This work was supported by the Swedish Cancer Society (11 0253, 13 0469), the Swedish Research Council (K2012-99X-21959-01-3), Marcus Borgstr&#246;ms Foundation and the Swedish Research Council through a grant to the Uppsala RNA Research Centre (2006-5038-36531-16). We are indebted to the BioVis core facility at Uppsala University for much help with the FACS analysis.

The protocol describes the isolation of lymphoid cells from human patient material and therefore requires an ethical approval. The work done in the present study was granted by the Uppsala Ethical Review Board (Dnr. 2013/387).
1. Isolation of Mononuclear Cells (MNCs) from Human Palatine Tonsils
CAUTION: All unscreened material of human origin like blood, tissues or body fluids should be regarded as potentially infected material. Therefore, recommended biosafety practices for handling the human tissues should be followed.
Note: To avoid contamination,&#160;all solutions and cell culture equipment must be sterile. All buffers and solutions should be pre-cooled and kept on ice. Tonsil tissues and isolated cells should be kept and handled on ice.
<ol>
	<li>Obtain fresh tonsils from patients undergoing tonsillectomy or tonsillotomy (Figure 2). Plunge the tissue clumps into a 50 ml centrifuge tube filled with ice-cold sterile Hanks balanced salt solution (HBSS) supplemented with 5% fetal bovine serum (FBS), 10 mM Glutamine, 0.05 mg/ml Gentamicin and 1% Antibiotic-Antimycotic mix (Penicillin, Streptomycin and Amphotericin B).</li>
	<li>Keep the tubes with the submerged tonsil tissue samples at all times on ice. Try to process the tonsils as soon as possible, and no later than 3 hr after surgical removal.</li>
	<li>Place the tonsil on a 60 mm plastic cell culture plate on ice and keep the tissue moistened with HBSS. Remove visible blood clots, fatty and connective tissues with a clean forceps from the tonsil surface.</li>
	<li>Use a new 60 mm cell culture plate containing 5 ml HBSS. Cut the tonsil tissue clump into 3-10 mm fragments using a sterile pair of scissors and/or a scalpel.</li>
	<li>Prepare a new 60 mm cell culture plate containing 10 ml of HBSS and place a 100 &#181;m plastic cell strainer in the HBSS solution.</li>
	<li>Transfer the dissected tonsil fragments into the cell strainer with a sterile forceps. Using the plunger end of a plastic syringe, smoothly squeeze the tissue fragments through the cell strainer. Make sure that the tonsil fragments are totally immersed in the HBSS.</li>
	<li>Discard the cell strainer with the tissue remains and transfer the resulting cell suspension from the 60 mm cell culture plate into a 50 ml plastic centrifuge tube. Leave the tube on ice while proceeding with steps 1.8 and 1.9.</li>
	<li>In the case of big tonsils, larger than 2 cm in size (Figure 2), squeeze the tonsil fragments in two cell strainers to avoid clogging of the mesh in the strainer.</li>
	<li>Obtain the final volume of 35 ml of the cell suspension. 
	Note: At this step it is possible to prepare the cell suspension for cryopreservation (see section 2).</li>
	<li>Add 10 ml of density gradient solution such as Ficoll into a new 50 ml centrifuge tube. Gently overlay the cell suspension (step 1.9) on top of the density gradient solution. Avoid mixing of the cell suspension and the density gradient solution. 
	Note: The density gradient solution has to be warmed up to RT.</li>
	<li>Centrifuge the cell suspension in a swing-out rotor at 700 x g for 20 min at RT. Do not activate the brake function on the centrifuge as fast braking may disrupt the gradient. Also, use the lowest acceleration function available on the centrifuge. 
	Note: After this centrifugation step, observe MNCs as a fluffy white layer at the interface, and red blood cells (RBCs), fibroblasts and cell debris as the sediment at the bottom of the tube.</li>
	<li>Carefully collect the MNCs layer by using a 10 ml pipet. Place the cell suspension into a new 50 ml centrifuge tube.</li>
	<li>Add 25 ml of ice-cold PBS to the cell suspension and spin the tube at 300 x g for 5 min in a swing-out rotor at 4 &#176;C.</li>
	<li>Remove the supernatant using a 25 ml pipet and repeat cell pellet washing step two more times. Finally resuspend the cell pellet in 15 ml of PBS. 
	Note: After the final washing step, it is possible to cryopreserve the cell suspension (see section 2).</li>
	<li>Apply 10 &#181;l of cell suspension into hemocytometer cell counting chamber and count the cell number under a microscope. Dispense the appropriate amount of cells (e.g., 2-3 x 107) in a 15 ml centrifuge tube for subsequent magnetic bead separation. Keep this aliquot on ice until step 3.2.</li>
</ol>
2. Cryopreservation of Tonsillar Cells
<ol>
	<li>Prepare freezing medium (90% FBS and 10% DMSO) and keep it on ice. For long-term storage keep the freezing media at -20 &#176;C.</li>
