We thank the Miami WIHS study participants for their willingness to participate in this work. Data in this manuscript were collected by the Miami Women&#39;s Interagency HIV Study (WIHS). The contents of this publication are solely the responsibility of the authors and do not represent the official views of the National Institutes of Health (NIH). This work was supported by National Institute of Allergy and Infectious Diseases and Women&#39;s Interagency HIV Infection Study (WIHS) [grant number U01 AI103397], National Institute of Allergy and Infectious Diseases, National Institutes of Health [ grant number P30AI073961], National Center for Advancing Translational Sciences and the National Institute on Minority Health and Health Disparities, National Institute of Health [grant number UL1TR000460 and 1KL2TR000461], and National Institute of Child Health and Human Development, National Institute of Health [ grant number K23HD074489].

Study activities took place at University of Miami HIV Research Unit in collaboration with the Miami Women&#39;s HIV Interagency Study (WIHS) and the Miami Center for AIDS Research (CFAR).Institutional Review Board (University of Miami Miller School of Medicine) approval was obtained prior to recruitment and any assessment or study related procedures.
1. Endocervical Brush Sample Collection
NOTE: Participants underwent a vaginal examination performed by trained MD or gynecologist and collection of intraepithelial lymphocytes were performed under speculum examination by inserting cytobrush.
<ol>
	<li>Participant characteristics
	<ol>
		<li>Recruit women participants who are aged 18 to 45 years of age, sexually active, not pregnant and not on contraceptive medications or with an intrauterine device.</li>
		<li>Before vaginal examination, have participants undergo a 10 mL blood draw in green top heparin vacutainers for peripheral blood mononuclear cell (PBMC) isolation. to serve as a control for endocervical intraepithelial analysis9.</li>
	</ol>
	</li>
	<li>Collection of the endocervical samples
	<ol>
		<li>Insert a sterile speculum of appropriate size into the vagina without lubrication. Use a warm water to facilitate insertion of the speculum and sterile gauze to clean the mucus. The position of the speculum allows for complete visualization of the os and ectocervix.</li>
		<li>Insert endocervical brush into the endocervical canal until only the bristles closest to the hand are visible. Rotate the brush clockwise for 360&#176;. Transfer the brush into a 15 mL tube containing 5 ml of IMDM medium.</li>
		<li>Immediately after collection, place the tube containing cytobrush on ice. To obtain high viability of collected intraepithelial cells, deliver the cytobrush to the lab and process within 1 h.</li>
	</ol>
	</li>
</ol>
2. Endocervical Cytobrush Sample Processing
<ol>
	<li>Vortex tube containing&#160;endocervical cytobrush applying 4 short (10 sec) strokes.</li>
	<li>Centrifuge the tube, containing cytobrush, for 10 min at 250 x g.</li>
	<li>Carefully remove the cytobrush from the tube (do not disturb the pellet on the bottom of the tube) and add 1 mL of IMDM media and place the tube on ice.</li>
	<li>Place the cytobrush on the 100 mm cell strainer on top of the 50 ml tube.</li>
	<li>Wash the cytobrush with 20 ml IMDM.</li>
	<li>Centrifuge tube for 10 min at 250 x g.</li>
	<li>Decant the supernatant and pelleted cells resuspend in 1 mL IMDM and combine with the already re-suspended pellet described in 2.3.</li>
	<li>Count the cells using an automated cell counter10 or count the cells using hemocytometer by combining 10 &#181;L of the cell suspension with 10 &#181;L of trypan blue dye. Gently pipet up and down ten times to mix the cells and dye. Load 10 &#181;L of the mixture into the opening of either of the two hemocytometer chambers. Count all the cells in the five grid areas. Keep a separate count of the viable and non-viable cells. Determine the cell viability using the following formula: % Viable cells = Non-viable cells x 100/total cell number cells. 
