%0 Artículo %A Estrada Capetillo, Lizbeth %E Domínguez-Soto, Ángeles %E Fuentesalz-Romero, Sara %E Aragoneses-Fenoll, Laura %E Nieto, Concha %E Simón-Fuentes, Miriam %E Alonso, Bárbara %E Portolés, Pilar %E Corbí, Ángel L %E Rojo, José M %E Puig-Kröger, Amaya %D 2020 %G English %T CD28 is expressed by macrophages with anti‐inflammatory potential and limits their T‐cell activating capacity %U https://doi.org/10.1002/eji.202048806 %U https://onlinelibrary.wiley.com/doi/10.1002/eji.202048806 %X CD28 expression is generally considered to be T lymphocyte specific. We have previously shown CD28 mRNA expression in M-CSF-dependent anti-inflammatory monocyte-derived macrophages (M-MØ), and now demonstrate that CD28 cell surface expression is higher in M-MØ than in GM-CSF-dependent macrophages, and that macrophage CD28 expression is regulated by MAFB and activin A. In vivo, CD28 was found in tumor-associated macrophages and, to a lower extent, in pro-inflammatory synovial fluid macrophages from rheumatoid arthritis patients. Analysis of mouse macrophages confirmed Cd28 expression in bone-marrow derived M-MØ. Indeed, anti-CD28 antibodies triggered ERK1/2 phosphorylation in mouse M-MØ. At the functional level, Cd28KO M-MØ exhibited a significantly higher capacity to activate the OVA-specific proliferation of OT-II CD4+ T cells than WT M-MØ, as well as enhanced LPS-induced IL-6 production. Besides, the Cd28KO M-MØ transcriptome was significantly different from WT M-MØ regarding the expression IFN response, inflammatory response, and TGF-β signaling related gene sets. Therefore, defective CD28 expression in mouse macrophages associates to changes in gene expression profile, what might contribute to the altered functionality displayed by Cd28KO M-MØ. Thus, CD28 expression appears as a hallmark of anti-inflammatory macrophages and might be a target for immunotherapy.