	<li>Determine the total number of cells using a hemocytometer cell counting chamber (step 1.15). Calculate the required amount of freezing medium according to the desired frozen cell density (e.g., 107 cells/ml of freezing medium).</li>
	<li>Centrifuge the cell suspension at 300 x g for 5 min. Decant the supernatant without disturbing the cell pellet and resuspend the cell pellet in ice-cold freezing medium (from step 2.1).</li>
	<li>Dispense 1 ml aliquots of the cell suspension into sterile vials designed for long-term storage in liquid nitrogen.&#160;Freeze the vials in an isopropanol chamber and store them at &#8211;80 &#176;C O/N. For long-term preservation transfer the vials into a liquid nitrogen containing storage tank or a &#8211;140 &#176;C cell freezer.</li>
	<li>To thaw vials with frozen cells, warm them rapidly in a 37 &#176;C water bath. Immediately when thawed, disperse the cell suspension into 10 ml of pre-warmed HBSS (with supplements, step 1.1) in a 15 ml centrifuge tube. Spin the tube at 300 x g for 5 min, remove HBSS and resuspend the cell pellet at the desired cell density in HBSS (with supplements, step 1.1). 
	Note: The viability of the MNCs after thawing is of importance, since the presence of dead cells will decrease the final yield of purified B and T lymphocytes. 
	Note: According to our experience the cell viability less then 80% will reduce the cell isolation efficiency.</li>
</ol>
3. Positive Selection of T Lymphocyte Population from Tonsillar MNCs
Note 1: This protocol is based on positive selection of human CD3+ T lymphocytes from tonsillar MNCs using magnetic beads coupled to the CD3 antibody.&#160;It is possible to start this section from fresh (Section 1) or the frozen (Section 2) MNCs.
Note 2: Start with 3 x 107 MNCs. Do not exceed this cell number, since the separation columns may clog and this will reduce the isolation efficiency. Use bigger columns if more cells will be handled. The volumes used in this protocol have been experimentally optimized for the number of cells used in our experimental setup.
<ol>
	<li>Prepare the separation buffer [PBS (pH 7.2), 0.5% bovine serum albumin (BSA) and 2 mM EDTA]. Filter the separation buffer through a 0.45 &#181;m filter and store at 4 &#176;C.</li>
	<li>Spin the MNCs suspension (step 1.14) at 300 x g for 5 min at 4 &#176;C. Resuspend the resulting cell pellet in 240 &#181;l (80 &#181;l per 107 cells) of ice-cold separation buffer. Transfer the cell suspension into a sterile 2 ml tube.</li>
	<li>Add 20 &#181;l of CD3 magnetic antibody to the cell solution. Incubate the tubes for 1 hr at 4 &#176;C with continuous gentle mixing to keep cells in suspension.</li>
	<li>Transfer all of the cell suspension into a 15 ml tube containing 5 ml ice-cold separation buffer to wash the cells.</li>
	<li>Centrifuge the tube at 300 x g for 10 min at 4 &#176;C in a swing-out rotor.</li>
	<li>Meanwhile set up the magnetic separator and column. Attach the magnetic separator to the stand and place the column in the separator. Wash the column by applying 500 &#181;l of ice-cold separation buffer. Discard the flow through.</li>
	<li>Place a new 15 ml collection tube below the column. Keep the collection tube on ice.</li>
	<li>Discard the supernatant (step 3.5) by pipet and gently resuspend the cell pellet in 500 &#956;l separation buffer. Apply the cell suspension on top of the pre-washed column and let it run through. 
	Note: Cell clumps can clog the column and thus reduce the flow rate. To prevent this problem, place a 40 &#181;m plastic cell strainer on top of the column. Passing the cells through this mesh will highly improve the efficiency of this method.</li>
	<li>Wash the column 4 times with 1.5 ml of separation buffer (500 &#181;l for 107 cells). Wait for the column reservoir to be empty (no liquid should be observed in the column) before applying the next washing step. 
	Note: Obtain the CD3 unlabeled cells, considered as B lymphocyte fraction, as they are eluted into the collection tube.</li>
	<li>Remove the column from the separator and place into a new 15 ml collection tube. Pipette 2 ml of separation buffer onto the column. Using the plunger supplied with the column elute the positively selected T lymphocytes, which are regarded as the T lymphocyte fraction.</li>
	<li>Determine the number of purified cells (step 1.15) if necessary. Cell suspensions are now ready for downstream experiments.</li>
</ol>
4. Flow Cytometry Analysis of Isolated Tonsillar B and T Lymphocytes
CAUTION: Paraformaldehyde solution is irritant and suspected carcinogen. Wear suitable protective clothing, gloves, and eye/face protection.