	Determine the subsequent cell concentration per ml (and the total number of cells) using the following calculations. Total Cells per ml = total cells counted x (dilution factor/ number of counted square) x 10,000 cells/ml.</li>
	<li>Freeze isolated endocervical cells using freezing medium containing 10% DMSO and 90% FBS.</li>
</ol>
3. Flow Cytometry
<ol>
	<li>Re-suspend 1-3 x 105 endocervical cells in 100 &#956;L FACS buffer (PBS containing 1% bovine serum albumin</li>
	<li>Add 1 &#956;L/106 LIVE/DEAD Fixable Yellow Dead Cell Stain kit and antibodies for surface markers at the concentrations described in Table 1.</li>
	<li>Incubate the cells for 30 min at +4 &#176;C , protected from light.</li>
	<li>Add 1 mL FACS buffer and the cells and centrifuge tubes for 5 min at 350 x g</li>
	<li>Re-suspend cell pellet in 300 &#956;L 1% paraformaldehyde.</li>
	<li>Prepare compensation controls using beads and antibodies used for staining by adding 100 &#956;L of FACS buffer and one drop of the beads and the same concentration of the antibodies used for sample staining.</li>
	<li>Acquire stained beads and samples on a flow cytometer, equipped with 405 nm, 488 nm, and 635 nm lasers.</li>
</ol>
4. Endocervical Gamma delta T Cell Isolation
<ol>
	<li>Magnetic bead isolation
	<ol>
		<li>Re-suspend endocervical cell pellet (&#8804;107 total cells), described in 2.6, in 40 &#181;L of buffer included in the TCR gamma delta microbead kit referenced in the Table of Materials and Reagents.</li>
		<li>Follow the kit instructions for two-step staining protocol: first, with anti-TCR gamma delta Hapten-Antibody and second, with anti-hapten microbeads-FITC</li>
		<li>After incubation of 15 min at 4-8 &#176;C, wash the cells by adding 1 mL of buffer and centrifuge at 300 x g for 10 min.&#160;Decant the supernatant by inverting the tube, and tap dry with the help of a piece of paper.</li>
		<li>Re-suspend the cell pellet in 500 &#956;L of provided buffer and prepare the magnetic column by placing it in appropriate magnetic separator according to the vendor&#39;s protocol.</li>
		<li>Apply cell suspension onto the column and collect unlabeled cells which pass through and wash column 3x with appropriate amount of buffer (500 &#181;L). Perform washing steps by adding buffer three times, each time once the column reservoir is empty. Collect total effluent. This is the unlabeled, negative cell fraction</li>
		<li>Remove the column form the magnetic separator and pipette 1 ml of buffer onto the column and immediately flush out fraction with the magnetically labeled cells by firmly applying the plunger supplied with the column. 
		NOTE: Isolated gamma delta T cell are already fluorescently stained for flow-cytometric analysis since magnetically labeled Anti-Hapten microbeads are conjugated with fluorescent dye FITC.</li>
	</ol>
	</li>
	<li>Cell sorting
	<ol>
		<li>For cell sorting, label endocervical cells with viability die and antibody panel as described in section 3.</li>
		<li>Set up electronic gates on the live, CD45+ CD3+ and gamma delta positive cells and perform cell sorting.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Kaul, R., 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=The+genital+tract+immune+milieu:+an+important+determinant+of+HIV+susceptibility+and+secondary+transmission.">The genital tract immune milieu: an important determinant of HIV susceptibility and secondary transmission.</a> J Reprod Immunol. 77, 32-40 (2008).</li><li>Haase, A. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeting+early+infection+to+prevent+HIV-1+mucosal+transmission.">Targeting early infection to prevent HIV-1 mucosal transmission.</a> Nature. 464, 217-223 (2010).</li><li>Hayday, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=gamma][delta]+cells:+a+right+time+and+a+right+place+for+a+conserved+third+way+of+protection.">gamma][delta] cells: a right time and a right place for a conserved third way of protection.</a> Ann Rev Immunol. 18, 975-1026 (2000).