<p class="jove_content">We thank Dick Foley and Leigh Kimball for their key roles in filming and video production.</p>

<p class="jove_title">1. Peripheral blood mononuclear cell (PBMC) isolation</p>
<ol>
<li>Obtain a blood sample &ndash; blood should be collected in syringes or blood tubes and anti-coagulated with heparin (1:50 ratio) to prevent clotting.  Expect a yield of about 1&times;10<sup>6</sup> PBMC per mL of blood &ndash; about 40% of which will be CD4 positive (CD4+) T cells.</li>
<li>Aliquot the blood into 50 mL conical tubes, 25 mL per tube.  If blood has separated, gently mix before aliquoting to distribute the plasma</li>
<li>Add PBS, bringing the...

<ol>
	<li>Novak, E. J., Liu, A. W., Nepom, G. T., Kwok, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MHC+Class+II+tetramers+permit+detection+and+characterization+of+peptide-specific+human+CD4++T+cells+proliferating+to+influenza+A+antigen.">MHC Class II tetramers permit detection and characterization of peptide-specific human CD4+ T cells proliferating to influenza A antigen.</a> <em style='font-style: italic'>J. Clin. Invest</em>. <b>104</b>, R63-R67 (1999).</li><li>Novak, E. J., Liu, A. W., Gebe, J. A., Falk, B., Nepom, G. T., Falk, B., Koelle, D. M., Kwok, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tetramer-guided+epitope+mapping:+rapid+identification+and+characterization+of+immunodominant+CD4++T+cell+epitopes+from+complex+antigens.">Tetramer-guided epitope mapping: rapid identification and characterization of immunodominant CD4+ T cell epitopes from complex antigens.</a> <em style='font-style: italic'>J. Immunol</em>. <b>166</b>, 6665-6670 (2001).</li></ol>

<p class="jove_content">Understanding the role of CD4+ T cells in immunity is fundamentally important.  However, antigen specific CD4+ T cells can be difficult to detect and isolate using traditional methods.  In contrast, MHC class II tetramers allow the direct visualization of CD4+ T cells with the desired antigen specificity.  This video demonstrates the isolation, purification, and in vitro amplification of CD4+ T cells and their subsequent visualization using tetramers.  Class II Tetramers are fluorescent protein conjugates consisting of s...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Class 2 Laminar flow biosafety cabinet</td>
<td>equipment</td>
<td>Thermo Forma</td>
<td>1200</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>50 mL conical Tube</td>
<td>equipment</td>
<td>VWR</td>
<td>47747-182</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>1X PBS (Ca/Mg free)</td>
<td>Reagent</td>
<td>HyClone</td>
<td>SH30028.02</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Ficoll-paque PLUS</td>
<td>Reagent</td>
<td>GE Healthcare</td>
<td>17-1440-03</td>
<td>foil wrapped to protect from light</td>
</tr>
<tr>
<td>Pipet Aid XP</td>
<td>equipment</td>
<td>Drummond</td>
<td>4-000-101</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>10 mL pipet</td>
<td>equipment</td>
<td>Corning/Costar</td>
<td>CLS4492</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Aerosolve Canisters</td>
<td>equipment</td>
<td>Beckman</td>
<td>359481</td>
<td>with 50 mL inserts</td>
</tr>
<tr>
<td>Centrifuge</td>
<td>equipment</td>
<td>Beckman</td>
<td>GS-6R</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Transfer pipets </td>
<td>equipment</td>
<td>Samco</td>
<td>202-20S</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Pasteur pipets</td>
<td>equipment</td>
<td>VWR</td>
<td>14672-200</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Hemolytic Buffer</td>
<td>Reagent</td>
<td>N/A</td>
<td>N/A</td>
<td>8.3 g/L NH4Cl, 1.0 g/L NaHCO3, 0.04 g/L disodium EDTA</td>
</tr>
<tr>
<td>Trypan blue</td>
<td>Reagent</td>
<td>Sigma</td>
<td>T6146</td>
<td>0.2% in PBS</td>
</tr>
<tr>
<td>Hemocytometer</td>
<td>equipment</td>
<td>VWR </td>
<td>15170-208</td>
<td>&nbsp;</td>
<tr>
<td>15 mL conical tube</td>
<td>equipment</td>
<td>VWR</td>
<td>05-527-90</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Running Buffer</td>
<td>Reagent</td>
<td>N/A</td>
<td>N/A</td>
<td>PBS + 2mM EDTA + 5g/L BSA</td>
</tr>
<tr>
<td>MACS CD4+ T Cell Isolation Kit II</td>
<td>Reagent</td>
<td>Miltenyi Biotec</td>
<td>130-091-155</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>EasySep&reg;   Magnet</td>
<td>equipment</td>
<td>Stem Cell Technologies</td>
<td>18000</td>
<td>		</td>
</tr>
<tr>
<td>5 mL polypropylene tube</td>
<td>equipment</td>
<td>Falcon</td>
<td>352063</td>
<td>		</td>
</tr>
<tr>
<td>RPMI 1640</td>
<td>Reagent</td>
<td> Invitrogen</td>
<td>22400-089</td>
<td>with 25 mM HEPES</td>
</tr>
<tr>
<td>Pooled human serum</td>
<td>Reagent</td>
<td>N/A</td>
<td>N/A</td>
<td>drawn from healthy donors, heat inactivated and filtered</td>
</tr>
<tr>
<td>Pen Strep</td>
<td>Reagent</td>
<td>Invitrogen</td>
<td>1570-063</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>500mL 0.22 micron bottle top filter</td>
<td>equipment</td>
<td>Nalgene</td>
<td>595-3320</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>48-well plate</td>
<td>equipment</td>
<td>Costar</td>
<td>3548</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>37&deg;C CO<sub>2</sub> incubator</td>
<td>equipment</td>
<td>Sanyo Scientific</td>
<td>MCO-18AIC</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>20 mg/mL synthetic peptide</td>
<td>Reagent</td>
<td>N/A</td>
<td>N/A</td>
<td>Custom synthesis from any peptide vendor</td>
</tr>
<tr>
<td>5 mL FACS tube</td>
<td>equipment</td>
<td>Falcon</td>
<td>352008</td>
<td>Polystyrene</td>
</tr>
<tr>
<td>Peptide loaded class II tetramer (as described)</td>
<td>Reagent</td>
<td>N/A</td>
<td>N/A</td>
<td>Prepared by the BRI tetramer core</td>
</tr>
<tr>
<td>Anti-CD3</td>
<td>Reagent</td>
<td>BD pharmingen</td>
<td>347344</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Anti-CD4</td>
<td>Reagent</td>
<td>eBioscience</td>
<td>17-0049-73</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Anti-CD25</td>
<td>Reagent</td>
<td>eBioscience</td>
<td>11-0259-73</td>
<td>Or equivalent</td>
</tr>
<tr>
<td>Facs Calibur Flow Cytometer</td>
<td>equipment</td>
<td>BD Biosciences</td>
<td>342975</td>
<td>Or equivalent</td>
</tr>		</tbody>
		</table>
		</div>
	

