This work was supported by Public Health Service grants from the National Institutes of Health (T32 DA007097, R01AI096966, andUM1AI26617).

1. Day 1: Fresh Tissue Sectioning and Primary Incubation
<ol>
	<li>Use a scalpel to cut fresh tissue into small (approximately 0.5 cm wide by 0.5 cm tall) pieces. Separately glue each tissue to a plunger and embed them with 3 - 5 mL of 4% low-melt agarose in PBS. Label the plunger with the tissue information using a sticker. Put it in a chilled holder in an ice bucket to solidify.</li>
	<li>Turn on the microtome and set the thickness of the sections to 200 &#181;m. Install a razor blade on the microtome and insert the ...

<ol>
	<li>Altman, J. D., 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=Phenotypic+analysis+of+antigen-specific+T+lymphocytes.">Phenotypic analysis of antigen-specific T lymphocytes.</a> Science. 274 (5284), 94-96 (1996).</li><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+identify+peptide-specific+human+CD4(+)+T+cells+proliferating+in+response+to+influenza+A+antigen.">MHC Class II tetramers identify peptide-specific human CD4(+) T cells proliferating in response to influenza A antigen.</a> J Clin Invest. 104, R63-R67 (1999).</li><li>Steinert, E. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+memory+CD8+T+cells+reveals+regionalization+of+immunosurveillance.">Quantifying memory CD8 T cells reveals regionalization of immunosurveillance.</a> Cell. 161 (4), 737-749 (2015).</li><li>Skinner, P. J., Daniels, M. A., Schmidt, C. S., Jameson, S. C., 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=Cutting+edge:+In+situ+tetramer+staining+of+antigen-specific+T+cells+in+tissues.">Cutting edge: In situ tetramer staining of antigen-specific T cells in tissues.</a> J Immunol. 165 (2), 613-617 (2000).</li><li>Haanen, J. 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=In+situ+detection+of+virus-+and+tumor-specific+T-cell+immunity.">In situ detection of virus- and tumor-specific T-cell immunity.</a> Nat Med. 6 (9), 1056-1060 (2000).</li><li>Skinner, P. J., 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=In+situ+tetramer+staining+using+MHC+class+I+tetramers.">In situ tetramer staining using MHC class I tetramers.</a> J Immunol Methods. 268 (1), 29-34 (2002).</li><li>Skinner, P. J., 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=In+situ+staining+using+MHC+class+I+tetramers.">In situ staining using MHC class I tetramers.</a> Curr Protoc Immunol. 17, 4.1-4.9 (2004).</li><li>Li, Y., 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=Use+of+HLA-DR*08032/E7+and+HLA-DR*0818/E7+tetramers+in+tracking+of+epitope-specific+CD4++T+cells+in+active+and+convalescent+tuberculosis+patients+compared+with+control+donors.">Use of HLA-DR*08032/E7 and HLA-DR*0818/E7 tetramers in tracking of epitope-specific CD4+ T cells in active and convalescent tuberculosis patients compared with control donors.</a> Immunobiology. 216, 947-960 (2011).</li><li>Bischof, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+autoreactive+CD4+T+cells+in+experimental+autoimmune+encephalomyelitis+after+primary+and+secondary+challenge+using+MHC+class+II+tetramers.">Analysis of autoreactive CD4 T cells in experimental autoimmune encephalomyelitis after primary and secondary challenge using MHC class II tetramers.</a> J Immunol. 172, 2878-2884 (2004).</li><li>Massilamany, 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=Direct+staining+with+major+histocompatibility+complex+class+II+dextramers+permits+detection+of+antigen-specific,+autoreactive+CD4+T+cells+in+situ.">Direct staining with major histocompatibility complex class II dextramers permits detection of antigen-specific, autoreactive CD4 T cells in situ.</a> PLoS ONE. 9, e87519 (2014).</li><li>Massilamany, 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=In+situ+detection+of+autoreactive+CD4+T+cells+in+brain+and+heart+using+major+histocompatibility+complex+class+II+dextramers.">In situ detection of autoreactive CD4 T cells in brain and heart using major histocompatibility complex class II dextramers.</a> J Vis Exp. (90), e51679 (2014).</li><li>Dileepan, T., Kim, H. O., Cleary, P. P., Skinner, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Situ+Peptide-MHC-II+Tetramer+Staining+of+Antigen-Specific+CD4++T+Cells+in+Tissues.">In Situ Peptide-MHC-II Tetramer Staining of Antigen-Specific CD4+ T Cells in Tissues.