</li><li>Nakasone, 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=Accumulation+of+gamma/delta+T+cells+in+the+lungs+and+their+roles+in+neutrophil-mediated+host+defense+against+pneumococcal+infection.">Accumulation of gamma/delta T cells in the lungs and their roles in neutrophil-mediated host defense against pneumococcal infection.</a> Microbes and infection / Institut Pasteur. 9, 251-258 (2007).</li><li>Autran, 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=T+cell+receptor+gamma/delta++lymphocyte+subsets+during+HIV+infection.">T cell receptor gamma/delta+ lymphocyte subsets during HIV infection.</a> Clin Exp Immunol. 75, 206-210 (1989).</li><li>Pauza, C. D., Poonia, B., Li, H., Cairo, C., Chaudhry, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=gammadelta+T+Cells+in+HIV+Disease:+Past,+Present,+and+Future.">gammadelta T Cells in HIV Disease: Past, Present, and Future.</a> Front Immunol. 5, 687 (2014).</li><li>Hayday, A. C., Spencer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Barrier+immunity.">Barrier immunity.</a> Sem Immunol. 21, 99-100 (2009).</li><li>Cheroutre, H., Lambolez, F., Mucida, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+light+and+dark+sides+of+intestinal+intraepithelial+lymphocytes.">The light and dark sides of intestinal intraepithelial lymphocytes.</a> Nature Rev Immunol. 11, 445-456 (2011).</li><li>Strbo, 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=Loss+of+Intra-Epithelial+Endocervical+Gamma+Delta+(GD)+1+T+Cells+in+HIV-Infected+Women.">Loss of Intra-Epithelial Endocervical Gamma Delta (GD) 1 T Cells in HIV-Infected Women.</a> AJRI. 75, 134-145 (2016).</li><li>Szabo, S. E., Monroe, S. L., Fiorino, S., Bitzan, J., Loper, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+an+automated+instrument+for+viability+and+concentration+measurements+of+cryopreserved+hematopoietic+cells.">Evaluation of an automated instrument for viability and concentration measurements of cryopreserved hematopoietic cells.</a> Lab Hematol. 10, 109-111 (2004).</li><li>Alcaide, M. 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=Bacterial+Vaginosis+Is+Associated+with+Loss+of+Gamma+Delta+T+Cells+in+the+Female+Reproductive+Tract+in+Women+in+the+Miami+Women+Interagency+HIV+Study+(WIHS):+A+Cross+Sectional+Study.">Bacterial Vaginosis Is Associated with Loss of Gamma Delta T Cells in the Female Reproductive Tract in Women in the Miami Women Interagency HIV Study (WIHS): A Cross Sectional Study.</a> PloS one. 11, e0153045 (2016).</li><li>Masson, 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=Defining+genital+tract+cytokine+signatures+of+sexually+transmitted+infections+and+bacterial+vaginosis+in+women+at+high+risk+of+HIV+infection:+a+cross-sectional+study.">Defining genital tract cytokine signatures of sexually transmitted infections and bacterial vaginosis in women at high risk of HIV infection: a cross-sectional study.</a> Sex Transm Dis. 90, 580-587 (2014).</li><li>Fichorova, R. 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=Interleukin+(IL)-1,+IL-6,+and+IL-8+predict+mucosal+toxicity+of+vaginal+microbicidal+contraceptives.">Interleukin (IL)-1, IL-6, and IL-8 predict mucosal toxicity of vaginal microbicidal contraceptives.</a> Biol Reprod. 71, 761-769 (2004).</li><li>Juno, J. A., Boily-Larouche, G., Lajoie, J., Fowke, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collection,+isolation,+and+flow+cytometric+analysis+of+human+endocervical+samples.">Collection, isolation, and flow cytometric analysis of human endocervical samples.</a> JoVE. , (2014).</li><li>McKinnon, L. R., 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=Optimizing+viable+leukocyte+sampling+from+the+female+genital+tract+for+clinical+trials:+an+international+multi-site+study.">Optimizing viable leukocyte sampling from the female genital tract for clinical trials: an international multi-site study.</a> PloS one. 9, e85675 (2014).</li><li>Dominguez, M. 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=Highly+multiplexed+quantitation+of+gene+expression+on+single+cells.">Highly multiplexed quantitation of gene expression on single cells.</a> J Immunol Methods. 391, 133-145 (2013).</li></ol>

