{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T05:09:32Z","timestamp":1778735372390,"version":"3.51.4"},"reference-count":48,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T00:00:00Z","timestamp":1778544000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Open Project of GuoTai (Taizhou) Center of Technology Innovation for Veterinary Biologicals","award":["GTKF(25-002; 23-003)"],"award-info":[{"award-number":["GTKF(25-002; 23-003)"]}]},{"name":"Postgraduate Research and Practice Innovation Program of Jiangsu Province","award":["SJCX24_0242"],"award-info":[{"award-number":["SJCX24_0242"]}]},{"DOI":"10.13039\/501100012166","name":"National Key R&D Program of China","doi-asserted-by":"crossref","award":["2025YFE0209800"],"award-info":[{"award-number":["2025YFE0209800"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100012166","name":"National Key R&D Program of China","doi-asserted-by":"crossref","award":["2022YFF0710500"],"award-info":[{"award-number":["2022YFF0710500"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Veterinary Sciences"],"abstract":"<jats:p>A recently identified mesenchymal cell population, telocytes (TCs), has been found in many tissues of different animal species. Jet needle-free injection (JNFI) is a promising non-invasive drug-delivery method that can trigger effective immune responses in the skin. In this preliminary morphological study, an inactivated porcine circovirus vaccine was delivered into pig neck skin by JNFI, and untreated normal neck skin served as the control. Histopathology, immunohistochemistry (IHC), immunofluorescence (IF), and transmission electron microscopy (TEM) were used to evaluate TC distribution, ultrastructure, and selected quantitative TEM parameters 24 h after injection. TCs were widely distributed in porcine skin, located between collagen fibers and around blood vessels, adipocytes, and sweat glands. They were also observed in contact with mast cells. TCs around sweat glands were CD34+, Vimentin+, and \u03b1-SMA+, whereas TCs at other sites were CD34+, Vimentin+, and \u03b1-SMA\u2212. After JNFI, inflammatory cell infiltration into the skin was observed; TCs were in contact with these cells, and TCs surrounding adipocytes redistributed into the adjacent loose connective tissue. Quantitative TEM analysis showed that TC profile density and visible telopod length did not differ significantly between normal skin and JNFI 24 h skin (p \u2265 0.05). In contrast, vesicle profiles per TC increased significantly in both perivascular and adipose-associated compartments (p &lt; 0.05). These findings provide morphological evidence suggesting that TCs may participate in early cutaneous responses after JNFI vaccine delivery.<\/jats:p>","DOI":"10.3390\/vetsci13050467","type":"journal-article","created":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T07:44:26Z","timestamp":1778658266000},"page":"467","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Cytological Evidence of Telocyte Involvement in Skin Immune Regulation Following Jet Needle-Free Injection of an Inactivated Porcine Circovirus Vaccine"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-2516-1627","authenticated-orcid":false,"given":"Haiyan","family":"Wang","sequence":"first","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"},{"name":"GuoTai (Taizhou) Center of Technology Innovation for Veterinary Biologicals, Taizhou 225300, China"},{"name":"National Research Center of Engineering and Technology for Veterinary Biologicals, Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing210014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chunyuan","family":"Dai","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mingfa","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiasen","family":"Feng","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiangfei","family":"Meng","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhaoxuan","family":"Zhu","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-9780-4570","authenticated-orcid":false,"given":"Xinzi","family":"Guo","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ping","family":"Yang","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yu","family":"Lu","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, China"},{"name":"GuoTai (Taizhou) Center of Technology Innovation for Veterinary Biologicals, Taizhou 225300, China"},{"name":"National Research Center of Engineering and Technology for Veterinary Biologicals, Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing210014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Mestrallet, G., Rouas-Freiss, N., LeMaoult, J., Fortunel, N.O., and