Name: an efficient and simple method to establish nk and t cell lines from patients with chronic active epstein-barr virus infection
Uploaded: 2018-03-30T13:00:00
Description: Watch this Scientific Journal Video about An Efficient and Simple Method to Establish NK and T Cell Lines from Patients with Chronic Active Epstein-Barr Virus Infection at JoVE.com

This work was supported by the Key Projects of Chinese Academy of Sciences (KFZD-SW-205), Strategic Biological Resources Technology Support System of Chinese Academy of Sciences (CZBZX-1 and ZSSB-004), and by Grants from National Science Foundation of China (81401640) and&#160; Shanghai Natural Science Fund (14ZR1434800).

This study was approved by the Ethics Committee of the Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and the protocol follows the institutional guidelines for human welfare.
NOTE: See Figure 1 for a schematic of the workflow.
1. Isolation of PBMC from CAEBV Patients
<ol>
	<li>Purify primary PBMC from 2 mL of whole blood of CAEBV patients by gradient (e.g., Ficoll-plaque) centrifugation followin...

<ol>
	<li>Cohen, J. I. <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+infection.">Epstein-Barr virus infection.</a> N Engl J Med. 343 (7), 481-492 (2000).</li><li>Cohen, J. I., Kimura, H., Nakamura, S., Ko, Y. H., Jaffe, E. S. <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-associated+lymphoproliferative+disease+in+non-immunocompromised+hosts:+a+status+report+and+summary+of+an+international+meeting,+8-9+September+2008.">Epstein-Barr virus-associated lymphoproliferative disease in non-immunocompromised hosts: a status report and summary of an international meeting, 8-9 September 2008.</a> Ann Oncol. 20 (9), 1472-1482 (2009).</li><li>Oshimi, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progress+in+understanding+and+managing+natural+killer-cell+malignancies.">Progress in understanding and managing natural killer-cell malignancies.</a> Br J Haematol. 139 (4), 532-544 (2007).</li><li>Kawa, 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=Mosquito+allergy+and+Epstein-Barr+virus-associated+T/natural+killer-cell+lymphoproliferative+disease.">Mosquito allergy and Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disease.</a> Blood. 98 (10), 3173-3174 (2001).</li><li>Kimura, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogenesis+of+chronic+active+Epstein-Barr+virus+infection:+is+this+an+infectious+disease,+lymphoproliferative+disorder,+or+immunodeficiency?.">Pathogenesis of chronic active Epstein-Barr virus infection: is this an infectious disease, lymphoproliferative disorder, or immunodeficiency?.</a> Rev Med Virol. 16 (4), 251-261 (2006).</li><li>Kimura, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+and+virologic+characteristics+of+chronic+active+Epstein-Barr+virus+infection.">Clinical and virologic characteristics of chronic active Epstein-Barr virus infection.</a> Blood. 98 (2), 280-286 (2001).</li><li>Ohshima, 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=Proposed+categorization+of+pathological+states+of+EBV-associated+T/natural+killer-cell+lymphoproliferative+disorder+(LPD)+in+children+and+young+adults:+overlap+with+chronic+active+EBV+infection+and+infantile+fulminant+EBV+T-LPD.">Proposed categorization of pathological states of EBV-associated T/natural killer-cell lymphoproliferative disorder (LPD) in children and young adults: overlap with chronic active EBV infection and infantile fulminant EBV T-LPD.</a> Pathol Int. 58 (4), 209-217 (2008).</li><li>Okano, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Overview+and+problematic+standpoints+of+severe+chronic+active+Epstein-Barr+virus+infection+syndrome.">Overview and problematic standpoints of severe chronic active Epstein-Barr virus infection syndrome.</a> Crit Rev Oncol Hematol. 44 (3), 273-282 (2002).</li><li>Straus, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+chronic+mononucleosis+syndrome.">The chronic mononucleosis syndrome.</a> J Infect Dis. 157 (3), 405-412 (1988).</li><li>Jones, J. 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=T-cell+lymphomas+containing+Epstein-Barr+viral+DNA+in+patients+with+chronic+Epstein-Barr+virus+infections.">T-cell lymphomas containing Epstein-Barr viral DNA in patients with chronic Epstein-Barr virus infections.</a> N Engl J Med. 318 (12), 733-741 (1988).</li><li>Kikuta, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epstein-Barr+virus+genome-positive+T+lymphocytes+in+a+boy+with+chronic+active+EBV+infection+associated+with+Kawasaki-like+disease.">Epstein-Barr virus genome-positive T lymphocytes in a boy with chronic active EBV infection associated with Kawasaki-like disease.</a> Nature. 