Authors do not have commercial or other association that might pose a conflict of interest (e.g., pharmaceutical stock ownership, consultancy, advisory board membership, relevant patents, or research funding).

Assessment of female lower genital tract mucosal vulnerability is an essential component of clinical studies addressing risk of HIV acquisition and transmission. Typically FGT vulnerability to HIV infection is evaluated by measuring soluble immune modulators in genital secretions (cytokines, chemokines and antimicrobial peptides)12,13. However, these biomarkers are only indicative of vaginal inflammation, are affected by physiological and pathological events, and...

We developed methodology of using endocervical brush samples to evaluate intraepithelial GD T cells. The endocervical canal is lined by a single layer of columnar epithelium. Intraepithelial lymphocytes represent frontline lymphocytes residing within the epithelial layer that can rapidly initiate immune responses upon encountering pathogenic microbes7,8. Understanding the immunological events of endocervical intraepithelial compartment is important for the design of effective strategies to prevent infections, including HIV.
Our method can be applied for freshly collected human endocervical samples as well as frozen endocervical cells to further explore the role of intraepithelial GD T cells in women with HIV infection or at risk for HIV infection. The main goal of this protocol is to discover novel immunological events in endocervical intraepithelial compartment and to evaluate GD T cell responses as a marker of mucosal vulnerability in women with HIV infection.
The substantial gaps in knowledge around FGT immunity are partially due to the difficulty in successfully collecting and processing mucosal samples. Furthermore, the complex heterogeneity of mucosal immune cells, and their interconnectedness with each other, are major challenges to identifying clinically relevant measurements that reflect the state and capability of the immune system. We developed a method to obtain highly purified intraepithelial GD T cells that can be further analyzed using highly multiplexed, single-cell technologies that may be critical for identifying the underlying mechanisms of FRT immunity.

<table border="0" cellpadding="0" cellspacing="0" width="648">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Cytobrush Plus GT&#160;</td>
			<td style="width:147px;">(CareFusion, San Diego, CA, USA</td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">IMDM,Iscove&#39;s Modified Dulbecco&#39;s Medium&#160;</td>
			<td style="width:147px;">ThermoFisher Scientific</td>
			<td align="right" style="width:119px;">12440061</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Beckman Coulter automated cell counter (The Vi-CELL Series Cell Viability Analyzer</td>
			<td style="width:147px;">Beckman Coulter</td>
			<td align="right" style="width:119px;">496178</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">DMSO, Dimethyl sulfoxide&#160;</td>
			<td style="width:147px;">Sigma Aldrich&#160;</td>
			<td style="width:119px;">D2650</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">FBS, Fetal Bovine Serum</td>
			<td style="width:147px;">Invitrogen, Gibco</td>
			<td style="width:119px;">26140-079</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PBS</td>
			<td style="width:147px;">Invitrogen, Gibco</td>
			<td align="right" style="width:119px;">10010023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">BSA</td>
			<td style="width:147px;">Sigma Aldrich</td>
			<td style="width:119px;">A-9647</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">LIVE/DEAD Fixable Yellow Dead Cell Stain kit&#160;</td>
			<td style="width:147px;">Life Technologies,</td>
			<td style="width:119px;">L349S9</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">1% paraformaldehyde (Sigma-Aldrich</td>
			<td style="width:147px;">Sigma Aldrich&#160;</td>
			<td style="width:119px;">D6148</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Fortessa flow cytometer&#160;</td>
			<td style="width:147px;">Becton Dickinson</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">UltraComp eBeads</td>
			<td style="width:147px;">eBioscience</td>
			<td style="width:119px;">01-2222-42</td>
			<td></td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">ArC Amine Reactive Compensation Beads (Life Technologies, Grand Island, NY, USA)</td>
			<td style="width:147px;">Life Technologies</td>
			<td style="width:119px;">A10346</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">anti-TCR gamma/delta MicroBead Kit&#160;</td>
			<td style="width:147px;">Milteny Miltenyi Biotec Inc.</td>
			<td style="width:119px;">130-050-701</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">MS column</td>
			<td style="width:147px;"></td>
			<td style="width:119px;">103-042-201</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">MACS separator</td>
			<td style="width:147px;"></td>
			<td align="right" style="width:119px;">4124</td>
			<td></td>
		</tr>
	</tbody>
</table>