Martin, M.T. (2021). Skin immunity and tolerance: Focus on epidermal keratinocytes expressing hla-g. Front. Immunol., 12.","DOI":"10.3389\/fimmu.2021.772516"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1038\/nri1310","article-title":"Immune surveillance in the skin: Mechanisms and clinical consequences","volume":"4","author":"Kupper","year":"2004","journal-title":"Nat. Rev. Immunol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1038\/s41577-018-0084-5","article-title":"The immunological anatomy of the skin","volume":"19","author":"Kabashima","year":"2019","journal-title":"Nat. Rev. Immunol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1016\/j.celrep.2016.12.078","article-title":"T cell migration from inflamed skin to draining lymph nodes requires intralymphatic crawling supported by icam-1\/lfa-1 interactions","volume":"18","author":"Teijeira","year":"2017","journal-title":"Cell Rep."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e00034-18","DOI":"10.1128\/CMR.00034-18","article-title":"Organization of the skin immune system and compartmentalized immune responses in infectious diseases","volume":"32","author":"Quaresma","year":"2019","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1016\/j.immuni.2011.12.003","article-title":"The multitasking organ: Recent insights into skin immune function","volume":"35","author":"Perera","year":"2011","journal-title":"Immunity"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1038\/jid.2012.284","article-title":"Update of immune events in the murine contact hypersensitivity model: Toward the understanding of allergic contact dermatitis","volume":"133","author":"Honda","year":"2013","journal-title":"J. Investig. Dermatol."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Shi, Z., Liu, Z., Wei, Y., Zhang, R., Deng, Y., and Li, D. (2024). The role of dermal fibroblasts in autoimmune skin diseases. Front. Immunol., 15.","DOI":"10.3389\/fimmu.2024.1379490"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Cioce, A., Cavani, A., Cattani, C., and Scopelliti, F. (2024). Role of the skin immune system in wound healing. Cells, 13.","DOI":"10.3390\/cells13070624"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"729","DOI":"10.1111\/j.1582-4934.2010.01059.x","article-title":"TELOCYTES\u2014A case of serendipity: The winding way from interstitial cells of cajal (ICC), via interstitial cajal-like cells (ICLC) to TELOCYTES","volume":"14","author":"Popescu","year":"2010","journal-title":"J. Cell. Mol. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1186\/s12576-023-00868-2","article-title":"Telocytes response to cardiac growth induced by resistance exercise training and endurance exercise training in adult male rats","volume":"73","author":"Choobineh","year":"2023","journal-title":"J. Physiol. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1680","DOI":"10.1002\/cbin.12223","article-title":"Cd34(+) stromal cells\/telocytes and their role in mouse lung development: Light microscopy, immunofluorescence, ultrastructural and scanning electron microscopy evidence","volume":"48","author":"Dama","year":"2024","journal-title":"Cell Biol. Int."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1733","DOI":"10.1002\/jemt.24549","article-title":"The telocytes relationship with satellite cells: Extracellular vesicles mediate the myotendinous junction remodeling","volume":"87","author":"Batista","year":"2024","journal-title":"Microsc. Res. Tech."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1007\/s00441-010-1095-0","article-title":"Telocytes in pleura: Two- and three-dimensional imaging by transmission electron microscopy","volume":"343","author":"Hinescu","year":"2011","journal-title":"Cell Tissue Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1111\/j.1582-4934.2010.01207.x","article-title":"Identification of telocytes in the lamina propria of rat duodenum: Transmission electron microscopy","volume":"15","author":"Escribano","year":"2011","journal-title":"J. Cell. Mol. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1016\/j.aanat.2011.11.007","article-title":"Skin telocytes","volume":"194","author":"Rusu","year":"2012","journal-title":"Ann. Anat."