</a> PLoS ONE. 10 (6), e0128862 (2015).</li><li>Tjernlund, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+detection+of+Gag-specific+CD8++cells+in+the+GI+tract+of+SIV+infected+Rhesus+macaques.">In situ detection of Gag-specific CD8+ cells in the GI tract of SIV infected Rhesus macaques.</a> Retrovirology. 7, 7-12 (2010).</li><li>Connick, E., 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=CTL+fail+to+accumulate+at+sites+of+HIV-1+replication+in+lymphoid+tissue.">CTL fail to accumulate at sites of HIV-1 replication in lymphoid tissue.</a> J Immunol. 178, 6975-6983 (2007).</li><li>Hong, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Localized+Populations+of+CD8low/&#8722;+MHC+Class+I+Tetramer++SIV-Specific+T+Cells+in+Lymphoid+Follicles+and+Genital+Epithelium.">Localized Populations of CD8low/&#8722; MHC Class I Tetramer+ SIV-Specific T Cells in Lymphoid Follicles and Genital Epithelium.</a> PLoS ONE. 4 (1), e4131 (2009).</li><li>Sasikala-Appukuttan, A. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Location+and+dynamics+of+the+immunodominant+CD8+T+cell+response+to+SIV&#916;nef+immunization+and+SIVmac251+vaginal+challenge.">Location and dynamics of the immunodominant CD8 T cell response to SIV&#916;nef immunization and SIVmac251 vaginal challenge.</a> PLoS ONE. 8 (12), e81623 (2013).</li><li>Connick, E., 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=Compartmentalization+of+simian+immunodeficiency+virus+replication+within+secondary+lymphoid+tissues+of+rhesus+macaques+is+linked+to+disease+stage+and+inversely+related+to+localization+of+virus-specific+CTL.">Compartmentalization of simian immunodeficiency virus replication within secondary lymphoid tissues of rhesus macaques is linked to disease stage and inversely related to localization of virus-specific CTL.</a> J Immunol. 193, 5613-5625 (2014).</li><li>Li, Q., 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=Visualizing+antigen-specific+and+infected+cells+in+situ+predicts+outcomes+in+early+viral+infection.">Visualizing antigen-specific and infected cells in situ predicts outcomes in early viral infection.</a> Science. 323, 1726-1729 (2009).</li><li>Li, Q., Skinner, P. J., Duan, L., 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=A+technique+to+simultaneously+visualize+virus-specific+CD8++T+cells+and+virus-infected+cells+in+situ.">A technique to simultaneously visualize virus-specific CD8+ T cells and virus-infected cells in situ.</a> J Vis Exp. (30), e1561 (2009).</li><li>Li, 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=Simian+immunodeficiency+virus-producing+cells+in+follicles+are+partially+suppressed+by+CD8++cells+in+vivo.">Simian immunodeficiency virus-producing cells in follicles are partially suppressed by CD8+ cells in vivo.</a> J Virol. 90, 11168-11180 (2016).</li><li>Daniels, M. A., Jameson, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Critical+role+for+CD8+in+T+cell+receptor+binding+and+activation+by+peptide/major+histocompatibility+complex+multimers.">Critical role for CD8 in T cell receptor binding and activation by peptide/major histocompatibility complex multimers.</a> J Exp Med. 191, 335-346 (2000).</li><li>Lee, Y. J., Wang, H., Starrett, G. J., Phuong, V., Jameson, S. C., Hogquist, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+specific+distribution+of+iNKT+cells+impacts+their+cytokine+response.">Tissue specific distribution of iNKT cells impacts their cytokine response.</a> Immunity. 43 (3), 566-578 (2015).</li><li>Abdelaal, H. M., Kim, H. O., Wagstaff, R., Sawahata, R., Southern, P. J., Skinner, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+Vibratome+and+Compresstome+sectioning+of+fresh+primate+lymphoid+and+genital+tissues+for+in+situ+MHC-tetramer+and+immunofluorescence+staining.">Comparison of Vibratome and Compresstome sectioning of fresh primate lymphoid and genital tissues for in situ MHC-tetramer and immunofluorescence staining.</a> Biol Proced Online. 17, (2015).</li><li>Wang, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNAscope:+a+novel+in+situ+RNA+analysis+platform+for+formalin-fixed,+paraffin-embedded+tissues.">RNAscope: a novel in situ RNA analysis platform for formalin-fixed, paraffin-embedded tissues.</a> J Mol Diagn. 14 (1), 22-29 (2012).</li></ol>