isolation and flow cytometric analysis of human endocervical gamma delta t cells

The female reproductive tract (FRT) mucosal immune system serves as the first line of defense. Better knowledge of the genital mucosa is therefore essential for understanding pathogenicity of different pathogens including HIV. Gamma delta (GD) T cells are the prototype of &#39;unconventional&#39; T cells and represent a relatively small subset of T cells defined by their expression of heterodimeric T-cell receptors (TCRs) composed of gamma and delta chains. This sets them apart from the classical and much better known CD4+ helper T cells and CD8+ cytotoxic T cells that are defined by alpha-beta TCRs. GD T cells often show tissue-specific localization and are enriched in epithelium. GD T cells orchestrate immune responses in inflammation, tumor surveillance, infectious disease, and autoimmunity.
Here, we present a method to reproducibly isolate and analyze human endocervical intraepithelial GD T lymphocytes. We have used endocervical cytobrush samples from women participating in the Women&#39;s Interagency HIV Infection Study (WIHS). Knowledge about GD T cells interactions during conditions in which there is an insult to the vaginal mucosal could be applied to any clinical study in which mucosal vulnerability is addressed, including the development of vaginal microbicides.In addition, knowledge about mucosal GD T cell responses has potential for application of GD T cell-based immune therapy in treating infectious diseases.

Recently, we analyzed endocervical intraepithelial GD T cells and we were the first one to report about the loss of endocervical gamma delta T cells in HIV infected women9,11. Here, we describe the protocol to isolate and analyze the subset of endocervical gamma delta T cells. As shown in Figure 1, GD T cells can be readily detected in the human endocervical cell samples.
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Watch this Scientific Journal Video about Isolation and Flow Cytometric Analysis of Human Endocervical Gamma Delta T Cells at JoVE.com

Isolation and Flow Cytometric Analysis of Human Endocervical Gamma Delta T Cells

We describe here an isolation method to obtain human endocervical intraepithelial lymphocytes for the analysis of intraepithelial gamma delta T cells. This protocol can be extended for the purification of endocervical gamma delta T cells by magnetic beads or by cell sorting.

The female reproductive tract (FRT) mucosal immune system serves as the first line of defense. Better knowledge of the genital mucosa is therefore ...

isolation-flow-cytometric-analysis-human-endocervical-gamma-delta-t

Research

JoVE Journal

Immunology and Infection

8.7K Views.  Miller School of Medicine, University of Miami. We describe here an isolation method to obtain human endocervical intraepithelial lymphocytes for the analysis of intraepithelial gamma delta T cells. This protocol can be extended for the purification of endocervical gamma delta T cells by magnetic beads or by cell sorting.

Video: Isolation and Flow Cytometric Analysis of Human Endocervical Gamma Delta T Cells

Human T Lymphocyte Isolation, Culture and Analysis of Migration In Vitro

The migration of T lymphocytes involves the adhesive interaction of cell surface integrins with ligands expressed on other cells or with extracellular matrix proteins. The precise spatiotemporal activation of integrins from a low affinity state to a high affinity state at the cell leading edge is important for T lymphocyte migration 1. Likewise, retraction of the cell trailing edge, or uropod, is a necessary step in maintaining persistent integrin-dependent T lymphocyte motility 2. Many therapeutic approaches to autoimmune or inflammatory diseases target integrins as a means to inhibit the excessive recruitment and migration of leukocytes 3. To study the molecular events that regulate human T lymphocyte migration, we have utilized an in vitro system to analyze cell migration on a two-dimensional substrate that mimics the environment that a T lymphocyte encounters during recruitment from the vasculature. T lymphocytes are first isolated from human donors and are then stimulated and cultured for seven to ten days. During the assay, T lymphocytes are allowed to adhere and migrate on a substrate coated with intercellular adhesion molecule-1 (ICAM-1), a ligand for integrin LFA-1, and stromal cell-derived factor-1 (SDF-1). Our data show that T lymphocytes exhibit a migratory velocity of ~15 &mu;m/min. T lymphocyte migration can be inhibited by integrin blockade 1 or by inhibitors of the cellular actomyosin machinery that regulates cell migration 2.

Human T Lymphocyte Isolation, Culture and Analysis of Migration In Vitro

T lymphocyte migration occurs during homing to lymphoid organs, exit from the vasculature, and entering into peripheral tissues. Here, we describe a protocol that can be used to analyze T lymphocyte migration in vitro.

The migration of T lymphocytes involves the adhesive interaction of cell surface integrins with ligands expressed on other cells or with extracellular ...

