Nonactivated CD4+CD25+ regulatory T cells constitutively express glucocorticoid-induced TNFR family-related receptor (GITR), a TNFR family member whose engagement was presumed to abrogate regulatory T cell-mediated suppression. Using GITR-/- mice, we report that GITR engagement on CD25-, not CD25+ T cells abrogates T cell-mediated suppression. Mouse APCs constitutively express GITR ligand (GITR-L), which is down-regulated following TLR signaling in vivo. Although GITR-/-CD25- T cells were capable of mounting proliferative responses, they were incapable of proliferation in the presence of physiological numbers of CD25+ T cells. Thus, GITR-L provides an important signal for CD25- T cells, rendering them resistant to CD25+ -mediated regulation at the initiation of the immune response. The down-regulation of GITR-L by inflammatory stimuli may enhance the susceptibility of effector T cells to suppressor activity during the course of an infectious insult.
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http://dx.doi.org/10.4049/jimmunol.173.8.5008 | DOI Listing |
Cancer Immunol Res
January 2025
Massachusetts Institute of Technology, Cambridge, MA, United States.
Tumor cell-intrinsic signaling pathways can drastically affect the tumor immune microenvironment, promoting tumor progression and resistance to immunotherapy by excluding immune-cell populations from the tumor. Several tumor cell-intrinsic pathways have been reported to modulate myeloid-cell and T-cell infiltration creating "cold" tumors. However, clinical evidence suggests that excluding cytotoxic T cells from the tumor core also mediates immune evasion.
View Article and Find Full Text PDFMol Med
November 2024
Department of Ophthalmic Center, The Second Affiliated Hospital of Nanchang University, No. 1 Minde Road, Nanchang, 330006, Jiangxi, China.
Background: Allergic conjunctivitis (AC) affects people's daily life and work, especially the health of children. Although there are few relevant studies, Th17/Treg imbalance plays an important role in AC development. The aim of this study was to elucidate the effect of TWEAK/Fn14 on AC and Th17/Treg balance.
View Article and Find Full Text PDFJ Immunother Cancer
October 2024
Department of Investigational Cancer Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
Sci Adv
August 2024
Armstrong Oxygen Biology Research Center and Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Adoptive cell transfer (ACT) is a therapeutic strategy to augment antitumor immunity. Here, we report that ex vivo treatment of mouse CD8 T cells with dimethyloxalylglycine (DMOG), a stabilizer of hypoxia-inducible factors (HIFs), induced HIF binding to the genes encoding the costimulatory receptors CD81, GITR, OX40, and 4-1BB, leading to increased expression. DMOG treatment increased T cell killing of melanoma cells, which was further augmented by agonist antibodies targeting each costimulatory receptor.
View Article and Find Full Text PDFCancers (Basel)
July 2024
First Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece.
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