We thank Paolo Dellabona and Giulia Casorati for scientific support and critical reading of the manuscript. We also thank the NIH Tetramer Core Facility for mouse CD1d tetramer. The study was funded by Fondazione Cariplo Grant 2018-0366 (to M.F.) and Italian Association for Cancer Research (AIRC) fellowship 2019-22604 (to G.D.).

Procedures described here were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) (no. 1048) at the San Raffaele Scientific Institute.
NOTE: All the procedures must be performed under sterile conditions. All the reagents used are listed in the Table of Materials.
1. Spleen processing
<ol>
	<li>Euthanize iV&#945;14-J&#945;18 mice by inhalation of CO2 according to the institutional policy. 
	NOTE: iV&#94...

<ol>
	<li>Bendelac, A., Savage, P. B., Teyton, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+biology+of+NKT+cells.">The biology of NKT cells.</a> Annual Review of Immunology. 25, 297-336 (2007).</li><li>Brennan, P. J., Brigl, M., Brenner, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invariant+natural+killer+T+cells:+an+innate+activation+scheme+linked+to+diverse+effector+functions.">Invariant natural killer T cells: an innate activation scheme linked to diverse effector functions.</a> Nature Reviews: Immunology. 13 (2), 101-117 (2013).</li><li>Pellicci, D. G., 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=A+natural+killer+T+(NKT)+cell+developmental+pathway+iInvolving+a+thymus-dependent+NK1.1(-)CD4(+)+CD1d-dependent+precursor+stage.">A natural killer T (NKT) cell developmental pathway iInvolving a thymus-dependent NK1.1(-)CD4(+) CD1d-dependent precursor stage.</a> Journal of Experimental Medicine. 195 (7), 835-844 (2002).</li><li>Benlagha, K., Kyin, T., Beavis, A., Teyton, L., Bendelac, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+thymic+precursor+to+the+NK+T+cell+lineage.">A thymic precursor to the NK T cell lineage.</a> Science. 296 (5567), 553-555 (2002).</li><li>Lee, Y. J., Holzapfel, K. L., Zhu, J., 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=Steady-state+production+of+IL-4+modulates+immunity+in+mouse+strains+and+is+determined+by+lineage+diversity+of+iNKT+cells.">Steady-state production of IL-4 modulates immunity in mouse strains and is determined by lineage diversity of iNKT cells.</a> Nature Immunology. 14 (11), 1146-1154 (2013).</li><li>Griewank, 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=Homotypic+interactions+mediated+by+Slamf1+and+Slamf6+receptors+control+NKT+cell+lineage+development.">Homotypic interactions mediated by Slamf1 and Slamf6 receptors control NKT cell lineage development.</a> Immunity. 27 (5), 751-762 (2007).</li><li>Cortesi, 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=Bimodal+CD40/Fas-Dependent+Crosstalk+between+iNKT+Cells+and+Tumor-Associated+Macrophages+Impairs+Prostate+Cancer+Progression.">Bimodal CD40/Fas-Dependent Crosstalk between iNKT Cells and Tumor-Associated Macrophages Impairs Prostate Cancer Progression.</a> Cell Reports. 22 (11), 3006-3020 (2018).</li><li>Heczey, 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=Invariant+NKT+cells+with+chimeric+antigen+receptor+provide+a+novel+platform+for+safe+and+effective+cancer+immunotherapy.">Invariant NKT cells with chimeric antigen receptor provide a novel platform for safe and effective cancer immunotherapy.</a> Blood. 124 (18), 2824-2833 (2014).</li><li>Liu, 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=A+modified+alpha-galactosyl+ceramide+for+staining+and+stimulating+natural+killer+T+cells.">A modified alpha-galactosyl ceramide for staining and stimulating natural killer T cells.</a> Journal of Immunological Methods. 312 (1-2), 34-39 (2006).</li><li>Chiba, 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=Rapid+and+reliable+generation+of+invariant+natural+killer+T-cell+lines+in+vitro.">Rapid and reliable generation of invariant natural killer T-cell lines in vitro.</a> Immunology. 128 (3), 324-333 (2009).</li><li>Crowe, N. 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=Differential+antitumor+immunity+mediated+by+NKT+cell+subsets+in+vivo.">Differential antitumor immunity mediated by NKT cell subsets in vivo.</a> Journal of Experimental Medicine. 202 (9), 1279-1288 (2005).