Note 1: This protocol describes the method for direct staining of the isolated B and T cells by Fluorescence Activated Cell Sorting (FACS) analysis. The main purpose of this step is to assess the purity of the isolated cell populations after CD3 magnetic antibody separation. For this purpose established B and T cell markers, fluorophore-conjugated monoclonal antibodies CD20-FITC and CD2-APC, are used. Also the inclusion of isotype control antibodies is highly recommended to distinguish the non-specific &#8220;background&#8221; binding of the CD2 and CD20 antibodies (see step 4.8).
Note 2: It is possible to keep the purified cell fractions in a 1% paraformaldehyde (PFA) solution in the dark at 4 &#176;C until the time of staining (e.g., next day). Also the same procedure is applicable if there is a time gap between staining and FACS analysis. Remember that in both cases cells should be washed properly with PBSA (PBS containing 0.2% BSA) buffer, prior to staining or FACS analysis.
<ol>
	<li>Take out 6 x 106 cells of MNCs from step 1.15 (prior to applying to the column), B lymphocyte fraction from step 3.9 and T lymphocyte fraction from step 3.10.</li>
	<li>Spin the cell suspensions at 300 x g for 5 min at 4 &#176;C using a swing-out rotor.&#160;</li>
	<li>Remove the supernatant with pipet and wash the cell pellet once with 1 ml of ice-cold PBSA. Spin the cell suspensions at 300 x g for 5 min at 4 &#176;C. Remove the supernatant with pipet and resuspend the cells in 600 &#181;l of ice-cold PBSA buffer.</li>
	<li>Add 100 &#181;l of the cell suspension to the bottom of a FACS tube.</li>
	<li>Add 100 &#181;l of PBS containing 10% heat inactivated human serum to each tube, mix well and incubate for ~1 min at RT or 20 min on ice. 
	Note: B lymphocytes carry Fc receptors. In order to block the Fc receptors the purified cell fractions are incubated with 10% heat inactivated human serum. The human serum is heat inactivated by incubation at 56 &#176;C for 1 hr. Divide the heat inactivated serum into small aliquots and store frozen at -20 &#176;C.</li>
	<li>Centrifuge the cell suspension at 300 x g for 5 min at 4 &#176;C in a swing-out rotor.</li>
	<li>Remove the supernatant with pipet and wash the cell pellet with 1 ml PBSA. Repeat the centrifugation (300 x g for 5 min at 4 &#176;C).</li>
	<li>Add 100 &#181;l PBSA into each tube on ice. Add the appropriate amount of fluorophore-conjugated monoclonal antibody, according to the manufacturer&#8217;s recommendation (e.g., 20 &#181;l of anti-CD20 and/or 5 &#181;l of anti-CD2 antibodies in 100 &#181;l of PBSA). Note: Do not forget to assign enough control tubes for the FACS analysis. In this protocol the following controls should be included: 1) cells stained with the anti-CD2 and anti-CD20 antibodies individually, 2) cells stained with the anti-CD2 and anti-CD20 isotype control antibodies individually and, 3) cells without addition of antibodies.</li>
	<li>Briefly vortex the tube and incubate for 30 min at 4 &#176;C in the dark.</li>
	<li>Wash 2 times with PBSA. Add 2 ml of 1% PFA solution to the samples. Let the cells remain in the PFA solution at 4 &#176;C in dark till the time of FACS analysis.</li>
	<li>Immediately before running the samples in the FACS machine, wash the cells 2 times with PBSA (300 x g for 5 min at 4 &#176;C). Resuspend samples in 1 ml of PBS and keep at 4 &#176;C (or on ice), protected from light, prior to the separation on the flow cytometer.</li>
	<li>Do the FACS sorting following the protocol from the flow cytometer manufacturer.</li>
</ol>
5. PCR Detection of Adenovirus DNA in Isolated Tonsillar B and T Lymphocytes
Note 1: The adenovirus hexon gene primers are AdRJC1 (5&#8217;-GACATGACTTTCGAGGTCGATCCCATGGA-3&#8217;) and AdRJC2 (5&#8217;-CCGGCTGAGAAGGGTGTGCGCAGGTA-3&#8217;)11. These primers generate an amplicon of 139 bp. The host 18S rRNA gene can be detected with primers tp206 (5&#39;-CCCCTCGATGCTCTTAGCTG-3&#8217;) and tp207 (5&#39;-TCGTCTTCGAACCTCCGACT-3&#8217;). The expected amplicon size is 300 bp.
Note 2: Every PCR run includes a negative control (distilled H2O) and a positive DNA control obtained from human B cell line (BJAB) infected with human adenovirus type 512.
<ol>
	<li>Extract DNA (from at least 1 x 106 cells, step 3.11) using silica membrane based column purification method. Extract RNA using phenol and guanidine isothiocyanate solution13.</li>
	<li>Add 100 ng DNA from B and T lymphocytes to a reaction mixture containing 1x HF buffer, 0.2 mM of deoxynucleotide triphosphate mix (dNTP), 0.25 &#181;M of each primer and 1 U of High-Fidelity DNA polymerase in a total volume of 20 &#181;l.</li>
	<li>Perform PCR amplification under the following cycling conditions: 30 sec denaturation at 98 &#176;C, followed by 30 cycles of 98 &#176;C for 10 sec, 67 &#176;C (hexon) or 58 &#176;C (18S rRNA) for 30 sec and 72 &#176;C for 30 sec. The PCR reaction was ended with a final extension step of 7 min at 72 &#176;C.</li>
	<li>Separate the resulting PCR amplification products on a 1.5% agarose gel in 1x TBE buffer&#160;and visualize the expected bands by staining with nucleic acid stain.</li>
</ol>