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2131955","DOI":"10.1080\/21688370.2022.2131955","article-title":"A cellular regulator of the niche: Telocyte","volume":"11","author":"Babadag","year":"2023","journal-title":"Tissue Barriers"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1007\/s00418-023-02186-5","article-title":"Identification and protective role of cd34(+) stromal cells\/telocytes in experimental autoimmune encephalomyelitis (EAE) mouse spleen","volume":"160","author":"Dama","year":"2023","journal-title":"Histochem. Cell Biol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Valente, S., Lahoz, M.V., Vasuri, F., and Pasquinelli, G. (2024). Immunohistochemical and ultrastructural characterization of telocytes in normal and diabetic human kidneys. Biomolecules, 14.","DOI":"10.3390\/biom14080968"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Sanches, B.D.A., Rocha, L.C., Neto, J.P., Beguelini, M.R., Ciena, A.P., and Carvalho, H.F. (2024). Telocytes of the male reproductive system: Dynamic tissue organizers. Front. Cell Dev. Biol., 12.","DOI":"10.3389\/fcell.2024.1444156"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.semcdb.2016.01.036","article-title":"Telocyte\u2019s contacts","volume":"55","author":"Gherghiceanu","year":"2016","journal-title":"Semin. Cell Dev. Biol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"714","DOI":"10.1111\/j.1582-4934.2005.tb00502.x","article-title":"The connective connection: Interstitial cells of cajal (ICC) and ICC-like cells establish synapses with immunoreactive cells. Electron microscope study in situ","volume":"9","author":"Popescu","year":"2005","journal-title":"J. Cell. Mol. Med."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"E35983","DOI":"10.1097\/MD.0000000000035983","article-title":"Telocytes and inflammation: A review","volume":"102","author":"Zhang","year":"2023","journal-title":"Medicine"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Wang, X., Zhang, P., Tang, Y., Chen, Y., Zhou, E., and Gao, K. (2024). Mast cells: A double-edged sword in inflammation and fibrosis. Front. Cell Dev. Biol., 12.","DOI":"10.3389\/fcell.2024.1466491"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Manole, C.G., Voiculescu, V.M., Soare, C., Ceafalan, L.C., Gherghiceanu, M., and Hinescu, M.E. (2024). Skin telocytes could fundament the cellular mechanisms of wound healing in platelet-rich plasma administration. Cells, 13.","DOI":"10.3390\/cells13161321"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"13899","DOI":"10.1038\/s41598-024-63802-5","article-title":"Immunohistochemical-properties of the dermal embryonic telocytes","volume":"14","author":"Soliman","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1007\/978-3-030-73119-9_11","article-title":"Telocytes in the tumor microenvironment","volume":"Volume 1329","author":"Aleksandrovych","year":"2021","journal-title":"Tumor Microenvironment; Advances in Experimental Medicine and Biology"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"9636897221105252","DOI":"10.1177\/09636897221105252","article-title":"Telocytes in fibrosis diseases: From current findings to future clinical perspectives","volume":"31","author":"Wei","year":"2022","journal-title":"Cell Transplant."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1186\/s12967-020-02217-y","article-title":"Telocytes inhibited inflammatory factor expression and enhanced cell migration in lps-induced skin wound healing models in vitro and in vivo","volume":"18","author":"Wang","year":"2020","journal-title":"J. Transl. Med."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1038\/nrd2076","article-title":"Current status and future prospects of needle-free liquid jet injectors","volume":"5","author":"Mitragotri","year":"2006","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"114109","DOI":"10.1016\/j.addr.2021.114109","article-title":"Jet injectors: Perspectives for small volume delivery with lasers","volume":"182","author":"Schoppink","year":"2022","journal-title":"Adv. Drug Deliv. Rev."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"231","DOI":"10.2147\/CCID.S162724","article-title":"Current trends in needle-free jet injection: An update","volume":"11","author":"Barolet","year":"2018","journal-title":"Clin. Cosmet. Investig. Dermatol."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Wang, C., Tang, X., Jiang, C., Zhang, Y., Han, B., Sun, Y., Guo, J., Peng, H., Wang, Z., and Wang, Y. (2025). Intradermal delivery of SARS-CoV-2 RBD3-fc mRNA vaccines via a needle-free injection system induces robust immune responses in rats. Front. Immunol., 16.","DOI":"10.3389\/fimmu.2025.1530736"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.tim.2011.11.002","article-title":"The pig: A model for human infectious diseases","volume":"20","author":"Meurens","year":"2012","journal-title":"Trends Microbiol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.molimm.2014.10.023","article-title":"The immunology of the porcine skin and its value as a model for human