Flow Cytometric Isolation of Primary Murine Type II Alveolar Epithelial Cells for Functional and Molecular Studies

Throughout the last years, the contribution of alveolar type II epithelial cells (AECII) to various aspects of immune regulation in the lung has been increasingly recognized. AECII have been shown to participate in cytokine production in inflamed airways and to even act as antigen-presenting cells in both infection and T-cell mediated autoimmunity 1-8. Therefore, they are especially interesting also in clinical contexts such as airway hyper-reactivity to foreign and self-antigens as well as infections that directly or indirectly target AECII. However, our understanding of the detailed immunologic functions served by alveolar type II epithelial cells in the healthy lung as well as in inflammation remains fragmentary. Many studies regarding AECII function are performed using mouse or human alveolar epithelial cell lines 9-12. Working with cell lines certainly offers a range of benefits, such as the availability of large numbers of cells for extensive analyses. However, we believe the use of primary murine AECII allows a better understanding of the role of this cell type in complex processes like infection or autoimmune inflammation. Primary murine AECII can be isolated directly from animals suffering from such respiratory conditions, meaning they have been subject to all additional extrinsic factors playing a role in the analyzed setting. As an example, viable AECII can be isolated from mice intranasally infected with influenza A virus, which primarily targets these cells for replication 13. Importantly, through ex vivo infection of AECII isolated from healthy mice, studies of the cellular responses mounted upon infection can be further extended.
Our protocol for the isolation of primary murine AECII is based on enzymatic digestion of the mouse lung followed by labeling of the resulting cell suspension with antibodies specific for CD11c, CD11b, F4/80, CD19, CD45 and CD16/CD32. Granular AECII are then identified as the unlabeled and sideward scatter high (SSChigh) cell population and are separated by fluorescence activated cell sorting 3.
In comparison to alternative methods of isolating primary epithelial cells from mouse lungs, our protocol for flow cytometric isolation of AECII by negative selection yields untouched, highly viable and pure AECII in relatively short time. Additionally, and in contrast to conventional methods of isolation by panning and depletion of lymphocytes via binding of antibody-coupled magnetic beads 14, 15, flow cytometric cell-sorting allows discrimination by means of cell size and granularity. Given that instrumentation for flow cytometric cell sorting is available, the described procedure can be applied at relatively low costs. Next to standard antibodies and enzymes for lung disintegration, no additional reagents such as magnetic beads are required. The isolated cells are suitable for a wide range of functional and molecular studies, which include in vitro culture and T-cell stimulation assays as well as transcriptome, proteome or secretome analyses 3, 4.

We describe the rapid isolation of primary murine type II alveolar epithelial cells (AECII) by flow cytometric negative selection. These AECII show high viability and purity and are suitable for a wide range of functional and molecular studies regarding their role in respiratory conditions such as autoimmune or infectious diseases.

Throughout  the last years, the contribution of alveolar type II epithelial cells (AECII)  to various aspects of immune regulation in the lung has been ...

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 and Flow Cytometric Analysis of Glioma-infiltrating Peripheral Blood Mononuclear Cells

Our laboratory has recently demonstrated that natural killer (NK) cells are capable of eradicating orthotopically implanted mouse GL26 and rat CNS-1 malignant gliomas soon after intracranial engraftment if the cancer cells are rendered deficient in their expression of the &#946;-galactoside-binding lectin galectin-1 (gal-1). More recent work now shows that a population of Gr-1+/CD11b+ myeloid cells is critical to this effect. To better understand the mechanisms by which NK and myeloid cells cooperate to confer gal-1-deficient tumor rejection we have developed a comprehensive protocol for the isolation and analysis of glioma-infiltrating peripheral blood mononuclear cells (PBMC). The method is demonstrated here by comparing PBMC infiltration into the tumor microenvironment of gal-1-expressing GL26 gliomas with those rendered gal-1-deficient via shRNA knockdown. The protocol begins with a description of&#160;how to culture and prepare GL26 cells for inoculation into the syngeneic C57BL/6J mouse brain. It then explains the steps involved in the isolation and flow cytometric analysis of glioma-infiltrating PBMCs from the early brain tumor microenvironment. The method is adaptable to a number of in vivo experimental designs in which temporal data on immune infiltration into the brain is required. The method is sensitive and highly reproducible, as glioma-infiltrating PBMCs can be isolated from intracranial tumors as soon as 24 hr post-tumor engraftment with similar cell counts observed from time point matched tumors throughout independent experiments. A single experimentalist can perform the method from brain harvesting to flow cytometric analysis of glioma-infiltrating PBMCs in roughly 4-6 hr depending on the number of samples to be analyzed. Alternative glioma models and/or cell-specific detection antibodies may also be used at the experimentalists&#8217; discretion to assess the infiltration of several other immune cell types of interest without the need for alterations to the overall procedure.