visualizing antigen specific cd4+ t cells using mhc class ii tetramers

Major histocompatibility complex (MHC) class II tetramers allow the direct visualization of antigen specific CD4+ T cells by flow cytometry.  This method relies on the highly specific interaction between peptide loaded MHC and the corresponding T-cell receptor.  While the affinity of a single MHC/peptide molecule is low, cross-linking MHC/peptide complexes with streptavidin increases the avidity of the interaction, enabling their use as staining reagents.  Because of the relatively low frequencies of CD4+ T cells (~1 in 300,000 for a single specificity) this assay utilizes an in vitro amplification step to increase its threshold of detection.  Mononuclear cells are purified from peripheral blood by Ficoll underlay.  CD4+ cells are then separated by negative selection using biotinylated antibody cocktail and anti-biotin labeled magnetic beads.  Using adherent cells from the CD4- cell fraction as antigen presenting cells, CD4+ T cells are expanded in media by adding an antigenic peptide and IL-2.  The expanded cells are stained with the corresponding class II tetramer by incubating at 37 C for one hour and subsequently stained using surface antibodies such as anti-CD4, anti-CD3, and anti-CD25.  After labeling, the cells can be directly analyzed by flow cytometry.  The tetramer positive cells typically form a distinct population among the expanded CD4+ cells.  Tetramer positive cells are usually CD25+ and often CD4 high.  Because the level of background tetramer staining can vary, positive staining results should always be compared to the staining of the same cells with an irrelevant tetramer.  Multiple variations of this basic assay are possible.  Tetramer positive cells may be sorted for further phenotypic analysis, inclusion in ELISPOT or proliferation assays, or other secondary assays.  Several groups have also demonstrated co-staining using tetramers and either anti-cytokine or anti-FoxP3 antibodies.  

Watch this Scientific Journal Video about Visualizing Antigen Specific CD4+ T Cells using MHC Class II Tetramers at JoVE.com

Visualizing Antigen Specific CD4+ T Cells using MHC Class II Tetramers

<p class="jove_content">This procedure demonstrates the purification and in vitro expansion of antigen specific CD4+ T cells from whole peripheral blood and their visualization using MHC class II tetramers.  Tetramers permit the direct visualization of T cells with a single antigen specificity and defined MHC class II restriction.
</p>

Major histocompatibility complex (MHC) class II tetramers allow the direct visualization of antigen specific CD4+ T cells by flow cytometry.  This method ...

visualizing-antigen-specific-cd4-t-cells-using-mhc-class-ii-tetramers

Research

JoVE Journal

Biology

21.5K Views.  Benaroya Research Institute. Questa procedura dimostra la purificazione e l'espansione in vitro di cellule CD4 + antigene specifico le cellule T del sangue periferico da tutto e la loro visualizzazione utilizzando tetrameri MHC di classe II. Tetrameri consentire la visualizzazione diretta delle cellule T con una singola specificità antigenica e definito MHC di classe II restrizione.