333 (6172), 455-457 (1988).</li><li>Nagata, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+novel+natural+killer+(NK)-cell+and+gammadelta+T-cell+lines+established+from+primary+lesions+of+nasal+T/NK-cell+lymphomas+associated+with+the+Epstein-Barr+virus.">Characterization of novel natural killer (NK)-cell and gammadelta T-cell lines established from primary lesions of nasal T/NK-cell lymphomas associated with the Epstein-Barr virus.</a> Blood. 97 (3), 708-713 (2001).</li><li>Nagata, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presence+of+natural+killer-cell+clones+with+variable+proliferative+capacity+in+chronic+active+Epstein-Barr+virus+infection.">Presence of natural killer-cell clones with variable proliferative capacity in chronic active Epstein-Barr virus infection.</a> Pathol Int. 51 (10), 778-785 (2001).</li><li>Tabata, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydroa+vacciniforme-like+lymphomatoid+papulosis+in+a+Japanese+child:+a+new+subset.">Hydroa vacciniforme-like lymphomatoid papulosis in a Japanese child: a new subset.</a> J Am Acad Dermatol. 32 (2 Pt 2), 378-381 (1995).</li><li>Tsuchiyama, 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=Characterization+of+a+novel+human+natural+killer-cell+line+(NK-YS)+established+from+natural+killer+cell+lymphoma/leukemia+associated+with+Epstein-Barr+virus+infection.">Characterization of a novel human natural killer-cell line (NK-YS) established from natural killer cell lymphoma/leukemia associated with Epstein-Barr virus infection.</a> Blood. 92 (4), 1374-1383 (1998).</li><li>Tsuge, I., 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=Characterization+of+Epstein-Barr+virus+(EBV)-infected+natural+killer+(NK)+cell+proliferation+in+patients+with+severe+mosquito+allergy;+establishment+of+an+IL-2-dependent+NK-like+cell+line.">Characterization of Epstein-Barr virus (EBV)-infected natural killer (NK) cell proliferation in patients with severe mosquito allergy; establishment of an IL-2-dependent NK-like cell line.</a> Clin Exp Immunol. 115 (3), 385-392 (1999).</li><li>Zhang, 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=Common+cytological+and+cytogenetic+features+of+Epstein-Barr+virus+(EBV)-positive+natural+killer+(NK)+cells+and+cell+lines+derived+from+patients+with+nasal+T/NK-cell+lymphomas,+chronic+active+EBV+infection+and+hydroa+vacciniforme-like+eruptions.">Common cytological and cytogenetic features of Epstein-Barr virus (EBV)-positive natural killer (NK) cells and cell lines derived from patients with nasal T/NK-cell lymphomas, chronic active EBV infection and hydroa vacciniforme-like eruptions.</a> Br J Haematol. 121 (5), 805-814 (2003).</li><li>Oyoshi, M. 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=Preferential+expansion+of+Vgamma9-JgammaP/Vdelta2-Jdelta3+gammadelta+T+cells+in+nasal+T-cell+lymphoma+and+chronic+active+Epstein-Barr+virus+infection.">Preferential expansion of Vgamma9-JgammaP/Vdelta2-Jdelta3 gammadelta T cells in nasal T-cell lymphoma and chronic active Epstein-Barr virus infection.</a> Am J Pathol. 162 (5), 1629-1638 (2003).</li><li>Imadome, 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=Novel+mouse+xenograft+models+reveal+a+critical+role+of+CD4++T+cells+in+the+proliferation+of+EBV-infected+T+and+NK+cells.">Novel mouse xenograft models reveal a critical role of CD4+ T cells in the proliferation of EBV-infected T and NK cells.</a> PLoS Pathog. 7 (10), e1002326 (2011).</li><li>Shibuya, A., Nagayoshi, K., Nakamura, K., Nakauchi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lymphokine+requirement+for+the+generation+of+natural+killer+cells+from+CD34++hematopoietic+progenitor+cells.">Lymphokine requirement for the generation of natural killer cells from CD34+ hematopoietic progenitor cells.</a> Blood. 85 (12), 3538-3546 (1995).</li><li>Spits, H., Yssel, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cloning+of+Human+T+and+Natural+Killer+Cells.">Cloning of Human T and Natural Killer Cells.</a> Methods. 9 (3), 416-421 (1996).</li><li>Liu, X., Xu, C., Duan, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Simple+Red+Blood+Cell+Lysis+Method+for+the+Establishment+of+B+Lymphoblastoid+Cell+Lines.">A Simple Red Blood Cell Lysis Method for the Establishment of B Lymphoblastoid Cell Lines.</a> J Vis Exp. (119), (2017).</li><li>Kawabe, 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=Application+of+flow+cytometric+in+situ+hybridization+assay+to+Epstein-Barr+virus-associated+T/natural+killer+cell+lymphoproliferative+diseases.">Application of flow cytometric in situ hybridization assay to Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases.</a> Cancer Sci. 103 (8), 1481-1488 (2012).</li></ol>