</li><li>de Lalla, 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=Production+of+profibrotic+cytokines+by+invariant+NKT+cells+characterizes+cirrhosis+progression+in+chronic+viral+hepatitis.">Production of profibrotic cytokines by invariant NKT cells characterizes cirrhosis progression in chronic viral hepatitis.</a> Journal of Immunology. 173 (2), 1417-1425 (2004).</li><li>Tian, G., 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=CD62L++NKT+cells+have+prolonged+persistence+and+antitumor+activity+in+vivo.">CD62L+ NKT cells have prolonged persistence and antitumor activity in vivo.</a> Journal of Clinical Investigation. 126 (6), 2341-2355 (2016).</li><li>Gaya, 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=Initiation+of+Antiviral+B+Cell+Immunity+Relies+on+Innate+Signals+from+Spatially+Positioned+NKT+Cells.">Initiation of Antiviral B Cell Immunity Relies on Innate Signals from Spatially Positioned NKT Cells.</a> Cell. 172 (3), 517-533 (2018).</li><li>Rotolo, 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=Enhanced+Anti-lymphoma+Activity+of+CAR19-iNKT+Cells+Underpinned+by+Dual+CD19+and+CD1d+Targeting.">Enhanced Anti-lymphoma Activity of CAR19-iNKT Cells Underpinned by Dual CD19 and CD1d Targeting.</a> Cancer Cell. 34 (4), 596-610 (2018).</li><li>Schneidawind, 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=Third-party+CD4++invariant+natural+killer+T+cells+protect+from+murine+GVHD+lethality.">Third-party CD4+ invariant natural killer T cells protect from murine GVHD lethality.</a> Blood. 125 (22), 3491-3500 (2015).</li><li>Schneidawind, 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=CD4++invariant+natural+killer+T+cells+protect+from+murine+GVHD+lethality+through+expansion+of+donor+CD4+CD25+FoxP3++regulatory+T+cells.">CD4+ invariant natural killer T cells protect from murine GVHD lethality through expansion of donor CD4+CD25+FoxP3+ regulatory T cells.</a> Blood. 124 (22), 3320-3328 (2014).</li><li>Schneidawind, D., Pierini, A., Negrin, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulatory+T+cells+and+natural+killer+T+cells+for+modulation+of+GVHD+following+allogeneic+hematopoietic+cell+transplantation.">Regulatory T cells and natural killer T cells for modulation of GVHD following allogeneic hematopoietic cell transplantation.</a> Blood. 122 (18), 3116-3121 (2013).</li><li>Leveson-Gower, D. 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=Low+doses+of+natural+killer+T+cells+provide+protection+from+acute+graft-versus-host+disease+via+an+IL-4-dependent+mechanism.">Low doses of natural killer T cells provide protection from acute graft-versus-host disease via an IL-4-dependent mechanism.</a> Blood. 117 (11), 3220-3229 (2011).</li><li>Coman, 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=Human+CD4-+invariant+NKT+lymphocytes+regulate+graft+versus+host+disease.">Human CD4- invariant NKT lymphocytes regulate graft versus host disease.</a> Oncoimmunology. 7 (11), 1470735 (2018).</li><li>Xu, X., 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=NKT+Cells+Coexpressing+a+GD2-Specific+Chimeric+Antigen+Receptor+and+IL15+Show+Enhanced+In+vivo+Persistence+and+Antitumor+Activity+against+Neuroblastoma.">NKT Cells Coexpressing a GD2-Specific Chimeric Antigen Receptor and IL15 Show Enhanced In vivo Persistence and Antitumor Activity against Neuroblastoma.</a> Clinical Cancer Research. 25 (23), 7126-7138 (2019).</li><li>Heczey, 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=Anti-GD2+CAR-NKT+cells+in+patients+with+relapsed+or+refractory+neuroblastoma:+an+interim+analysis.">Anti-GD2 CAR-NKT cells in patients with relapsed or refractory neuroblastoma: an interim analysis.</a> Nature Medicine. 26 (11), 1686-1690 (2020).</li><li>Exley, M. 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=Adoptive+Transfer+of+Invariant+NKT+Cells+as+Immunotherapy+for+Advanced+Melanoma:+A+Phase+I+Clinical+Trial.">Adoptive Transfer of Invariant NKT Cells as Immunotherapy for Advanced Melanoma: A Phase I Clinical Trial.</a> Clinical Cancer Research. 23 (14), 3510-3519 (2017).</li><li>Wolf, B. J., Choi, J. E., Exley, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+Approaches+to+Exploiting+Invariant+NKT+Cells+in+Cancer+Immunotherapy.">Novel Approaches to Exploiting Invariant NKT Cells in Cancer Immunotherapy.</a> Frontiers in Immunology. 9, 384 (2018).</li></ol>