IST combined with IHC provides an essential tool for detecting, characterizing, and quantifying antigen-specific CD8 T cells in native environments with the context of other cells and tissue structures. Here, we described detailed procedures for IST combined with IHC, followed by quantitative image analysis, to determine the location, abundance, and phenotype of antigen-specific CD8 T cells in lymph nodes from rhesus macaques. Similar staining can be applied to human, mouse, or other species tissues for which MHC-I tetra...

T cells are critical to many immunological processes, including detecting and eliminating virus-infected cells, preventing autoimmunity, assisting in B-cell and plasma-cell production of antibodies, and detecting and eliminating cancer cells. The development of peptide/MHC class I tetramer staining of antigen-specific CD8 T cells1 and the more recent development of MHC class II tetramer staining of CD4 T cells2 by flow cytometry revolutionized our ability to study and understand the immunobiology of T cells. While extremely useful for determining the quantity and phenotype of antigen-specific T cells, flow cytometry does not allow for the detection of the spatial localization of antigen-specific T cells to other cells and structures in tissues, and current disaggregation techniques to extract the T cells needed for flow cytometry have limited effectiveness in non-lymphoid tissues3.
We and others have developed methods using peptide-loaded MHC class I and class II tetramer or multimer reagents to stain antigen-specific CD8 and CD4 T cells in tissues4,5,6,7,8,9,10,11,12,13. These IST methods allow for the determination of the location, abundance, and phenotype of antigen-specific CD8 and CD4 T cells in tissues and provide a means to detect of these cells relative to other cells and structures in the tissues. Our group has extensively used MHC-I tetramer staining to study human immunodeficiency virus (HIV)- and simian immunodeficiency virus (SIV)-specific CD8 T cells in lymphoid, genital, and rectal tissues to gain an understanding of HIV and SIV immunopathogenesis and to identify correlates of successful vaccination strategies14,15,16,17. In addition, we also developed a technique that combines IST with in situ hybridization (ISH) to localize and quantify virus-specific CD8 T cells and virus-infected cells in tissues and to determine the in vivo effector-to-target levels18,19.
Here, we describe a protocol using peptide-loaded MHC-I tetramers to stain antigen-specific CD8 T cells in fresh tissue sections, to counterstain tissues using IHC, and to quantify cells with specific phenotypes in specific tissue compartments. These procedures are the same as were used in our recent publication by Li et al., in which we determined the location, abundance, and phenotype of SIV-specific T cells in lymphoid tissue during chronic SIV infection in macaques20.
For this procedure, fresh tissues are sectioned and incubated overnight with peptide-loaded MHC-I tetramers conjugated to fluorescein thiocyanate molecules (FITC). They are then fixed in paraformaldehyde. After fixing the tissue, the signal from the MHC tetramers is amplified using rabbit anti-FITC antibodies and incubated with fluorescently tagged anti-rabbit IgG antibodies, which further amplify the signal from the bound tetramers. IHC is used in conjunction with IST to characterize antigen-specific T cells and surrounding cells. Antibodies that recognize epitopes on the surface of cells or in the extracellular space are included in the primary incubation with the tetramers. Antibodies that recognize intracellular epitopes require permeation of the cell wall prior to staining. The stained tissue sections are imaged using a confocal microscope and analyzed using confocal software. Labeled cells are quantified using confocal microscopy software or ImageJ. The described protocol can be used to stain essentially any antigen-specific CD8 T cell in any tissue for which MHC-I tetramers are available.