<ol>
	<li>Nave, H., Gebert, A., Pabst, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphology+and+immunology+of+the+human+palatine+tonsil.">Morphology and immunology of the human palatine tonsil.</a> Anat Embryol (Berl). 204, 367-373 (2001).</li><li>Perry, M., Whyte, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunology+of+the+tonsils.">Immunology of the tonsils.</a> Immunology today. 19, 414-421 (1998).</li><li>Alkhalaf, M. A., Guiver, M., Cooper, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence+and+quantitation+of+adenovirus+DNA+from+human+tonsil+and+adenoid+tissues.">Prevalence and quantitation of adenovirus DNA from human tonsil and adenoid tissues.</a> J Med Virol. 85, 1947-1954 (2013).</li><li>Brandtzaeg, P., Halstensen, T. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunology+and+immunopathology+of+tonsils.">Immunology and immunopathology of tonsils.</a> Adv Otorhinolaryngol. 47, 64-75 (1992).</li><li>Imai, 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=Epstein-Barr+virus+(EBV)-carrying+and+-expressing+T-cell+lines+established+from+severe+chronic+active+EBV+infection.">Epstein-Barr virus (EBV)-carrying and -expressing T-cell lines established from severe chronic active EBV infection.</a> Blood. 87, 1446-1457 (1996).</li><li>Veen, J., Lambriex, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationship+of+adenovirus+to+lymphocytes+in+naturally+infected+human+tonsils+and+adenoids.">Relationship of adenovirus to lymphocytes in naturally infected human tonsils and adenoids.</a> Infect Immun. 7, 604-609 (1973).</li><li>Friedman, M., Wilson, M., Lin, H. C., Chang, H. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Updated+systematic+review+of+tonsillectomy+and+adenoidectomy+for+treatment+of+pediatric+obstructive+sleep+apnea/hypopnea+syndrome.">Updated systematic review of tonsillectomy and adenoidectomy for treatment of pediatric obstructive sleep apnea/hypopnea syndrome.</a> Otolaryngol Head Neck Surg. 140, 800-808 (2009).</li><li>Garnett, C. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Latent+species+C+adenoviruses+in+human+tonsil+tissues.">Latent species C adenoviruses in human tonsil tissues.</a> J Virol. 83, 2417-2428 (2009).</li><li>Garnett, C. T., Erdman, D., Xu, W., Gooding, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence+and+quantitation+of+species+C+adenovirus+DNA+in+human+mucosal+lymphocytes.">Prevalence and quantitation of species C adenovirus DNA in human mucosal lymphocytes.</a> J Virol. 76, 10608-10616 (2002).</li><li>Perez, M. E., Billordo, L. A., Baz, P., Fainboim, L., Arana, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+memory+B+cells+isolated+from+blood+and+tonsils+are+functionally+distinctive.">Human memory B cells isolated from blood and tonsils are functionally distinctive.</a> Immunol Cell Biol. 92, 882-887 (2014).</li><li>Cooper, R. J., Yeo, A. C., Bailey, A. S., Tullo, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adenovirus+polymerase+chain+reaction+assay+for+rapid+diagnosis+of+conjunctivitis.">Adenovirus polymerase chain reaction assay for rapid diagnosis of conjunctivitis.</a> Invest Ophthalmol Vis Sci. 40, 90-95 (1999).</li><li>Zhang, Y., Huang, W., Ornelles, D. A., Gooding, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+adenovirus+latency+in+human+lymphocyte+cell+lines.">Modeling adenovirus latency in human lymphocyte cell lines.</a> J Virol. 84, 8799-8810 (2010).</li><li>Chomczynski, P., Sacchi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-step+method+of+RNA+isolation+by+acid+guanidinium+thiocyanate-phenol-chloroform+extraction.">Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.</a> Anal. biochem. 162, 156-159 (1987).</li><li>Watanabe, T., Yoshizaki, K., Yagura, T., Yamamura, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+antibody+formation+by+human+tonsil+lymphocytes.">In vitro antibody formation by human tonsil lymphocytes.</a> J Immunol. 113, 608-616 (1974).</li></ol>