The authors have nothing to disclose.

Here we show a reproducible and feasible protocol to obtain millions of ready-to-use iNKT cells. Due to the paucity of these cells in vivo, a method to expand them was highly needed. The protocol we propose requires neither a particular instrumentation nor a high number of mice. We exploited iV&#945;14-J&#945;18 transgenic mice on purpose to reduce the number of mice needed for the procedure.
Another successful protocol for iNKT cell expansion from iV&#945;14-J&#945;18 transgenic mice is avail...

Invariant Natural killer T cells (iNKT cells) are innate-like T lymphocytes that express a semi-invariant &#945;&#946; T cell receptor (TCR), formed in mice by an invariant V&#945;14-J&#945;18 chain paired with a limited set of diverse V&#946; chains1, which is specific for lipid antigens presented by the MHC class I-related molecule CD1d2. iNKT cells undergo an agonist selection program resulting in the acquisition of an activated/innate effector phenotype already in the thymus, which occurs through several maturation stages3,4, producing a CD4+ and a CD4- subset. Through this program, iNKT cells acquire distinct T helper (TH) effector phenotypes, namely TH1 (iNKT1), TH2 (iNKT2) and TH17 (iNKT17), identifiable by the expression of the transcription factors T-bet, GATA3, PLZF, and ROR&#947;t, respectively5. iNKT cells recognize a range of microbial lipids but are also self-reactive against endogenous lipids that are upregulated in the context of pathological situations of cell stress and tissue damage, such as cancer and autoimmunity2. Upon activation, iNKT cells modulate the functions of other innate and adaptive immune effector cells via direct contact and cytokine production2.
The investigations of iNKT cells have been facilitated by mouse models, including CD1d-deficient or J&#945;18-deficient mice, and by the production of antigen-loaded CD1d tetramers plus the generation of monoclonal antibodies (mAbs) specific for the human semi-invariant TCR. However, the generation of primary mouse iNKT cell line has proved difficult. To better characterize the antitumor functions of iNKT cells and to utilize them for adoptive cell therapy, we set up a protocol to purify and expand splenic iNKT cells of iV&#945;14-J&#945;18 transgenic mice (iV&#945;14Tg)6, in which iNKT cells are 30 times more frequent than in wild type mice.
Expanded iNKT cells can be exploited for in vitro assays, and in vivo upon transfer back into mice. In this setting, for example, we have shown their potent anti-tumor effects7. Moreover, in vitro expanded iNKT cells are amenable to functional modification via gene transfer or editing prior to their injection in vivo8, allowing insightful functional analysis of molecular pathways, as well as paving the way for advanced cell therapies.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Ammonium-Chloride-Potassium (ACK) solution</td>
			<td>in house</td>
			<td></td>
			<td>0.15M NH4Cl, 10mM KHCO3, 0.1mM EDTA, pH 7.2-7.4</td>
		</tr>
		<tr>
			<td>anti-FITC Microbeads</td>
			<td>Miltenyi Biotec</td>
			<td>130-048-701</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-PE Microbeads</td>
