{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T15:57:55Z","timestamp":1753891075101,"version":"3.41.2"},"reference-count":42,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,3,10]],"date-time":"2025-03-10T00:00:00Z","timestamp":1741564800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>The new targeted gene editing technologies, such as the CRISPR\/Cas system, enable researchers to insert or delete genes at targeted loci efficiently. The Cre-loxp recombination system is widely used to activate or inactivate genes with high spatial and temporal specificity.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Using the CRISPR\/Cas9 system, we inserted the <jats:italic>CreERT2<\/jats:italic> transgene expression cassette into the <jats:italic>Cd2<\/jats:italic> gene locus to generate conditional Cre-driver line <jats:italic>Cd2-CreERT2<\/jats:italic> knock-in mice, which drove the expression of CreERT2 by the endogenous <jats:italic>Cd2<\/jats:italic> promoter. By mating the <jats:italic>Cd2-CreERT2<\/jats:italic> strain with a <jats:italic>Rosa26-LSL-tdTomato<\/jats:italic> reporter mouse strain which contains a tdTomato expression fragment blocked with a loxP-flanked STOP cassette (LSL) driven by a CAG promoter, a <jats:italic>Cd2-CreERT2;Rosa26-LSL-tdTomato<\/jats:italic> reporter strain was obtained to evaluate the expression pattern of CD2 in different cell types.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>After treatment with tamoxifen, the <jats:italic>Cd2-CreERT2<\/jats:italic> knock-in mice were induced to perform efficient recombination at the <jats:italic>loxP<\/jats:italic> site following CreERT2 activation and cause the expression of tdTomato fluorescence. The tdTomato and CD2 were expressed in the T cells of peripheral blood, spleen and mesenteric lymph nodes, whereas detected in a low proportion in the B cells. While about 20% of cells labeled with tamoxifen-induced tdTomato were CD2<jats:sup>+<\/jats:sup> monocytes in peripheral blood, 10% of dendritic cells were tdTomato<jats:sup>+<\/jats:sup>\/CD2<jats:sup>+<\/jats:sup> cells. Tamoxifen-independent expression of tdTomato occurred in approximately 3% of CD2<jats:sup>+<\/jats:sup> macrophages, but in negligible (~0.5%) in CD2<jats:sup>+<\/jats:sup> granulocytes.<\/jats:p><\/jats:sec><jats:sec><jats:title>Discussion<\/jats:title><jats:p>This work supplied a new transgenic mouse as a valuable tool for lineage tracing in CD2-expressing cells, for conditional mutant studies of immune modulatory effects in a time-dependent manner, and analysis of the potential therapeutic effect of CD2-targeting biologics.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fimmu.2025.1482070","type":"journal-article","created":{"date-parts":[[2025,3,10]],"date-time":"2025-03-10T06:47:29Z","timestamp":1741589249000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Generation and characterization of a tamoxifen-inducible lineage tracing tool Cd2-P2A-CreERT2 knock-in mice"],"prefix":"10.3389","volume":"16","author":[{"given":"Yang","family":"Guo","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mengyan","family":"Zhu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhilan","family":"Yu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qing","family":"Li","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanjuan","family":"Chen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lei","family":"Ci","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ruilin","family":"Sun","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ruling","family":"Shen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,3,10]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1038\/15073","article-title":"Temporal, spatial, and cell type-specific control of Cre-mediated DNA recombination in transgenic mice","volume":"17","author":"Utomo","year":"1999","journal-title":"Nat Biotechnol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1006\/meth.1998.0593","article-title":"Inducible gene targeting in mice using the Cre\/lox system","volume":"14","author":"Sauer","year":"1998","journal-title":"Methods (San Diego Calif.)"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9440(10)61108-X","article-title":"Ligand-dependent genetic recombination in fibroblasts: a potentially powerful technique for investigating gene function in fibrosis","volume":"160","author":"Zheng","year":"2002","journal-title":"Am J Pathol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/27.22.4324","article-title":"Temporally-controlled site-specific mutagenesis in the basal layer of the epidermis: comparison of the recombinase activity of the tamoxifen-inducible Cre-ER(T) and Cre-ER(T2) recombinases","volume":"27","author":"Indra","year":"1999","journal-title":"Nucleic Acids Res"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/j.ymeth.2014.05.007","article-title":"FLP\/FRT and Cre\/lox recombination technology in C. elegans","volume":"68","author":"Hubbard","year":"2014","journal-title":"Methods (San Diego Calif.)"