In this protocol, a novel technique for establishing NK/T cell lines from whole blood of CAEBV patients has been developed. Compared with the existing methods, the major advantage of this method is its simplicity and its requirement of only a small volume of blood, while it exhibits a high success rate and good conditions of cell viability. Furthermore, NK/T cell lines can be established by culturing PBMC without determining the cell types the EBV latently infected in advance, as the determination would consume more bloo...

Epstein-Barr virus (EBV) is ubiquitous and infects not only B cells, but also T and natural killer (NK) cells, which causes a number of EBV-associated NK/T lymphoproliferative diseases (LPD) and lymphoma/leukemia, such as EBV-associated hemophagocytic lymphohistiocytosis, hydroa vacciniforme-like lymphoma, extranodal NK/T-cell lymphoma, nasal type and aggressive NK cell leukemia1,2,3. Among these is severe chronic active EBV (SCAEBV) disease, which is incident mainly in East Asia, and which is now considered to be a LPD caused by clonal expansion of EBV-infected T or NK cells4,5,6,7, but without the apparent immunodeficiency present in infectious mononucleosis (IM)-like symptoms including fever, hepatosplenomegaly, lymphadenopathy, and liver dysfunction persistently or recurrently, as well as high EBV-DNA load in the peripheral blood8,9. Patients with CAEBV have a poor prognosis10,11, and its pathogenesis and the role of the EBV is unclear. Therefore, cell lines derived from EBV-associated NK/T lymphoproliferative diseases and lymphomas are very helpful as cell models for clarifying the mechanism of EBV induced NK or T cell proliferation and its relationship with high incidence of leukemia or lymphoma. 
To date, several cell lines have been established with different techniques12,13,14,15,16. A human NK cell line, NK-YS, was established from NK cell lymphoma/leukemia, by co-culturing with a mouse stromal cell line as feeder, and in the presence of rhIL-2 at a concentration of 20U per mL15. KAI3 was another NK cell line established from patients with a severe mosquito allergy or SCAEBV with autologous lymphoblastoid cell line (LCL), B cells transformed by EBV, as feeder cells and addition of rhIL-2 at 100U/mL16. SNK6 and SNT8 were derived from tumor tissues of nasal NK/T cell lymphoma patients by adding high-dose of rhIL-2 (700U/mL)12. With similar technique, the SNK-1 cell was from CAEBV patients, cultured from PBMC by removing T cells and adding 700U/mL of rhIL-213,17. SNT13 and SNT15 were established by removing CD4+ and CD8+ cells18. So far, other T cell and NK cell lines from EBV-NK/T LPD patients were all developed with this method19.
The disadvantages of the existing methods mentioned above include the employment of feeder cells, the requirement of a high-dose of IL-2, the utilization of as much as 10 mL whole blood, or the purification of NK/T cells, which is very challenging in the clinic due to the necessity of verifying which types of cell that EBV latently infects before beginning to culture. As CAEBV mainly occurs in children in Asia, 10 mL blood is not easy to acquire in all regions. In this study, we developed a new simple method with a high success rate to establish NK and/or T cell lines by culturing PBMC from CAEBV patients using a low-dose of rhIL2 and a volume of 2 mL of whole blood without feeder cells. The results of this method have proven its high efficiency and time saving.