Presented here is a straightforward method for the isolation and flow cytometric analysis of glioma-infiltrating peripheral blood mononuclear cells that yields time-dependent quantitative data on the number and activation status of immune cells entering the early brain tumor microenvironment.

Our laboratory has recently demonstrated that natural killer (NK) cells are capable of eradicating orthotopically implanted mouse GL26 and rat CNS-1 ...

Isolation and Flow Cytometric Characterization of Murine Small Intestinal Lymphocytes

The intestines &#8212; which contain the largest number of immune cells of any organ in the body &#8212; are constantly exposed to foreign antigens, both microbial and dietary. Given an increasing understanding that these luminal antigens help shape the immune response and that education of immune cells within the intestine is critical for a number of systemic diseases, there has been increased interest in characterizing the intestinal immune system. However, many published protocols are arduous and time-consuming. We present here a simplified protocol for the isolation of lymphocytes from the small-intestinal lamina propria, intraepithelial layer, and Peyer&#39;s patches that is rapid, reproducible, and does not require laborious Percoll gradients. Although the protocol focuses on the small intestine, it is also suitable for analysis of the colon. Moreover, we highlight some aspects that may need additional optimization depending on the specific scientific question. This approach results in the isolation of large numbers of viable lymphocytes that can subsequently be used for flow cytometric analysis or alternate means of characterization.

There is growing interest in the quantitative characterization of intestinal lymphocytes owing to increasing recognition that these cells play a critical role in a variety of intestinal and systemic diseases. In this protocol, we describe how to isolate single cell populations from different small-intestinal compartments for subsequent flow cytometric characterization.

The intestines &#8212; which contain the largest number of immune cells of any organ in the body &#8212; are constantly exposed to foreign antigens, both ...

Flow Cytometric Analysis of Particle-bound Bet v 1 Allergen in PM10

Flow cytometry is a method widely used to quantify suspended solids such as cells or bacteria in a size range from 0.5 to several tens of micrometers in diameter. In addition to a characterization of forward and sideward scatter properties, it enables the use of fluorescent labeled markers like antibodies to detect respective structures. Using indirect antibody staining, flow cytometry is employed here to quantify birch pollen allergen (precisely Bet v 1)-loaded particles of 0.5 to 10 &#181;m in diameter in inhalable particulate matter (PM10, particle size &#8804;10 &#181;m in diameter). PM10 particles may act as carriers of adsorbed allergens possibly transporting them to the lower respiratory tract, where they could trigger allergic reactions.
So far the allergen content of PM10 has been studied by means of enzyme linked immunosorbent assays (ELISAs) and scanning electron microscopy. ELISA measures the dissolved and not the particle-bound allergen. Compared to scanning electron microscopy, which can visualize allergen-loaded particles, flow cytometry may additionally quantify them. As allergen content of ambient air can deviate from birch pollen count, allergic symptoms might perhaps correlate better with allergen exposure than with pollen count. In conjunction with clinical data, the presented method offers the opportunity to test in future experiments whether allergic reactions to birch pollen antigens are associated with the Bet v 1 allergen content of PM10 particles &#62;0.5 &#181;m.

Here, we present a protocol to quantify allergen-loaded particles by flow cytometry. Ambient particulate matter particles may act as carriers of adsorbed allergens. We show here that flow cytometry, a method widely used to characterize suspended solids &#62;0.5 &#181;m in diameter, can be used to measure these allergen-loaded particles.

Flow cytometry is a method widely used to quantify suspended solids such as cells or bacteria in a size range from 0.5 to several tens of micrometers in ...