<table align="center" border="1" cellpadding="0" cellspacing="0" style="width:906px;" width="906">
	<tbody>
		<tr>
			<td>MHC-I monomer</td>
			<td>NIH tetramer core facility</td>
			<td></td>
			<td>Materials for MHC-tetramer preparation</td>
		</tr>
		<tr>
			<td>ExtrAvidin-FITC</td>
			<td>Sigma-Aldrich</td>
			<td>E2716</td>
			<td>Materials for MHC-tetramer preparation</td>
		</tr>
		<tr>
			<td>Normal goat serum</td>
			<td>Jackson Immunoresearch</td>
			<td>005-000-121</td>
			<td></td>
		</tr>
		<tr>
			<td>Low melt agarose</td>
			<td>Promega</td>
			<td>V3121</td>
			<td></td>
		</tr>
		<tr>
			<td>Heparin</td>
			<td>Sigma-Aldrich</td>
			<td>SLBL6391V</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td>T-6878</td>
			<td></td>
		</tr>
		<tr>
			<td>Urea</td>
			<td>J.T.Baker</td>
			<td>4204-05</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycerol/gelatin</td>
			<td>Sigma-Aldrich</td>
			<td>SLBH2672V</td>
			<td></td>
		</tr>
		<tr>
			<td>n-propyl gallate</td>
			<td>Sigma-Aldrich</td>
			<td>P3130</td>
			<td></td>
		</tr>
		<tr>
			<td>rat-a-h-CD8 (1:500)</td>
			<td>Acris</td>
			<td>0714</td>
			<td>Antibody unstable, use single use frozen aliquot</td>
		</tr>
		<tr>
			<td>m-a-h-CD20 (1:500)</td>
			<td>NOVOCASTRA</td>
			<td>6026819</td>
			<td></td>
		</tr>
		<tr>
			<td>m-a-h-Ki67 (1:500)</td>
			<td>Vector</td>
			<td>6022201</td>
			<td></td>
		</tr>
		<tr>
			<td>goat-a-m-A488 (1:2000)</td>
			<td>Jackson Immunoresearch</td>
			<td>124083</td>
			<td></td>
		</tr>
		<tr>
			<td>goat-a-rb-Cy3 (1:5000)</td>
			<td>Jackson Immunoresearch</td>
			<td>106232</td>
			<td></td>
		</tr>
		<tr>
			<td>goat-a-rat-Cy5 (1:5000)</td>
			<td>Jackson Immunoresearch</td>
			<td>118088</td>
			<td></td>
		</tr>
		<tr>
			<td>goat-a-h-IgM-Dylight649 (1:5000)</td>
			<td>Jackson Immunoresearch</td>
			<td>86579</td>
			<td></td>
		</tr>
		<tr>
			<td>Compresstome: VF-300 Microtome</td>
			<td>Precisionary Instruments, LLC</td>
			<td>1079</td>
			<td></td>
		</tr>
		<tr>
			<td>Quick Set Instant Adhesive</td>
			<td>Loctite</td>
			<td>46551</td>
			<td></td>
		</tr>
		<tr>
			<td>24-well flat bottomed tissue culture plates</td>
			<td>Falcon</td>
			<td>353226</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope slide</td>
			<td>Globe scienfitic Inc.</td>
			<td>#1321</td>
			<td></td>
		</tr>
		<tr>
			<td>Razor&#160; blade</td>
			<td>Ted Pella, Inc</td>
			<td>121-6</td>
			<td></td>
		</tr>
		<tr>
			<td>Feather Disposable Scalpel</td>
			<td>FEATHER SAFETY RAZOR CO. LTD.</td>
			<td>No. 21</td>
			<td></td>
		</tr>
		<tr>
			<td>Round paintbrush #2</td>
			<td>PRINCETON ART &#38; BRUSH CO.</td>
			<td>4350R</td>
			<td>Can trim as needed with razor</td>
		</tr>
		<tr>
			<td>Confocal Microscope</td>
			<td>Olympus</td>
			<td>FV1000</td>
			<td></td>
		</tr>
		<tr>
			<td>FV10-ASW_Viewer4.0</td>
			<td>Olympus</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

in situ mhc-tetramer staining and quantitative analysis to determine the location, abundance, and phenotype of antigen-specific cd8 t cells in tissues