The authors have nothing to disclose.

One of the most important factors affecting the outcome of this protocol is the use of fresh tonsillar material as the starting material. Therefore, the tonsil samples should be processed within 3 hr after surgery. Tonsils could be obtained from both adults and children. The tonsillar material from the children is usually smaller due to the partial surgical removal of the tonsils (tonsillotomy). Therefore, the number of MNCs obtained from tonsillotomy samples (1 x 107-1 x 108) is less compared to to...

Tonsils are collections of incompletely encapsulated lymphoid tissues that lie under, and in contact with, the epithelium in the upper aero-digestive tract. Usually the term &#8220;tonsils&#8221; refers to the palatine tonsils situated at the lateral walls of the oral part of the pharynx. The paired palatine tonsils together with the nasopharyngeal tonsil (adenoid), paired tubal tonsils and lingual tonsils constitute the so-called &#8220;Waldeyer&#180;s ring&#8221;. The latter is responsible for the initial contact between inhaled or ingested pathogens and the lymphoid tissues of the aerodigestive tract1,2. Indeed, numerous reports have shown that both bacterial and viral antigens can be detected in palatine tonsil tissue samples2-6.
The palatine tonsils are composed of dense lymphoid tissue covered by a stratified squamous non-keratinising epithelium. The tonsils have numerous crypts, epithelial invaginations, which penetrate the parenchyma increasing the surface area. Histologically, the palatine tonsils contain numerous lymphoid follicles with germinal centers, which are the sites for B cell maturation and differentiation (B-cell areas). Likewise, the palatine tonsils encompass T cells, which are mainly located in the extrafollicular regions (T-cell areas). In addition to the B and T cells, also various follicular dendritic cells can be detected in palatine tonsils1,2. 
Due to their anatomic location, the palatine tonsils are easily accessible by surgical interventions. For example, surgical removal of tonsils, known as tonsillectomy, is routinely carried out worldwide7. In children with tonsillar hyperplasia, a partial surgical removal of the tonsils (tonsillotomy) is sometimes used, causing less postoperative pain to the patients. Considering the accumulation of various pathogens in tonsils, surgically removed tonsils provide a unique opportunity to study the influence of viral and bacterial agents on tonsillar lymphocyte functions2,8. Furthermore it is possible to study if some pathogens prefer to reside in specific cell subpopulations9. In addition, as the tonsils are rich source of B lymphocytes, isolated tonsillar B lymphocytes can be efficiently used to study the activity of different B cell subpopulations10. However, as the palatine tonsils contain a mixture of cell types an efficient method to separate the different cell subpopulations is needed. 
Here, we describe a simple method for efficient and rapid isolation of tonsillar B and T cell populations from human palatine tonsils by using a magnetic-activated cell separation technique (Figure 1). The method described here is useful for scientists who want to assess the role of different infectious agents in human lymphoid organs such as palatine tonsils.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Hanks balanced salt solution (HBSS)&#160;</td>
			<td>Gibco</td>
			<td>14175-053</td>
			<td>Contains 5% fetal bovine serum (FBS), 10 mM Glutamine,&#160;</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>&#160;0.05 mg/ml Gentamicin and 1% Antibiotic-Antimycotic mix</td>
		</tr>
		<tr>
			<td>Freezing medium</td>
			<td></td>
			<td></td>
			<td>90% FBS and 10% DMSO</td>
		</tr>
		<tr>
			<td>MACS buffer</td>
			<td></td>
			<td></td>
			<td>PBS (pH 7.2), 0.5% BSA and 2mM EDTA</td>
		</tr>
		<tr>
			<td>PBSA&#160;</td>
			<td></td>
			<td></td>
			<td>PBS containing 0.2% BSA</td>
		</tr>
		<tr>
			<td>PFA</td>
			<td></td>
			<td></td>
			<td>PBS containing 1% paraformaldehyde (PFA). Make fresh.</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>PFA is suspected carcinogen. Wear gloves and goggles.</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Antibiotic-Antimycotic mix</td>
			<td>Gibco</td>
			<td>15240-062</td>
			<td></td>
		</tr>
		<tr>
			<td>100-mm petridish</td>
			<td>Nunc</td>
			<td>172958</td>
			<td></td>
		</tr>
		<tr>
			<td>Dissecting foreceps</td>
			<td>Fisher Scientific</td>
			<td>1381241</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight iris scissors&#160;</td>
			<td>Fisher Scientific</td>
			<td>12912055</td>
			<td></td>
		</tr>
		<tr>
			<td>disposable scalpels</td>
			<td>Swann-Morton</td>
			<td>REF 0501</td>
			<td></td>
		</tr>
		<tr>
			<td>100&#956;m plastic cell strainer</td>
			<td>Corning Life Sciences</td>
			<td>352360</td>
			<td></td>
		</tr>
		<tr>
			<td>40&#956;m plastic cell strainers&#160;</td>
			<td>Corning Life Sciences</td>
			<td>352340</td>
			<td></td>
		</tr>
		<tr>
			<td>2-ml plastic syringe</td>
			<td>BD Biosciences&#160;</td>
			<td>300185</td>
			<td></td>
		</tr>
		<tr>
			<td>15-ml conical centrifuge tubes</td>
			<td>SARSTEDT</td>
			<td>62554502</td>
			<td></td>
		</tr>
		<tr>
			<td>50-ml conical centrifuge tubes</td>
			<td>SARSTEDT</td>
			<td>62547254</td>
			<td></td>
		</tr>
		<tr>
			<td>Low-speed centrifuge with fixed-angle or swinging-bucket rotor</td>
			<td colspan="2">Thermo Scientific Heraeus Megafuge 16R</td>
			<td></td>
		</tr>
		<tr>
			<td>Ficoll&#8211;Hypaque</td>
			<td>Sigma-Aldrich</td>
			<td>F5415-50ML</td>
			<td>Ficoll solution</td>
		</tr>
		<tr>
			<td>Fetal calf serum</td>
			<td>Biological industries</td>
			<td>040071A</td>
			<td></td>
		</tr>
		<tr>
			<td>Dimethyl sulphoxide (DMSO)</td>
			<td>SIGMA</td>
			<td colspan="2">D2650-5X5ML</td>
		</tr>
		<tr>
			<td>MACS MS columns&#160;</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-201</td>
			<td></td>
		</tr>
		<tr>
			<td>MACS human CD3 MicroBeads</td>
			<td>Miltenyi Biotec</td>
			<td>130-092-881</td>
			<td></td>
		</tr>
		<tr>
			<td>MACS separator (Octo MACS)</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-109</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>Merck Millipore</td>
			<td>1120180100</td>
			<td></td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>AnalaR NORMAPUR</td>
			<td>20302.293</td>
			<td></td>
		</tr>
		<tr>
			<td>CD2 conjugated to allophycocyanin (CD2-APC)&#160;</td>
			<td>BD Biosciences&#160;</td>
			<td>560642</td>
			<td></td>
		</tr>
		<tr>
			<td>CD20 conjugated to fluorescein isothiocyanate (CD20-FITC)&#160;</td>
			<td>BD Biosciences&#160;</td>
			<td>556632</td>
			<td></td>
		</tr>
		<tr>
			<td>Human serum&#160;</td>
			<td>Rockland Immunochemicals</td>
			<td>D119-0100</td>
			<td></td>
		</tr>
		<tr>
			<td>Phusion High-Fidelity DNA Polymerase</td>
			<td>Thermo Scientific</td>
			<td>F-530L</td>
			<td></td>
		</tr>
		<tr>
			<td>FACS tubes</td>
			<td>BD Falcon</td>
			<td>352003</td>
			<td></td>
		</tr>
		<tr>
			<td>Cryotube</td>
			<td>SARSTEDT</td>
			<td>72379</td>
			<td></td>
		</tr>
		<tr>
			<td>BD LSRII flowcytometer</td>
			<td>BD Biosciences&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>BD FACSDiva 4.1 software</td>
			<td>BD Biosciences&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Nucleospin Blood&#160;</td>
			<td>Macherey-Nagel</td>
			<td>740951.50</td>
			<td>DNA isolation kit</td>
		</tr>
		<tr>
			<td>TRIzol&#160; reagent</td>
			<td>Life technologies</td>
			<td>15596</td>
			<td>RNA isolation reagent</td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>The Paul Marienfeld GmbH &#38; Co. KG</td>
			<td>0610030</td>
			<td>cell counter device</td>
		</tr>
		<tr>
			<td>GelRed</td>
			<td>Biotium</td>
			<td align="right">41003</td>
			<td>Nucleic acid gel stain&#160;</td>
		</tr>
	</tbody>
</table>

efficient isolation protocol for b and t lymphocytes from human palatine tonsils

Tonsils form a part of the immune system providing the first line of defense against inhaled pathogens. Usually the term &#8220;tonsils&#8221; refers to the palatine tonsils situated at the lateral walls of the oral part of the pharynx. Surgically removed palatine tonsils provide a convenient accessible source of B and T lymphocytes to study the interplay between foreign pathogens and the host immune system. This video protocol describes the dissection and processing of surgically removed human palatine tonsils, followed by the isolation of the individual B and T cell populations from the same tissue sample. We present a method, which efficiently separates tonsillar B and T lymphocytes using an antibody-dependent affinity protocol. Further, we use the method to demonstrate that human adenovirus infects specifically the tonsillar T cell fraction. The established protocol is generally applicable to efficiently and rapidly isolate tonsillar B and T cell populations to study the role of different types of pathogens in tonsillar immune responses.

