Project description:The adenosine 2A receptor (A2AR) is expressed on regulatory T cells (Tregs), but the functional significance is currently unknown. We compared the gene expression between wild-type (WT) and A2AR knockout (KO) Tregs and between WT Tregs treated with vehicle or a selective A2AR agonist. FACS-sorted GFP positive Tregs from WT or A2AR KO FoxP3GFP mouse spleen and lymph nodes were incubated 18 hr with vehicle (DMSO), a separate set of WT Tregs were incubated with the selective A2AR agonist ATL1222 10 nM (Dogwood Pharmaceuticals, Inc.) for 18 hr prior to RNA isolation.
Project description:The adenosine 2A receptor (A2AR) is expressed on regulatory T cells (Tregs), but the functional significance is currently unknown. We compared the gene expression between wild-type (WT) and A2AR knockout (KO) Tregs and between WT Tregs treated with vehicle or a selective A2AR agonist.
Project description:Analysis of venticular myocardium from adenosine 2A receptors (A2AR) knockouts following LPS stimulation. Results provide insight into the molecular components of A2AR mediated protection, but also reveal pathogenetic components of endotoxemic myocarditis as a result of LPS exposure. These findings demonstrate that intrinsic A2AR activity exerts limited transcriptional effects in unstressed heart, modifying G-coupled cAMP/PKA signal paths. LPS-dependent injury and dysfunction is associated with profound up-regulation of inflammatory/immune processes, fibrotic and cell death paths, and NF-kB, Erk/MAPK and JAK/Stat signaling, with shifts in multiple determinants of cardiac contraction and survival. Intrinsic A2AR activity modulates key aspects of these inflammatory responses, involving MAPK, JAK/Stat and NF-kB signaling Total RNA obtained from adenosine 2A receptor knockout or wild-type murine ventricular myocardium that were treated for 24 hours with either saline or lipopolysaccharide (n=4/group).
Project description:Analysis of venticular myocardium from adenosine 2A receptors (A2AR) knockouts following LPS stimulation. Results provide insight into the molecular components of A2AR mediated protection, but also reveal pathogenetic components of endotoxemic myocarditis as a result of LPS exposure. These findings demonstrate that intrinsic A2AR activity exerts limited transcriptional effects in unstressed heart, modifying G-coupled cAMP/PKA signal paths. LPS-dependent injury and dysfunction is associated with profound up-regulation of inflammatory/immune processes, fibrotic and cell death paths, and NF-kB, Erk/MAPK and JAK/Stat signaling, with shifts in multiple determinants of cardiac contraction and survival. Intrinsic A2AR activity modulates key aspects of these inflammatory responses, involving MAPK, JAK/Stat and NF-kB signaling
Project description:Adenosine is an ubiquitous neuromodulator that ensures cerebral homeostasis. It exerts numerous functions through the activation of G-protein-coupled adenosine receptors (ARs), in particular A1 (A1R) and A2A (A2AR) receptors. Interestingly, A2AR levels are upregulated in cortical and hippocampal regions in several pathological conditions such as Alzheimer's disease, tauopathies or epilepsia. Such abnormal upregulations have been particularly reported in astrocytes, glial cells that play a key role in regulating synaptic plasticity. However, the overall impact and the underlying mechanisms associated with increased A2AR in astrocytes remain poorly understood. In the present study, we induced the upregulation of A2AR in hippocampal astrocytes using dedicated AAVs and comprehensively evaluated the functional consequences in 4 months-old C57Bl6/J mice. Our results show that A2AR upregulation primarily promotes alterations of astrocyte reactivity, morphology and transcriptome, with a link to aging-like phenotype as well as secondary impairments of neuronal excitability and microglial phenotype. These changes driven by a restricted A2AR upregulation in hippocampal astrocytes were sufficient to induce impairments of short-term spatial memory and spatial learning. This study highlights the impact of astrocytic A2AR upregulation, as seen in various neurological conditions, on the development of a detrimental multicellular response associated with memory alterations and provides an additional proof-of-concept for the value of targeting this receptor in different neurodegenerative conditions.
Project description:To understand the mechanisms through which JunB regulates Tregs-mediated immune regulation, we examined the global gene expression profiles in the JunB WT and KO Tregs by performing RNA sequencing (RNA-seq) analysis.
Project description:High levels of extracellular adenosine, highly abundant in the tumor microenvironment, promote immune suppression mainly through the A2AR expressed by tumor-infiltrating immune cells. Here we show that plasma cells are the most negatively affected by adenosine among the immune cells present in the tumor microenvironment.
Project description:Although A2AR is a key immunoregulatory receptor that suppresses CD8⁺ T-cell activation in response to elevated extracellular adenosine in inflamed or hypoxic microenvironments, its role in CD8⁺ T cell differentiation and cell-fate decisions during chronic viral infection and cancer remains poorly understood. Using A2AR-eGFP reporter mice, we show that A2AR expression is rapidly induced by TCR stimulation and persists under chronic antigen exposure and hypoxia, with sustained expression strongly associated with terminal exhaustion via the canonical Gαs–cAMP–PKA pathway. Paradoxically, A2AR loss does not alleviate exhaustion but instead accelerates differentiation toward the terminally exhausted state. Single-cell multiomics profiling revealed that A2AR deficiency activates CD122 (IL-2Rβ)–dependent signaling, driving T-cell exhaustion. Genetic deletion of CD122 in A2AR-deficient CD8⁺ T cells reduced terminal exhaustion, identifying CD122 signaling as a key mediator of A2AR loss–driven exhaustion. Intriguingly, both sustained A2AR expression and A2AR loss converge to promote T cell exhaustion differentiation through distinct mechanisms. These findings uncover a paradoxical role of A2AR in shaping CD8⁺ T cell fate choices during chronic infection and cancer.