T cells are critical to many immunological processes, including detecting and eliminating virus-infected cells, preventing autoimmunity, assisting in B-cell and plasma-cell production of antibodies, and detecting and eliminating cancer cells. The development of MHC-tetramer staining of antigen-specific T cells analyzed by flow cytometry has revolutionized our ability to study and understand the immunobiology of T cells. While extremely useful for determining the quantity and phenotype of antigen-specific T cells, flow cytometry cannot determine the spatial localization of antigen-specific T cells to other cells and structures in tissues, and current disaggregation techniques to extract the T cells needed for flow cytometry have limited effectiveness in non-lymphoid tissues. In situ MHC-tetramer staining (IST) is a technique to visualize T cells that are specific for antigens of interest in tissues. In combination with immunohistochemistry (IHC), IST can determine the abundance, location, and phenotype of antigen-specific CD8 and CD4 T cells in tissues. Here, we describe a protocol to stain and enumerate antigen-specific CD8 T cells, with specific phenotypes located within specific tissue compartments. These procedures are the same that we used in our recent publication by Li et al., entitled &#34;Simian Immunodeficiency Virus-Producing Cells in Follicles Are Partially Suppressed by CD8+ Cells In Vivo.&#34; The methods described are broadly applicable because they can be used to localize, phenotype, and quantify essentially any antigen-specific CD8 T cell for which MHC tetramers are available, in any tissue.

Figure 1 shows how to collect confocal images using a confocal microscope. Figure 2 demonstrates quantitative image analysis using ImageJ. Figures 3 and 4 show representative images of lymph node tissues from an SIV infected rhesus macaque stained with MHC tetramers, CD8 antibodies, and CD20 antibodies, and serve to demonstrate the specificity of the MHC-tetramer staining. Fi...

Watch this Scientific Journal Video about In Situ MHC-tetramer Staining and Quantitative Analysis to Determine the Location, Abundance, and Phenotype of Antigen-specific CD8 T Cells in Tissues at JoVE

In Situ MHC-tetramer Staining and Quantitative Analysis to Determine the Location, Abundance, and Phenotype of Antigen-specific CD8 T Cells in Tissues

Here, we describe a method that combines in situ MHC-tetramer staining with immunohistochemistry to determine localization, phenotype, and quantity of antigen-specific T cells in tissues. This protocol is used to determine the spatial and phenotypic characteristics of antigen-specific CD8 T cells relative to other cell type and structures in tissues.

In Situ MHC-tetramer Staining and Quantitative Analysis to Determine the Location, Abundance, and Phenotype of Antigen-specific CD8 T Cells in Tissues

T cells are critical to many immunological processes, including detecting and eliminating virus-infected cells, preventing autoimmunity, assisting in ...