An efficient separation of tonsillar MNCs results in highly purified subpopulations of B and T lymphocytes. This was confirmed by FACS analysis using anti-CD20 and anti-CD2 antibodies to detect B and T lymphocyte populations, respectively (Figure 3A). In contrast, an inefficient separation of MNCs results in cell fractions that are a mixture of cells from both B and T lymphocyte subpopulations (Figure 3B).
The isolated tonsillar B and T lymphocytes (Fi...

Watch this Scientific Journal Video about Efficient Isolation Protocol for B and T Lymphocytes from Human Palatine Tonsils at JoVE.com

Efficient Isolation Protocol for B and T Lymphocytes from Human Palatine Tonsils

Palatine tonsils are a rich source of B and T lymphocytes. Here we provide an easy, efficient and rapid protocol to isolate B and T lymphocytes from human palatine tonsils. The method described has been specifically adapted for studies of the viral etiology of tonsil inflammation known as tonsillitis.

Tonsils form a part of the immune system providing the first line of defense against inhaled pathogens. Usually the term &#8220;tonsils&#8221; refers to ...

efficient-isolation-protocol-for-b-t-lymphocytes-from-human-palatine

Research

Education

JoVE Core

JoVE Journal

Medical-Surgical Nursing

Immunology and Infection

Unit 1

Upper Respiratory Tract Infections

SCIENTISTS IN ACTION

15.7K Görüntüleme.  Uppsala Biomedical Center, Uppsala University. Palatine tonsils are a rich source of B and T lymphocytes. Here we provide an easy, efficient and rapid protocol to isolate B and T lymphocytes from human palatine tonsils. The method described has been specifically adapted for studies of the viral etiology of tonsil inflammation known as tonsillitis.

Video: Efficient Isolation Protocol for B and T Lymphocytes from Human Palatine Tonsils

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 ...

Expanding Cytotoxic T Lymphocytes from Umbilical Cord Blood that Target Cytomegalovirus, Epstein-Barr Virus, and Adenovirus

Virus infections after stem cell transplantation are among the most common causes of death, especially after cord blood (CB) transplantation (CBT) where the CB does not contain appreciable numbers of virus-experienced T cells which can protect the recipient from infection.1-4 We and others have shown that virus-specific CTL generated from seropositive donors and infused to the recipient are safe and protective.5-8 However, until recently, virus-specific T cells could not be generated from cord blood, likely due to the absence of virus-specific memory T cells. 
In an effort to better mimic the in vivo priming conditions of na&iuml;ve T cells, we established a method that used CB-derived dendritic cells (DC) transduced with an adenoviral vector (Ad5f35pp65) containing the immunodominant CMV antigen pp65, hence driving T cell specificity towards CMV and adenovirus.9 At initiation, we use these matured DCs as well as CB-derived T cells in the presence of the cytokines IL-7, IL-12, and IL-15.10 At the second stimulation we used EBV-transformed B cells, or EBV-LCL, which express both latent and lytic EBV antigens. Ad5f35pp65-transduced EBV-LCL are used to stimulate the T cells in the presence of IL-15 at the second stimulation. Subsequent stimulations use Ad5f35pp65-transduced EBV-LCL and IL-2. 
From 50x106 CB mononuclear cells we are able to generate upwards of 150 x 106 virus-specific T cells that lyse antigen-pulsed targets and release cytokines in response to antigenic stimulation.11 These cells were manufactured in a GMP-compliant manner using only the 20% fraction of a fractionated cord blood unit and have been translated for clinical use.

Here we describe the first good manufacturing practice (GMP)-compliant method of producing virus-specific cytotoxic T lymphocytes (CTL) from umbilical cord blood, a source of predominantly na&#238;ve T cells.

Virus infections after stem cell transplantation are among the most common causes of death, especially after cord blood (CB) transplantation (CBT) where ...

Isolation of Lymphocytes from Mouse Genital Tract Mucosa

Mucosal surfaces, including in the gastrointestinal, urogenital, and respiratory tracts, provide portals of entry for pathogens, such as viruses and bacteria 1. Mucosae are also inductive sites in the host to generate immunity against pathogens, such as the Peyers patches in the intestinal tract and the nasal-associated lymphoreticular tissue in the respiratory tract. This unique feature brings mucosal immunity as a crucial player of the host defense system. Many studies have been focused on gastrointestinal and respiratory mucosal sites. However, there has been little investigation of reproductive mucosal sites. The genital tract mucosa is the primary infection site for sexually transmitted diseases (STD), including bacterial and viral infections. STDs are one of the most critical health challenges facing the world today. Centers for Disease Control and Prevention estimates that there are 19 million new infectious every year in the United States. STDs cost the U.S. health care system $17 billion every year 2, and cost individuals even more in immediate and life-long health consequences. In order to confront this challenge, a greater understanding of reproductive mucosal immunity is needed and isolating lymphocytes is an essential component of these studies. Here, we present a method to reproducibly isolate lymphocytes from murine female genital tracts for immunological studies that can be modified for adaption to other species. The method described below is based on one mouse.&#x2003;

An efficient way to isolate lymphocytes from mouse genital tract is described. This method takes advantage of enzyme digestion and Percoll gradient separation to allow efficient isolation. This technique is also adaptable to for use in other species

Mucosal surfaces, including in the gastrointestinal, urogenital, and respiratory tracts, provide portals of entry for pathogens, such as viruses and ...