<table>
	<tbody>
		<tr>
			<td>Hu HLA-DR FITC</td>
			<td>BD</td>
			<td>560944</td>
			<td>antibody for FACS</td>
		</tr>
		<tr>
			<td>Hu CD4 FITC</td>
			<td>BD</td>
			<td>555346</td>
			<td>antibody for FACS</td>
		</tr>
		<tr>
			<td>Hu/NHP CD8 PE</td>
			<td>BD</td>
			<td>557086</td>
			<td>antibody for FACS</td>
		</tr>
		<tr>
			<td>Hu CD3 PE</td>
			<td>BD</td>
			<td>555340</td>
			<td>antibody for FACS</td>
		</tr>
		<tr>
			<td>Hu CD16 FITC 3G8</td>
			<td>BD</td>
			<td>555406</td>
			<td>antibody for FACS</td>
		</tr>
		<tr>
			<td>Hu/NHP CD56 PE MY31</td>
			<td>BD</td>
			<td>556647</td>
			<td>antibody for FACS</td>
		</tr>
		<tr>
			<td>hu/CD19 PE-Cy7</td>
			<td>BD</td>
			<td>560728</td>
			<td>antibody for FACS</td>
		</tr>
		<tr>
			<td>human IL-2</td>
			<td>Roche</td>
			<td>11147528001</td>
			<td></td>
		</tr>
		<tr>
			<td>human serum</td>
			<td>MRC</td>
			<td>CCC118-125</td>
			<td></td>
		</tr>
		<tr>
			<td>CO2 incubator</td>
			<td>SANYO</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Techcomp</td>
			<td>CT6T</td>
			<td>Centrifugation</td>
		</tr>
		<tr>
			<td>microscope</td>
			<td>OLYMPUS CKX53</td>
			<td>CKX53</td>
			<td></td>
		</tr>
		<tr>
			<td>Automated Cell Counter</td>
			<td>Countstar</td>
			<td>IC 1000</td>
			<td>For cell counting</td>
		</tr>
		<tr>
			<td>24 well cell culture cluster</td>
			<td>Corning Incorporated</td>
			<td>3524</td>
			<td>Polystyrene plates</td>
		</tr>
		<tr>
			<td>25cm2 cell culture flask</td>
			<td>Nest</td>
			<td>707001</td>
			<td>Polystyrene</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Gibco</td>
			<td>10270</td>
			<td>Component of cell medium</td>
		</tr>
		<tr>
			<td>RPMI Medium 1640</td>
			<td>life</td>
			<td>22400089</td>
			<td>For cell medium</td>
		</tr>
		<tr>
			<td>L-Glutamine</td>
			<td>Amresco</td>
			<td>374</td>
			<td>Component of cell medium</td>
		</tr>
		<tr>
			<td>100 x streptomycin penicillin solution BioRoYeeBRY-2309</td>
			<td>BioRoYee</td>
			<td>BRY-2309</td>
			<td>Component of cell medium</td>
		</tr>
		<tr>
			<td>Ficoll paque plus</td>
			<td>GE Healthcare</td>
			<td>17-1440-03</td>
			<td>For in vitro isolation of lymphocyte</td>
		</tr>
		<tr>
			<td>DMSO</td>
			<td>Sigma</td>
			<td>D2650</td>
			<td>For freezing cells</td>
		</tr>
		<tr>
			<td>flow cytometer</td>
			<td>BD</td>
			<td>BD FACSAria II</td>
			<td></td>
		</tr>
		<tr>
			<td>soft ware</td>
			<td>BD</td>
			<td>BD FACSDiva soft ware</td>
			<td>FACS analysis</td>
		</tr>
	</tbody>
</table>

an efficient and simple method to establish nk and t cell lines from patients with chronic active epstein-barr virus infection