			<td>Miltenyi Biotec</td>
			<td>130-048-801</td>
			<td></td>
		</tr>
		<tr>
			<td>Brefeldin A</td>
			<td>Sigma</td>
			<td>B6542</td>
			<td></td>
		</tr>
		<tr>
			<td>CD19 -FITC</td>
			<td>Biolegend</td>
			<td>115506</td>
			<td>clone 6D5</td>
		</tr>
		<tr>
			<td>CD1d-tetramer -PE</td>
			<td>NIH tetramer core facility</td>
			<td></td>
			<td>mouse PBS57-Cd1d-tetramers</td>
		</tr>
		<tr>
			<td>CD4 -PeCy7</td>
			<td>Biolegend</td>
			<td>100528</td>
			<td>clone RM4-5</td>
		</tr>
		<tr>
			<td>Fc blocker</td>
			<td>BD Bioscience</td>
			<td>553142</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Euroclone</td>
			<td>ECS0186L</td>
			<td>heat-inactivated and filtered .22 before use</td>
		</tr>
		<tr>
			<td>FOXP3 Transcription factor staining buffer</td>
			<td>eBioscience</td>
			<td>00-5523-00</td>
			<td></td>
		</tr>
		<tr>
			<td>H2 (IAb) -FITC</td>
			<td>Biolegend</td>
			<td>114406</td>
			<td>clone AF6-120.1</td>
		</tr>
		<tr>
			<td>hrIL-2</td>
			<td>Chiron Corp</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ionomycin</td>
			<td>Sigma</td>
			<td>I0634</td>
			<td></td>
		</tr>
		<tr>
			<td>LD Columns</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-901</td>
			<td></td>
		</tr>
		<tr>
			<td>LS Columns</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-401</td>
			<td></td>
		</tr>
		<tr>
			<td>MACS buffer (MB)</td>
			<td>in house</td>
			<td></td>
			<td>0.5% Bovine Serum Albumin (BSA; Sigma-Aldrich) and 2Mm EDTA</td>
		</tr>
		<tr>
			<td>MS Columns</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-201</td>
			<td></td>
		</tr>
		<tr>
			<td>Non-essential amino acids</td>
			<td>Gibco</td>
			<td>11140-035</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin and streptomycin (Pen-Strep)</td>
			<td>Lonza</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>PermWash</td>
			<td>BD Bioscience</td>
			<td>51-2091KZ</td>
			<td></td>
		</tr>
		<tr>
			<td>PFA</td>
			<td>Sigma</td>
			<td>P6148</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS)</td>
			<td>EuroClone</td>
			<td>ECB4004L</td>
			<td></td>
		</tr>
		<tr>
			<td>PMA</td>
			<td>Sigma</td>
			<td>P1585</td>
			<td></td>
		</tr>
		<tr>
			<td>Pre-Separation Filters (30 &#181;m)</td>
			<td>Miltenyi Biotec</td>
			<td>130-041-407</td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinat Mouse IL-7</td>
			<td>R&#38;D System</td>
			<td>407-ML-025</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI 1640 with glutamax</td>
			<td>Gibco</td>
			<td>61870-010</td>
			<td></td>
		</tr>
		<tr>
			<td>sodium pyruvate</td>
			<td>Gibco</td>
			<td>11360-039</td>
			<td></td>
		</tr>
		<tr>
			<td>TCR&#946; -APC</td>
			<td>Biolegend</td>
			<td>109212</td>
			<td>clone H57-597</td>
		</tr>
		<tr>
			<td>&#945;CD3CD28 mouse T activator Dynabeads</td>
			<td>Gibco</td>
			<td>11452D</td>
			<td></td>
		</tr>
		<tr>
			<td>&#946;-mercaptoethanol</td>
			<td>Gibco</td>
			<td>31350010</td>
			<td></td>
		</tr>
	</tbody>
</table>

purification and expansion of mouse invariant natural killer t cells for in vitro and in vivo studies

