Alvarez, BelenRevilla, ConcepcionMoreno, SaraJimenez-Marin, AngelesRamos, ElenaMartinez de la Riva, PalomaPoderoso, TeresaGarrido, Juan JEzquerra, AngelDominguez, Javier2023-05-032023-05-032022-05-02Álvarez B, Revilla C, Moreno S, Jiménez-Marín Á, Ramos E, Martínez de la Riva P, et al. CD9 expression in porcine blood CD4+ T cells delineates two subsets with phenotypic characteristics of central and effector memory cells. Dev Comp Immunol. 2022 Aug;133:104431http://hdl.handle.net/10668/22152In this report, we describe the characterization of a new monoclonal antibody, named 4H5CR4, against porcine CD9. Its use in combination with antibodies to CD4, CD8α, and 2E3 allows to distinguish at least five main CD4+ T cell subsets. Analysis on these subsets of CD45RA, CD27, CD29, CD95, CCR7, and SLA-DR markers depicts a progressive model of CD4+ T cell development. CD4+ 2E3+ CD8α- CD9- cells are the least differentiated population of naïve cells, whereas the CD4+ 2E3- CD8α+CD9+ and CD4+ 2E3- CD8α+ CD9- cells display phenotypic features of central and effector memory T helper cells, respectively. The latter subsets were able to produce IFN-γ after polyclonal activation with PMA/Ionomycin; however, in vitro virus-specific IFN-γ production of PBMCs collected at 38-44 days after pseudorabies virus vaccination was dominated by cells with a CD9+ phenotype. Therefore, CD9 appears to be a useful marker to investigate CD4+ T cell heterogeneity in swine.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/CCR7CD4 T cellsCD9IFN-γMemorySwineAnimalsCD4-Positive T-LymphocytesCell DifferentiationImmunologic MemoryLeukocyte Common AntigensPhenotypeSwineT-Lymphocyte Subsetsresearch article35526640open accessAntígenos comunes de leucocitoDiferenciación celularFenotipoLinfocitos T CD4-positivosMemoria inmunológicaPorcinosSubgrupos de linfocitos T10.1016/j.dci.2022.1044311879-0089https://doi.org/10.1016/j.dci.2022.104431