Isolation of Precursor B-cell Subsets from Umbilical Cord Blood

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

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

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

Isolation and Th17 Differentiation of Na&iuml;ve CD4 T Lymphocytes

Th17 cells are a distinct subset of T cells that have been found to produce interleukin 17 (IL-17), and differ in function from the other T cell subsets including Th1, Th2, and regulatory T cells. Th17 cells have emerged as a central culprit in overzealous inflammatory immune responses associated with many autoimmune disorders. In this method we purify T lymphocytes from the spleen and lymph nodes of C57BL/6 mice, and stimulate purified CD4+ T cells under control and Th17-inducing environments. The Th17-inducing environment includes stimulation in the presence of anti-CD3 and anti-CD28 antibodies, IL-6, and TGF-&#946;. After incubation for at least 72 hours and for up to five days at 37 &#176;C, cells are subsequently analyzed for the capability to produce IL-17 through flow cytometry, qPCR, and ELISAs. Th17 differentiated CD4+CD25- T cells can be utilized to further elucidate the role that Th17 cells play in the onset and progression of autoimmunity and host defense. Moreover, Th17 differentiation of CD4+CD25- lymphocytes from distinct murine knockout/disease models can contribute to our understanding of cell fate plasticity.

Isolation and Th17 Differentiation of Na&amp;#239;ve CD4 T Lymphocytes

With effector functions distinct from other T cell subsets, Th17 cells have been centrally implicated in inflammatory autoimmunity. This in vitro Th17 differentiation protocol provides a means to determine whether na&#239;ve CD4+ T lymphocytes can differentiate into Th17 cells, and to further examine their role in autoimmunity and host response.

Th17 cells are a distinct subset of T cells that have been found to produce interleukin 17 (IL-17), and differ in function from the other T cell subsets ...

Rapid Analysis of Chromosome Aberrations in Mouse B Lymphocytes by PNA-FISH

Defective DNA repair leads to increased genomic instability, which is the root cause of mutations that lead to tumorigenesis. Analysis of the frequency and type of chromosome aberrations in different cell types allows defects in DNA repair pathways to be elucidated. Understanding mammalian DNA repair biology has been greatly helped by the production of mice with knockouts in specific genes. The goal of this protocol is to quantify genomic instability in mouse B lymphocytes. Labeling of the telomeres using PNA-FISH probes (peptide nucleic acid - fluorescent in situ hybridization) facilitates the rapid analysis of genomic instability in metaphase chromosome spreads. B cells have specific advantages relative to fibroblasts, because they have normal ploidy and a higher mitotic index. Short-term culture of B cells therefore enables precise measurement of genomic instability in a primary cell population which is likely to have fewer secondary genetic mutations than what is typically found in transformed fibroblasts or patient cell lines.

DNA repair pathways are essential for maintenance of genomic integrity and preventing mutation and cancer. The goal of this protocol is to quantify genomic instability by direct observation of chromosome aberrations in metaphase spreads from mouse B cells using fluorescent in situ hybridization (FISH) for telomeric DNA repeats.

Defective DNA repair leads to increased genomic instability, which is the root cause of mutations that lead to tumorigenesis. Analysis of the frequency ...

Highly Efficient Transfection of Human THP-1 Macrophages by Nucleofection

Macrophages, as key players of the innate immune response, are at the focus of research dealing with tissue homeostasis or various pathologies. Transfection with siRNA and plasmid DNA is an efficient tool for studying their function, but transfection of macrophages is not a trivial matter. Although many different approaches for transfection of eukaryotic cells are available, only few allow reliable and efficient transfection of macrophages, but reduced cell vitality and severely altered cell behavior like diminished capability for differentiation or polarization are frequently observed. Therefore a transfection protocol is required that is capable of transferring siRNA and plasmid DNA into macrophages without causing serious side-effects thus allowing the investigation of the effect of the siRNA or plasmid in the context of normal cell behavior. The protocol presented here provides a method for reliably and efficiently transfecting human THP-1 macrophages and monocytes with high cell vitality, high transfection efficiency, and minimal effects on cell behavior. This approach is based on Nucleofection and the protocol has been optimized to maintain maximum capability for cell activation after transfection. The protocol is adequate for adherent cells after detachment as well as cells in suspension, and can be used for small to medium sample numbers. Thus, the method presented is useful for investigating gene regulatory effects during macrophage differentiation and polarization. Apart from presenting results characterizing macrophages transfected according to this protocol in comparison to an alternative chemical method, the impact of cell culture medium selection after transfection on cell behavior is also discussed. The presented data indicate the importance of validating the selection for different experimental settings.

This protocol presents an efficient and reliable method to transfect human THP-1 macrophages with siRNA or plasmid DNA by electroporation with high transfection efficiency while maintaining high cell vitality and full macrophage capacity for differentiation and polarization.

Macrophages, as key players of the innate immune response, are at the focus of research dealing with tissue homeostasis or various pathologies. ...