Invariant Natural Killer T (iNKT) cells are innate-like T Lymphocytes expressing a conserved semi-invariant T cell receptor (TCR) specific for self or microbial lipid antigens presented by the non-polymorphic MHC class I-related molecule CD1d. Preclinical and clinical studies support a role for iNKT cells in cancer, autoimmunity and infectious diseases. iNKT cells are very conserved throughout species and their investigation has been facilitated by mouse models, including CD1d-deficient or iNKT-deficient mice, and the possibility to unequivocally detect them in mice and men with CD1d tetramers or mAbs specific for the semi-invariant TCR. However, iNKT cells are rare and they need to be expanded to reach manageable numbers for any study. Because the generation of primary mouse iNKT cell line in vitro has proven difficult, we have set up a robust protocol to purify and expand splenic iNKT cells from the iV&#945;14-J&#945;18 transgenic mice (iV&#945;14Tg), in which iNKT cells are 30 times more frequent. We show here that primary splenic iV&#945;14Tg iNKT cells can be enriched through an immunomagnetic separation process, yielding about 95-98% pure iNKT cells. The purified iNKT cells are stimulated by anti-CD3/CD28 beads plus IL-2 and IL-7, resulting in 30-fold expansion by day +14 of the culture with 85-99% purity. The expanded iNKT cells can be easily genetically manipulated, providing an invaluable tool to dissect mechanisms of activation and function in vitro and, more importantly, also upon adoptive transfer in vivo.

The protocol described in this manuscript enables to enrich iNKT cells from the spleen of iVa14-Ja18 transgenic mice through an immunomagnetic separation process summarized in Figure 1A. Total spleen T cells are first negatively selected by depleting B cells and monocytes, followed by iNKT cell positive immunomagnetic sorting with PBS-57 lipid antigen loaded CD1d tetramers, that enable to specifically stain only iNKT cells. This protocol yields about 2 x 106 of 95-98% pure iNKT ce...

Watch this Scientific Journal Video about Purification and Expansion of Mouse Invariant Natural Killer T Cells for in vitro and in vivo Studies at JoVE.com

Purification and Expansion of Mouse Invariant Natural Killer T Cells for in vitro and in vivo Studies

We describe a rapid and robust protocol to enrich invariant natural killer T (iNKT) cells from mouse spleen and expand them in vitro to suitable numbers for in vitro and in vivo studies.

Invariant Natural Killer T (iNKT) cells are innate-like T Lymphocytes expressing a conserved semi-invariant T cell receptor (TCR) specific for self or ...