The overall goal of this procedure is to determine the location, abundance and phenotype of antigen-specific CD8 positive T cells within tissues of interest. This method helps answer quick questions about CD8 T cells by providing a means to locate, quantify and phenotype virtually any antigen specific CD8 T cell and any tissue. The main advantage of this technique is that it allows determination of the spatial distribution of antigen specific CD8 positive T cells relative to other cells and structures within tissues of interest.Demonstrating the procedure with Shengbin Li will be Gwantwa Mwakalundwa. On the day one of the procedure, use a scalpel to cut the fresh tissue into approximately 0.5 x 0.5 centimeter pieces. Here, rhesus macaque spleen tissue is shown.Separately glue each tissue fragment into the middle of the top of a plunger and embed the samples in three to five milliliters of warm 4%low melting agarose in PBS. Label the plungers with the relevant tissue information. Then, place the samples in a chilled holder in an ice bucket.When the agar has solidified, turn on the microtome and set the thickness setting to 200 micrometers. After installing a new razor blade, insert the plungers into the microtome bath. Fill the microtome bath with 100 to 200 milliliters of freshly prepared PBS-H and add PBS-H ice cubes to maintain the temperature between zero to two degrees celsius.After obtaining 200 micrometer sections, use a paintbrush to remove the agar surrounding each section and transfer the samples into individual tissue chambers within individual wells of a 24 well tissue culture plate containing one milliliter of chilled PBS-H. When all of the samples have been acquired, incubate the tissue sections overnight in one milliliter of fit conjugated peptide loaded MHC class one tetramers, diluted in PBS-H supplemented with 2%normal goat serum at four degree celsius with rocking. The following morning, transfer each tissue chamber into individual wells of a new 24 well plate containing one milliliter of fresh chilled PBS-H for 20 minutes.After the second wash, fix the sections in one milliliter of fresh 4%paraformaldehyde for two hours at room temperature. Followed by two five minute washes in cold PBS-H. Transfer the sections into a new 24 well plate containing 0.01 molar urea and microwave the sections three times for about 10 seconds each time until the urea boils.To permeabilize and block the samples, incubate the sections in blocking solution containing PBS-H supplemented with a 0.3%triton x100 detergent and 2%normal goat serum on a rocker for one hour, at four degree celsius. At the end of the incubation, transfer the tissue chambers into individual wells of a new 24 well plate containing one milliliter of solution containing rabbit anti-fitc antibody, mouse antihuman CD antibody and rat antihuman CD3 antibody. Incubate the samples overnight at four degrees celsius with rocking.On day three, wash the sections three times in fresh PBS-H at four degree celsius for at least 20 minutes per wash and perform a final incubation with the appropriate fluorescence conjugated secondary antibodies for up to three days, protected from light. At the end of the tertiary antibody incubation, rinse the samples with three 20 minute washes in fresh PBS-H and use a paint brush to transfer the samples from each tissue chamber onto a glass microscope slide. Coat each section with mounting medium supplemented with a fluorophore preservative and cover the samples with a cover slip.Then, store the slides in a light protected slide container, at 20 degrees celsius. On the day of imaging, place the first slide onto the stage of a confocal microscope and select the appropriate lasers and filters for each fluorophore used to label the tissue sample. Using the 20x objective, sequentially obtain a z series at three micron intervals in each of the fluorophore channels, in multiple 800 x 800 pixel fields.Then, construct a montage of the collected fields and save each montage image with a name based on the corresponding tissue sample. In these representative images, a section stained with MHC class one tetramers loaded with an SIV peptide is compared to a section from the same tissue, stained with MHC class one tetramers loaded with an irrelevant peptide, demonstrating the specificity of the tetramer staining. In these images, the virus specific T cells stained with MHC class one tetramer loaded with SIV peptide, co-stains for CD8, a T cell subset marker but not CD20, a cell surface protein expressed on B cells.This montage was created for multiple confocal z series fields, that were used for the quantification of tetramer stained cells with specific phenotypes and different anatomical compartments on the lymph node. This magnified image highlights an area of the montage lymph node that contains a B cell follicle delineated by IGM staining. MHC class one tetramer stained cells, some of which co-expressed the T cell activation and proliferation marker, KI67 can be detected inside and outside of B cell follicle.This staining combination allows the determination of the activation and proliferation statuses of SIV specific CD8 positive T cells, as well as their localisation within secondary lymphoid tissues. Once mastered, this technique can be completed in approximately five days if it is performed properly. While attempting this procedure, it's important to remember that fresh tissue is critical for successful staining.Process the samples within 24 hours or less after harvesting, keeping them chilled until fixation. After watching this video, you should have a good understanding of how to perform a tetramer staining and immunohistochemistry to determine the location, abundance and phenotype of antigen specific CD8 positive T cells in tissues of interest. Don't forget that working with infectious agents can be extremely hazardous and that precautions to prevent exposure such as, wearing the appropriate personal protection equipment and limiting the use of sharps should always be taken while performing this procedure.

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Research

JoVE Journal

Immunology and Infection

12.1K Views.  University of Minnesota. The overall goal of this procedure is to determine the location, abundance and phenotype of antigen-specific CD8 positive T cells within tissues of interest. This method helps answer quick questions about CD8 T cells by providing a means to locate, quantify and phenotype virtually any antigen specific CD8 T cell and any tissue. The main advantage of this technique is that it allows determination of the spatial distribution of antigen specific CD8 positive T cells relative to other cells and s...

Video: In Situ MHC-tetramer Staining and Quantitative Analysis to Determine the Location, Abundance, and Phenotype of Antigen-specific CD8 T Cells in Tissues