tissue resident DC populations, since blood derived DCs incompletely reflect the complexities of DCs in tissues. Here we present a protocol to isolate DCs from the human female reproductive tract (FRT) using hysterectomy specimens that allows both phenotypical and functional analyses. The protocol consists of tissue digestion to generate a single cell mixed cell suspension, followed by positive magnetic bead selection. Our tissue digestion protocol does not cleave surface markers, which allows phenotypical and functional analysis of DCs in the steady state, without overnight incubation or cell activation. This protocol can be adapted for the isolation of other immune cell types or isolation of DCs from other tissues.

We describe here a method to isolate and purify dendritic cells from different anatomical compartments in the human female reproductive tract for the evaluation of their phenotypical and functional characteristics. This method can be adapted to isolate other immune cells or dendritic cells from other mucosal tissues.

The characterization of the human dendritic cells (DCs) resident in mucosal tissues is challenging due to the difficulty in obtaining samples, and the low ...

Development and Validation of an Ultrasensitive Single Molecule Array Digital Enzyme-linked Immunosorbent Assay for Human Interferon-&#945;

The main aim of this protocol is to describe the development and validation of an interferon (IFN)-&#945; single molecule array digital Enzyme-Linked ImmunoSorbent Assay (ELISA) assay. This system enables the quantification of human IFN-&#945; protein with unprecedented sensitivity, and with no cross-reactivity for other species of IFN.
The first key step of the protocol is the choice of the antibody pair, followed by the conjugation of the capture antibody to paramagnetic beads, and biotinylation of the detection antibody. Following this step, different parameters such as assay configuration, detector antibody concentration, and buffer composition can be modified until optimum sensitivity is achieved. Finally, specificity and reproducibility of the method are assessed to ensure confidence in the results. Here, we developed an IFN-&#945; single molecule array assay with a limit of detection of 0.69 fg/mL using high-affinity autoantibodies isolated from patients with biallelic mutations in the autoimmune regulator (AIRE) protein causing autoimmune polyendocrinopathy syndrome type 1/autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APS1/APECED). Importantly, these antibodies enabled detection of all 13 IFN-&#945; subtypes.
This new methodology allows the detection and quantification of IFN-&#945; protein in human biological samples at attomolar concentrations for the first time. Such a tool will be highly useful in monitoring the levels of this cytokine in human health and disease states, most particularly infection, autoimmunity, and autoinflammation.

Development and Validation of an Ultrasensitive Single Molecule Array Digital Enzyme-linked Immunosorbent Assay for Human Interferon-&amp;#945;

Here we present a protocol to describe the development and validation of a single molecule array digital ELISA assay, which enables the ultra-sensitive detection of all IFN-&#945; subtypes in human samples.

The main aim of this protocol is to describe the development and validation of an interferon (IFN)-&#945; single molecule array digital Enzyme-Linked ...

Isolation and Adoptive Transfer of High Salt Treated Antigen-presenting Dendritic Cells

Excess dietary salt intake contributes to inflammation and plays a vital role in the development of hypertension. We previously found that antigen-presenting dendritic cells (DCs) can sense elevated extracellular sodium leading to the activation of the NADPH oxidase and formation of isolevuglandin (IsoLG)-protein adducts. These IsoLG-protein adducts react with self-proteins and promote an autoimmune-like state and hypertension. We have developed and optimized state-of-the-art methods to study DC function in hypertension. Here, we provide a detailed protocol for isolation, in vitro treatment with elevated sodium, and adoptive transfer of murine splenic CD11c+ cells into recipient mice to study their role in hypertension.

Here, we present a protocol to isolate dendritic cells from murine spleens by magnetic cell sorting and subsequent adoptive transfer into na&#239;ve mice. The model of high-salt activated dendritic cells was chosen to explain the step-by-step procedures of adoptive transfer and flow cytometry.