This protocol enables the purification of INK T-cells, which are very rare, and allows a 30-fold expansion in their number. The purification can be performed in one day and produce a large number of ready-to-use INK T-cells for in vivo and in vitro studies in two weeks. Demonstrating the procedure will be Gloria Delfanti, a post-doc in the lab.After dissecting the mouse spleen, smash it through a 70 nanometer cell strainer to obtain a single cell suspension in 10 milliliters of PBS with 2%FBS. Centrifuge at 300 times G for five minutes. Remove the supernatant and resuspend the cell pellet with one milliliter of sterile ammonium chloride potassium lysine buffer.Incubate the cells for three minutes at room temperature, then block with five milliliters of PBS with 2%FBS. Centrifuge at 300 times G for five minutes. After removing the supernatant, resuspend the cell pellet in three milliliters of PBS with 2%FBS and remove fat residues by pipetting.For the enrichment steps, keep the cells cold and use solutions pre-cooled at four degrees Celsius and then kept on ice. Centrifuge at 300 times G for five minutes. Resuspend all the cells in the appropriate amount of PBS with 2%FPS and Fc blocker and incubate for 15 minutes at room temperature.Wash with one to two milliliters of MACS separation buffer per 10 million cells and centrifuge at 300 times G for 10 minutes. After removing the supernatant, stain the cells with CD19-FITC and H2-IAb-FITC and incubate for 15 minutes in the dark at four to eight degrees Celsius. Wash cells by adding one to two milliliters of MACS buffer per 10 million cells and centrifuge at 300 times G for 10 minutes.Remove supernatant and resuspend the cell pellet in 90 microliters of MACS buffer per 10 million cells. Add 10 microliters of anti-FITC microbeads per 10 million cells. Mix well and incubate for 15 minutes in the dark at four to eight degrees Celsius.Wash the cells by adding one to two milliliters of MACS buffer per 10 million cells and centrifuge at 300 times G for 10 minutes. Remove the supernatant and resuspend up to 125 million cells in 500 microliters of MACS buffer. Place an LD column in the magnetic field of the MACS separator.To avoid clogging, apply a pre-separation filter on the LD column and rinse it with two milliliters of MACS buffer. Apply the cell suspension onto the filter and collect the unlabeled cells that pass through the column. Wash the empty column reservoir three times with one milliliter of MACS buffer.Collect the T-cell enriched effluent and count the cells, keeping 50 microliters for FACS analysis. After centrifuging at 300 times G for five minutes, remove the supernatant and stain the cells with CD1d tetramer-PE. Mix well and incubate for 30 minutes in the dark on ice.Wash the cells by adding one to two milliliters of MACS buffer per 10 million cells. After centrifugation at 300 times G for 10 minutes, remove the supernatant and resuspend the cell pellet in 80 microliters of MACS buffer per 10 million cells. Add 20 microliters of anti-PE microbeads per 10 million cells.Mix well and incubate for 15 minutes in the dark at four to eight degrees Celsius. Wash cells by adding one to two milliliters of MACS buffer per 10 million cells and centrifuge at 300 times G for 10 minutes. Remove the supernatant and resuspend up to 100 million cells in 500 microliters of MACS buffer.According to the cell count, place the LS or MS column in the magnetic field of the MACS separator and rinse the column with MACS buffer. Apply the cell suspension onto the column, collect unlabeled cells that pass through and wash the column three times as described previously. This is the negative fraction.Remove the column from the magnetic field and place it on a new collection tube. Pipette MACS buffer onto the column and push the provided plunger into the column to flush out the positive fraction enriched in INK T-cells. To further increase INK T-cell recovery, centrifuge the negative fraction at 300 times G for 10 minutes and repeat previous steps with a new LS or MS column.Pull the positive fractions and determine cell count. Keep 50 microliters of both positive and negative fractions for FACS analysis to check the purity. To activate INK T cells at a one-to-one ratio, transfer the appropriate volume of anti-CD3 and CD28 magnetic beads to a tube and at an equal volume of PBS, then vortex for five seconds.Place the tube on a magnet for one minute and discard the supernatant. Remove the tube from the magnet and resuspend the washed magnetic beads in the proper volume of RPMI. Centrifuge purified INK T-cells at 300 times G for five minutes and mix them with mouse T-activator anti-CD3 or CD28 magnetic beads.Plate one milliliter of the cell suspension, anti-CD23 and CD28 magnetic beads in a 48-well plate with 20 units per milliliter IL-2, then incubate at 37 degrees Celsius. After five days, add 10 nanograms per milliliter IL-7. Split the cells in half when they reach 80 to 90%confluence, always adding 20 units per milliliter IL-2 and 10 nanograms per milliliter IL-7.Under these conditions, INK T-cells can be expanded for up to 15 days. Using this protocol, INK T-cells are enriched from the spleen of transgenic mice through an immunomagnetic separation process. After enrichment, the cells can be expanded with anti-CD3 and CD28 beads, resulting in a 30-fold expansion on average by day 14 of the culture.The strong activation with anti-CD3 and anti-CD beads induced the downregulation of the IMK T-cell TCR expression on the cell surface and a double negative population appeared. The majority of expanded INK T-cells are CD4 negative. Characterization of the lineage-specific transcription factors PLZF and ROR gamma T made it possible to identify the NKT1, NKT2, and NKT17 phenotypes on enriched INK T-cells at day zero and 14.The enriched INK T-cells show a T80-like effector phenotype, which is conserved after 14 days of expansion as confirmed by the secretion of both interferon gamma and IL-4 after PMA and ionomycin stimulation. During the purification steps, remember to work fast with pre-cooled solutions and get rid of any fat residues that may be seen while pipetting. Expanded INK T-cells can be exploited for in vitro assays and in vivo transfers into mice, even after functional modifications via gene transfer or editing.In vitro expansion of INK T-cells overcomes the limitation given by the paucity, making them exploitable in preclinical studies in the fields of tumor immune surveillance, infectious diseases, and auto-immunity.

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Research

JoVE Journal

Immunology and Infection

3.8K visualizações.  IRCCS San Raffaele Scientific Institute. Este protocolo permite a purificação de células T ink, que são muito raras, e permite uma expansão de 30 vezes em seu número. A purificação pode ser realizada em um dia e produzir um grande número de células T de tinta prontas para uso para estudos in vivo e in vitro em duas semanas. Demonstrando o procedimento será Gloria Delfanti, uma pós-doutora no laboratório.Depois de dissecar o baço do mouse, esmague-o através de um coador de células de 70 nanômetros para obter u...