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1002\/dvdy.v241.5","article-title":"A novel Cre\/loxP system for mosaic gene expression in the Drosophila embryo","volume":"241","author":"Nakazawa","year":"2012","journal-title":"Dev dynamics: an Off Publ Am Assoc Anatomists"},{"key":"B7","doi-asserted-by":"publisher","first-page":"45","DOI":"10.1186\/s13036-017-0087-y","article-title":"Viral Cre-LoxP tools aid genome engineering in mammalian cells","volume":"11","author":"Sengupta","year":"2017","journal-title":"J Biol Eng"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2013.06.022","article-title":"Genome-wide generation and systematic phenotyping of knockout mice reveals new roles for many genes","volume":"154","author":"White","year":"2013","journal-title":"Cell"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1038\/nature10163","article-title":"A conditional knockout resource for the genome-wide study of mouse gene function","volume":"474","author":"Skarnes","year":"2011","journal-title":"Nature"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/j.gene.2012.11.016","article-title":"Recombinase-mediated cassette exchange (RMCE) - a rapidly-expanding toolbox for targeted genomic modifications","volume":"515","author":"Turan","year":"2013","journal-title":"Gene"},{"key":"B11","doi-asserted-by":"publisher","first-page":"4","DOI":"10.1186\/1471-213X-1-4","article-title":"Cre reporter strains produced by targeted insertion of EYFP and ECFP into the ROSA26 locus","volume":"1","author":"Srinivas","year":"2001","journal-title":"BMC Dev Biol"},{"key":"B12","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1016\/j.cellimm.2007.10.001","article-title":"Modulation of lymphocyte function with inhibitory CD2: loss of NK and NKT cells","volume":"249","author":"Ortaldo","year":"2007","journal-title":"Cell Immunol"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1002\/eji.1830190722","article-title":"Expression and ontogeny of murine CD2","volume":"19","author":"Sen","year":"1989","journal-title":"Eur J Immunol"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1038\/329842a0","article-title":"Monoclonal antibody and ligand binding sites of the T cell erythrocyte receptor (CD2)","volume":"329","author":"Peterson","year":"1987","journal-title":"Nature"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1002\/eji.1830190826","article-title":"Identical forms of the CD2 antigen expressed by mouse T and B lymphocytes","volume":"19","author":"Altevogt","year":"1989","journal-title":"Eur J Immunol"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.86.2.645","article-title":"Monoclonal antibodies specific for murine CD2 reveal its presence on B as well as T cells","volume":"86","author":"Yagita","year":"1989","journal-title":"Proc Natl Acad Sci U.S.A"},{"key":"B17","doi-asserted-by":"publisher","first-page":"399","DOI":"10.1042\/BJ20140040","article-title":"T-cell co-stimulation through the CD2 and CD28 co-receptors induces distinct signalling responses","volume":"460","author":"Sk\u00e5nland","year":"2014","journal-title":"Biochem J"},{"key":"B18","doi-asserted-by":"publisher","first-page":"192","DOI":"10.1111\/imr.2017.276.issue-1","article-title":"Advances in targeting co-inhibitory and co-stimulatory pathways in transplantation settings: the Yin to the Yang of cancer immunotherapy","volume":"276","author":"Kean","year":"2017","journal-title":"Immunol Rev"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1038\/ni1369","article-title":"The kinetic-segregation model: TCR triggering and beyond","volume":"7","author":"Davis","year":"2006","journal-title":"Nat Immunol"},{"key":"B20","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1111\/j.1600-6143.2010.03317.x","article-title":"Selective targeting of human alloresponsive CD8+ effector memory T cells based on CD2 expression","volume":"11","author":"Lo","year":"2011","journal-title":"Am J transplantation: Off J Am Soc Transplant Am Soc Transplant Surgeons"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1111\/ajt.15533","article-title":"Siplizumab selectively depletes effector memory T cells and promotes a relative expansion of alloreactive regulatory T cells in vitro","volume":"20","author":"Podest\u00e0","year":"2020","journal-title":"Am J transplantation: Off J Am Soc Transplant Am Soc Transplant Surgeons"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1835830100","article-title":"The mature activating natural killer cell immunologic synapse is formed in distinct stages","volume":"100","author":"Orange","year":"2003","journal-title":"Proc Natl Acad Sci United States America"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1172\/JCI64837","article-title":"Human immunodeficiency-causing mutation defines CD16 in spontaneous NK cell cytotoxicity","volume":"122","author":"Grier","year":"2012","journal-title":"J Clin Invest"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1262\/jrd.2020-019","article-title":"CD2 is a surface marker for mouse and rat spermatogonial stem cells","volume":"66","author":"Kanatsu-Shinohara","year":"2020","journal-title":"J Reprod Dev"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.157.5.1863","article-title":"A novel murine model