skin","volume":"66","author":"Summerfield","year":"2015","journal-title":"Mol. Immunol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Dalmau, A., S\u00e1nchez-Matamoros, A., Molina, J.M., Xercavins, A., Varvar\u00f3-Porter, A., Mu\u00f1oz, I., Moles, X., Baulida, B., F\u00e0brega, E., and Velarde, A. (2021). Intramuscular vs. Intradermic needle-free vaccination in piglets: Relevance for animal welfare based on an aversion learning test and vocalizations. Front. Vet. Sci., 8.","DOI":"10.3389\/fvets.2021.715260"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1002\/lsm.23191","article-title":"Needle-free injection assisted drug delivery-histological characterization of cutaneous deposition","volume":"52","author":"Erlendsson","year":"2020","journal-title":"Lasers Surg. Med."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Temple, D., Jim\u00e9nez, M., Escribano, D., Mart\u00edn-Valls, G., D\u00edaz, I., and Manteca, X. (2020). Welfare benefits of intradermal vaccination of piglets. Animals, 10.","DOI":"10.3390\/ani10101898"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1405","DOI":"10.1111\/j.1582-4934.2012.01580.x","article-title":"Telocytes in human skin\u2014Are they involved in skin regeneration?","volume":"16","author":"Ceafalan","year":"2012","journal-title":"J. Cell. Mol. Med."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"D\u00edaz-Flores, L., Guti\u00e9rrez, R., Garc\u00eda, M.P., Gonz\u00e1lez-G\u00f3mez, M., Rodr\u00edguez-Rodriguez, R., Hern\u00e1ndez-Le\u00f3n, N., D\u00edaz-Flores, L., and Carrasco, J.L. (2021). Cd34+ stromal cells\/telocytes in normal and pathological skin. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22147342"},{"key":"ref_41","first-page":"853","article-title":"Immunophenotypic characterization of telocyte-like cells in pterygium","volume":"24","author":"Maxia","year":"2018","journal-title":"Mol. Vis."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Gandahi, N.S., Ding, B., Shi, Y., Bai, X., Gandahi, J.A., Vistro, W.A., Chen, Q., and Yang, P. (2020). Identification of telocytes in the pancreas of turtles-a role in cellular communication. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21062057"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1007\/978-981-10-1061-3_12","article-title":"Telocyte behaviour during inflammation, repair and tumour stroma formation","volume":"Volume 913","author":"Valladares","year":"2016","journal-title":"Telocytes; Advances in Experimental Medicine and Biology"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1007\/978-981-10-1061-3_4","article-title":"Telocytes in chronic inflammatory and fibrotic diseases","volume":"Volume 913","author":"Rosa","year":"2016","journal-title":"Telocytes; Advances in Experimental Medicine and Biology"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"D\u00edaz-Flores, L., Guti\u00e9rrez, R., Garc\u00eda, M.P., Gayoso, S., Guti\u00e9rrez, E., D\u00edaz-Flores, L., and Carrasco, J.L. (2020). Telocytes in the normal and pathological peripheral nervous system. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21124320"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"2069","DOI":"10.1017\/S1431927622012302","article-title":"Evaluation of the plasticity of novel regulatory cells-telocytes-in the gonad of the male chinese soft-shelled turtle (Pelodiscus sinensis) associated with seasonal reproductive activity","volume":"28","author":"Meng","year":"2022","journal-title":"Microsc. Microanal."},{"key":"ref_47","first-page":"237","article-title":"Cardiac telocyte-derived exosomes and their possible implications in cardiovascular pathophysiology","volume":"Volume 998","author":"Marini","year":"2017","journal-title":"Exosomes in Cardiovascular Diseases; Advances in Experimental Medicine and Biology"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"3935","DOI":"10.1002\/ehf2.13460","article-title":"Telocytes-derived extracellular vesicles alleviate aortic valve calcification by carrying miR-30b","volume":"8","author":"Yang","year":"2021","journal-title":"ESC. Heart Fail."}],"container-title":["Veterinary Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2306-7381\/13\/5\/467\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T04:18:13Z","timestamp":1778732293000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2306-7381\/13\/5\/467"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,12]]},"references-count":48,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["vetsci13050467"],"URL":"https:\/\/doi.org\/10.3390\/vetsci13050467","relation":{},"ISSN":["2306-7381"],"issn-type":[{"value":"2306-7381","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,12]]}}}