A number of methods have been described to establish NK/T cell lines from patients with lymphoma or lymphoproliferative syndrome. These methods employed feeder cells, purified NK or T cells with as much as 10 mL of blood, or a high-dose of IL-2. This study presents a new method with a powerful and simple strategy to establish NK and T cell lines by culturing the peripheral blood mononuclear cells (PBMC) with the addition of recombinant human IL-2 (rhIL-2), and uses as little as 2 mL of whole blood. The cells can proliferate quickly in two weeks and be maintained for more than 3 months. With this method, 7 NK or T cell lines have been established with a high success rate. This method is simple, reliable, and applicable to establishing cell lines from more cases of CAEBV or NK/T cell lymphoma.

After 3 days culture during the establishment of cell lines, the polymorphic cells begin to appear (Figure 2). After 7 days, cells grow quickly, as both the number and viability of cells are increased at a high rate (Figure 3). Small clusters of cells are clearly visible after 10-14 days growing, when the cell concentration can exceed 3-6 &#215; 106. In this period, cells should be expanded by division into two or thre...

Watch this Scientific Journal Video about An Efficient and Simple Method to Establish NK and T Cell Lines from Patients with Chronic Active Epstein-Barr Virus Infection at JoVE.com

An Efficient and Simple Method to Establish NK and T Cell Lines from Patients with Chronic Active Epstein-Barr Virus Infection

A simple method for obtaining NK and T cell clones from CAEBV patients was developed with high efficiency, a small amount of peripheral blood, and a low-dose of IL-2.

A number of methods have been described to establish NK/T cell lines from patients with lymphoma or lymphoproliferative syndrome. These methods employed ...

Research

JoVE Journal

Immunology and Infection

Derivation of Thymic Lymphoma T-cell Lines from Atm-/- and p53-/- Mice

Derivation of Thymic Lymphoma T-cell Lines from Atm-/- and p53-/- Mice

Established cell lines are a critical research tool that can reduce the use of laboratory animals in research. Certain strains of genetically modified ...

A Simple and Efficient Method to Isolate Macrophages from Mixed Primary Cultures of Adult Liver Cells

Kupffer cells are liver-specific resident macrophages and play an important role in the physiological and pathological functions of the liver1-3. Although ...

Establishment of Epstein-Barr Virus Growth-transformed Lymphoblastoid Cell Lines

Infection of B cells with Epstein-Barr virus (EBV) leads to proliferation and subsequent immortalization, resulting in establishment of lymphoblastoid ...

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 ...

A Simple and Efficient Method to Detect Nuclear Factor Activation in Human Neutrophils by Flow Cytometry

Neutrophils  are the most abundant leukocytes in peripheral blood. These cells are the first  to appear at sites of inflammation and infection, thus ...

In vivo Imaging Method to Distinguish Acute and Chronic Inflammation

In vivo Imaging Method to Distinguish Acute and Chronic Inflammation

Inflammation is a fundamental aspect of many human diseases. In this video report, we demonstrate non-invasive bioluminescence imaging techniques that ...

An Efficient and High Yield Method for Isolation of Mouse Dendritic Cell Subsets

Dendritic cells (DCs) are professional antigen-presenting cells primarily responsible for acquiring, processing and presenting antigens on antigen ...

Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of ...

Phenotypic and Functional Analysis of Activated Regulatory T Cells Isolated from Chronic Lymphocytic Choriomeningitis Virus-infected Mice

Regulatory T (Treg) cells, which express Foxp3 as a transcription factor, are subsets of CD4+ T cells. Treg cells play crucial roles in immune tolerance ...