for the assessment of human CD2-related reagents in vivo","volume":"157","author":"Ding","year":"1996","journal-title":"J Immunol"},{"key":"B26","doi-asserted-by":"publisher","first-page":"2209","DOI":"10.1016\/j.immuni.2021.08.029","article-title":"A Cre-driven allele-conditioning line to interrogate CD4(+) conventional T cells","volume":"54","author":"Andrews","year":"2021","journal-title":"Immunity"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0124661","article-title":"hCD2-iCre and Vav-iCre mediated gene recombination patterns in murine hematopoietic cells","volume":"10","author":"Siegemund","year":"2015","journal-title":"PLoS One"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1038\/nn.2467","article-title":"A robust and high-throughput Cre reporting and characterization system for the whole mouse brain","volume":"13","author":"Madisen","year":"2010","journal-title":"Nat Neurosci"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-59745-471-1_18","article-title":"Inducible cre mice","volume":"530","author":"Feil","year":"2009","journal-title":"Methods Mol Biol"},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.1002\/immu.200310005","article-title":"Transgenic mice with hematopoietic and lymphoid specific expression of Cre","volume":"33","author":"de Boer","year":"2003","journal-title":"Eur J Immunol"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0046590","article-title":"Activation kinetics and off-target effects of thymus-initiated cre transgenes","volume":"7","author":"Shi","year":"2012","journal-title":"PLoS One"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1002\/eji.1830191206","article-title":"Expression and function of CD2 during murine thymocyte ontogeny","volume":"19","author":"Yagita","year":"1989","journal-title":"Eur J Immunol"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.050588297","article-title":"In vivo natural killer cell activities revealed by natural killer cell-deficient mice","volume":"97","author":"Kim","year":"2000","journal-title":"Proc Natl Acad Sci U.S.A"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.1201837","article-title":"NK cell maturation and function in C57BL\/6 mice are altered by caloric restriction","volume":"190","author":"Clinthorne","year":"2013","journal-title":"J Immunol"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1038\/ni796","article-title":"In vivo developmental stages in murine natural killer cell maturation","volume":"3","author":"Kim","year":"2002","journal-title":"Nat Immunol"},{"key":"B36","doi-asserted-by":"publisher","DOI":"10.1016\/0022-1759(95)00124-S","article-title":"Improved version of a human CD2 minigene based vector for T cell-specific expression in transgenic mice","volume":"185","author":"Zhumabekov","year":"1995","journal-title":"J Immunol Methods"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1093\/intimm\/dxy064","article-title":"Identification and isolation of splenic tissue-resident macrophage sub-populations by flow cytometry","volume":"31","author":"Fujiyama","year":"2019","journal-title":"Int Immunol"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.131.2.611","article-title":"The functional significance, distribution, and structure of LFA-1, LFA-2, and LFA-3: cell surface antigens associated with CTL-target interactions","volume":"131","author":"Krensky","year":"1983","journal-title":"J Immunol (Baltimore Md.: 1950)"},{"key":"B39","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.0802008","article-title":"CD2 distinguishes two subsets of human plasmacytoid dendritic cells with distinct phenotype and functions","volume":"182","author":"Matsui","year":"2009","journal-title":"J Immunol (Baltimore Md.: 1950)"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.1242\/dev.02078","article-title":"Temporal requirement of Hoxa2 in cranial neural crest skeletal morphogenesis","volume":"132","author":"Santagati","year":"2005","journal-title":"Development"},{"key":"B41","doi-asserted-by":"publisher","DOI":"10.1007\/s00125-017-4425-x","article-title":"Gcg (CreERT2) knockin mice as a tool for genetic manipulation in pancreatic alpha cells","volume":"60","author":"Shiota","year":"2017","journal-title":"Diabetologia"},{"key":"B42","doi-asserted-by":"publisher","first-page":"5565","DOI":"10.1038\/s41467-021-25828-5","article-title":"Polymorphic estrogen receptor binding site causes Cd2-dependent sex bias in the susceptibility to autoimmune diseases","volume":"12","author":"Lahore","year":"2021","journal-title":"Nat Commun"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1482070\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,10]],"date-time":"2025-03-10T06:47:32Z","timestamp":1741589252000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1482070\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,10]]},"references-count":42,"alternative-id":["10.3389\/fimmu.2025.1482070"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2025.1482070","relation":{},"ISSN":["1664-3224"],"issn-type":[{"type":"electronic","value":"1664-3224"}],"subject":[],"published":{"date-parts":[[2025,3,10]]},"article-number":"1482070"}}