Flow Cytometric Analysis of Natural Killer Cell Lytic Activity in Human Whole Blood

NK cell cytotoxicity is a widely used measure to determine the effect of outside intervention on NK cell function. However, the accuracy and reproducibility of this assay can be considered unstable, either because of user&#39;s errors or because of the sensitivity of NK cells to experimental manipulation. To eliminate these issues, a workflow that reduces them to a minimum was established and is presented here. To illustrate, we obtained blood samples, at various time points, from runners (n = 4) that were submitted to an intense bout of exercise. First, NK cells are simultaneously identified and isolated through CD56 tagging and magnetic-based sorting, directly from whole blood and from as little as one milliliter. The sorted NK cells are removed of any reagent or capping antibodies. They can be counted in order to establish an accurate NK cell count per milliliter of blood. Secondly, the sorted NK cells (effectors cells or E) can be mixed with 3,3&#39;-Diotadecyloxacarbocyanine Perchlorate (DiO) tagged K562 cells (target cells or T) at an assay-optimal 1:5 T:E ratio, and analyzed using an imaging flow-cytometer that allows for the visualization of each event and the elimination of any false positive or false negatives (such as doublets or effector cells). This workflow can be completed in about 4 h, and allows for very stable results even when working with human samples. When available, research teams can test several experimental interventions in human subjects, and compare measurements across several time points without compromising the data&#39;s integrity.

This work describes an advanced workflow for the accurate and fast determination of NK (Natural Killer) cell count and NK cell cytotoxicity in human blood samples.

NK cell cytotoxicity is a widely used measure to determine the effect of outside intervention on NK cell function. However, the accuracy and ...

Isolation and In Vitro Culture of Murine and Human Alveolar Macrophages

Alveolar macrophages are terminally differentiated, lung-resident macrophages of prenatal origin. Alveolar macrophages are unique in their long life and their important role in lung development and function, as well as their lung-localized responses to infection and inflammation. To date, no unified method for identification, isolation, and handling of alveolar macrophages from humans and mice exists. Such a method is needed for studies on these important innate immune cells in various experimental settings. The method described here, which can be easily adopted by any laboratory, is a simplified approach to harvesting alveolar macrophages from bronchoalveolar lavage fluid or from lung tissue and maintaining them in vitro. Because alveolar macrophages primarily occur as adherent cells in the alveoli, the focus of this method is on dislodging them prior to harvest and identification. The lung is a highly vascularized organ, and various cell types of myeloid and lymphoid origin inhabit, interact, and are influenced by the lung microenvironment. By using the set of surface markers described here, researchers can easily and unambiguously distinguish alveolar macrophages from other leukocytes, and purify them for downstream applications. The culture method developed herein supports both human and mouse alveolar macrophages for in vitro growth, and is compatible with cellular and molecular studies.

Isolation and In Vitro Culture of Murine and Human Alveolar Macrophages

This communication describes methodologies for isolation and culture of alveolar macrophages from humans and murine models for experimental purposes.

Alveolar macrophages are terminally differentiated, lung-resident macrophages of prenatal origin. Alveolar macrophages are unique in their long life and ...

Digestion of the Murine Liver for a Flow Cytometric Analysis of Lymphatic Endothelial Cells

Within the liver, lymphatic vessels are found within the portal triad, and their described function is to remove interstitial fluid from the liver to the lymph nodes where cellular debris and antigens can be surveyed. We are very interested in understanding how the lymphatic vasculature might be involved in inflammation and immune cell function within the liver. However, very little has been published establishing digestion protocols for the isolation of lymphatic endothelial cells (LECs) from the liver or specific markers that can be used to evaluate liver LECs on a per cell basis. Therefore, we optimized a method for the digestion and staining of the liver in order to evaluate the LEC population in the liver. We are confident that the method outlined here will be useful for the identification and isolation of LECs from the liver and will strengthen our understanding of how LECs respond to the liver microenvironment.

The goal of this protocol is to identify lymphatic endothelial cell populations within the liver using described markers. We utilize collagenase IV and DNase and a gentle mincing of tissue, combined with flow cytometry, to identify a distinct population of lymphatic endothelial cells.

Within the liver, lymphatic vessels are found within the portal triad, and their described function is to remove interstitial fluid from the liver to the ...