A Simple and Rapid Protocol to Non-enzymatically Dissociate Fresh Human Tissues for the Analysis of Infiltrating Lymphocytes

The ability of malignant cells to evade the immune system, characterized by tumor escape from both innate and adaptive immune responses, is now accepted as an important hallmark of cancer. Our research on breast cancer focuses on the active role that tumor infiltrating lymphocytes play in tumor progression and patient outcome. Toward this goal, we developed a methodology for the rapid isolation of intact lymphoid cells from normal and abnormal tissues in an effort to evaluate them proximate to their native state. Homogenates prepared using a mechanical dissociator show both increased viability and cell recovery while preserving surface receptor expression compared to enzyme-digested tissues. Furthermore, enzymatic digestion of the remaining insoluble material did not recover additional CD45+ cells indicating that quantitative and qualitative measurements in the primary homogenate likely genuinely reflect infiltrating subpopulations in the tissue fragment. The lymphoid cells in these homogenates can be easily characterized using immunological (phenotype, proliferation, etc.) or molecular (DNA, RNA and/or protein) approaches. CD45+ cells can also be used for subpopulation purification, in vitro expansion or cryopreservation. An additional benefit of this approach is that the primary tissue supernatant from the homogenates can be used to characterize and compare cytokines, chemokines, immunoglobulins and antigens present in normal and malignant tissues. This protocol functions extremely well for human breast tissues and should be applicable to a wide variety of normal and abnormal tissues.

This protocol describes the rapid non-enzymatic dissociation of fresh human tissue fragments for qualitative and quantitative assessment of CD45+ cells (lymphocytes/leukocytes) present in various normal and malignant human tissues. Additionally, the supernatant obtained from the primary tissue homogenate can be collected and stored for further analysis or experimentation.

The ability of malignant cells to evade the immune system, characterized by tumor escape from both innate and adaptive immune responses, is now accepted ...

Generation of Recombinant Human IgG Monoclonal Antibodies from Immortalized Sorted B Cells

Finding new methods for generating human monoclonal antibodies is an active research field that is important for both basic and applied sciences, including the development of immunotherapeutics. However, the techniques to identify and produce such antibodies tend to be arduous and sometimes the heavy and light chain pair of the antibodies are dissociated. Here, we describe a relatively simple, straightforward protocol to produce human recombinant monoclonal antibodies from human peripheral blood mononuclear cells using immortalization with Epstein-Barr Virus (EBV) and Toll-like receptor 9 activation. With an adequate staining, B cells producing antibodies can be isolated for subsequent immortalization and clonal expansion. The antibody transcripts produced by the immortalized B cell clones can be amplified by PCR, sequenced as corresponding heavy and light chain pairs and cloned into immunoglobulin expression vectors. The antibodies obtained with this technique can be powerful tools to study relevant human immune responses, including autoimmunity, and create the basis for new therapeutics.

Synthesis of human monoclonal antibodies is the first step in studies aimed at unraveling the pathophysiological mechanisms of auto-antibody-mediated immune responses. We have developed a protocol to generate recombinant human immunoglobulin G (IgG) monoclonal antibodies from blood sorted B cells, including B-cell isolation, antibody cloning and in vitro synthesis.

Finding new methods for generating human monoclonal antibodies is an active research field that is important for both basic and applied sciences, ...

In Vitro Differentiation of Human CD4+FOXP3+ Induced Regulatory T Cells (iTregs) from Na&#239;ve CD4+ T Cells Using a TGF-&#946;-containing Protocol

Regulatory T cells (Tregs) are an integral part of peripheral tolerance, suppressing immune reactions against self-structures and thus preventing autoimmune diseases. Clinical approaches to adoptively transfer Tregs, or to deplete Tregs in cancer, are underway with promising first outcomes. 
Because the number of naturally occurring Tregs (nTregs) is very limited, studying certain Treg features using in vitro induced Tregs (iTregs) can be advantageous. To date, the best although not absolutely specific protein marker to delineate Tregs is the transcription factor FOXP3. Despite the importance of Tregs including non-redundant roles of peripherally induced Tregs, the protocols to generate iTregs are currently controversial, particularly for human cells. This protocol therefore describes the in vitro differentiation of human CD4+FOXP3+ iTregs from human na&#239;ve T cells using a range of Treg-inducing factors (TGF-&#946; plus IL-2 only, or their combination with retinoic acid, rapamycin or butyrate) in parallel. It also describes the phenotyping of these cells by flow cytometry and qRT-PCR. 
These protocols result in reproducible expression of FOXP3 and other Treg signature genes and enable the study of general FOXP3-regulatory mechanisms as well as protocol-specific effects to delineate the impact of certain factors. iTregs can be utilized to study various phenotypic aspects as well as molecular mechanisms of Treg induction. Detailed molecular studies are facilitated by relatively large cell numbers that can be obtained. 
A limitation for the application of iTregs is the relative instability of FOXP3 expression in these cells compared to nTregs. iTregs generated by these protocols can also be used for functional assays such as studying their suppressive function, in which iTregs induced by TGF-&#946; plus retinoic acid and rapamycin display superior suppressive activity. However, the suppressive capacity of iTregs can differ from nTregs and the use of appropriate controls is crucial.

&lt;em&gt;In Vitro&lt;/em&gt; Differentiation of Human CD4&lt;sup&gt;+&lt;/sup&gt;FOXP3&lt;sup&gt;+&lt;/sup&gt; Induced Regulatory T Cells (iTregs) from Na&amp;#239;ve CD4&lt;sup&gt;+&lt;/sup&gt; T Cells Using a TGF-&amp;#946;-containing Protocol

This protocol describes the reproducible generation and phenotyping of human induced regulatory T cells (iTregs) from na&#239;ve CD4+ T cells in vitro. Different protocols for FOXP3 induction allow for the study of specific iTreg phenotypes obtained with respective protocols.