T helper (Th) cell lineages are linked to metabolism, but precise mechanisms in human Th1 cells remain unclear. We addressed this question by in vitro stimulation and CRISPR/Cas9-mediated gene editing. Metabolic profiling revealed enhanced glycolytic activity in Th1 versus non-polarized cells, evidenced by increased extracellular acidification rate, ATP production via glycolysis, lactate secretion, NADH abundance, and elevated glycolysis-dependent anabolic activity. Inhibition of glycolysis reduced IFNγ production and STAT1 phosphorylation independent of JAK1/2 or SHP2 activity and STAT1 abundance, implicating glycolysis directly in sustaining STAT1-mediated Th1 functionality. O-glycosylation of STAT1 via O-glycosyltransferase was pivotal in modulating STAT1 activity. Pharmaceutical O-glycosyltransfer-ase inhibition prevented Th1 differentiation as well as STAT1 O-glycosylation. CRISPR/Cas9 mediated mutation of the O-glycosylation Ser499 and Thr510 sites diminished STAT1 Ser727 phosphorylation and IFNγ synthesis. Together, this study highlights glycolysis as key regulator of human Th1 cell identity and effector function, with STAT1 O-glycosylation selectively maintaining Th1 effector capacity. This mechanism could be explored to safeguard Th1 cells.
© 2025 Abir et al.

Osteosarcoma (OSA) has a dismal prognosis despite surgical resection and multiagent chemotherapy. While adoptive natural killer (NK) cell therapies have been successful in hematological malignancies, the application in solid tumors is challenging due to a tumor microenvironment (TME) that impairs NK cell tumor infiltration. Here, we found that ex vivo expansion of NK cells significantly increases the expression of C-X-C motif chemokine receptor 3 (CXCR3), one of the major proteins in the regulation of NK cell chemotaxis. Engineered over-secretion of CXCR3 ligands, C-X-C motif chemokine ligand (CXCL)9, -10, or -11, from OSA cells significantly enhanced expanded NK cell migration toward OSA cells in vitro and infiltration into the TME in vivo, with the highest NK infiltration rate in CXCL10-secreting tumors. Infusions of expanded NK cells significantly reduced (p = 0.02), and concomitant treatment with an interleukin (IL)-15 agonist NKTR-255 further reduced tumor burden and significantly increased survival in mice bearing CXCL10-secreting tumors compared with those with wild-type tumors (p = 0.02). Single-cell RNA sequencing and mass cytometry revealed upregulated apoptosis and transforming growth factor-β (TGF-β) signaling as the potential mechanisms of response/resistance to NK cell therapy in vivo. Our findings highlight potential application of chemokine-enhanced NK tumor infiltration in combination with an IL-15 agonist as a novel approach to effective treatment of OSA.
© 2025 The Authors.

Eosinophils accumulate in different tissues in allergies, cancer, and infectious diseases, adopting distinct properties. Herein, we profiled murine esophageal eosinophils during allergic inflammation using single-cell sequencing, epigenomic mapping, and flow cytometry. Esophageal eosinophils displayed an altered chromatin accessibility profile compared to bone marrow eosinophils, with 761 epi-transcriptionally regulated genes enriched in inflammation, immunoregulation, bacterial sensing, angiogenesis, migration, and apoptosis. The local environment entrains the unique esophageal eosinophil immunophenotype, as suggested by eosinophil-esophageal epithelial co-cultures, esophageal eosinophil transcriptional similarities regardless of the upstream cytokines driving their esophageal localization, and transcription factor gene editing altering esophageal eosinophilia and the associated eosinophil and global esophageal transcriptomes. Finally, the epigenomic and transcriptomic properties of murine esophageal eosinophils are largely conserved in humans. Thus, our data indicate that tissue specialization of esophageal eosinophils is entrained by local environmental cues that induce genome-wide epigenetic reprogramming and regulated by discrete transcription factors and provide a public, epigenetic database of murine tissue eosinophils.
© 2025. The Author(s).

Mitochondrial dysfunction is a hallmark of Parkinson's disease (PD), but the mechanisms by which it drives autosomal dominant and idiopathic forms of PD remain unclear. To investigate this, we generated and performed a comprehensive phenotypic analysis of a knock-in mouse model carrying the T61I mutation in the mitochondrial protein CHCHD2 (coiled-coil-helix-coiled-coil-helix domain-containing 2), which causes late-onset symptoms indistinguishable from idiopathic PD. We observed pronounced mitochondrial disruption in substantia nigra dopaminergic neurons, including distorted ultrastructure and CHCHD2 aggregation, as well as disrupted mitochondrial protein-protein interactions in brain lysates. These abnormalities were associated with a whole-body metabolic shift toward glycolysis, elevated mitochondrial reactive oxygen species (ROS), and progressive accumulation of aggregated α-synuclein. In idiopathic PD, CHCHD2 gene expression also correlated with α-synuclein levels in vulnerable dopaminergic neurons, and CHCHD2 protein accumulated in early Lewy aggregates. These findings delineate a pathogenic cascade in which CHCHD2 accumulation impairs mitochondrial respiration and increases ROS production, driving α-synuclein aggregation and neurodegeneration.

Auranofin, an FDA-approved antirheumatic drug and thioredoxin reductase 1 (TXNRD1) inhibitor, has demonstrated anti-tumoral properties, but its immunological effects are not well characterized. Here, we report that auranofin unexpectedly promotes regulatory T cell (Treg) expansion. In a B16F10 melanoma model, auranofin treatment increased lung tumor coverage, IL-10 serum levels, and FOXP3+CD44+CD4+ T cell frequencies. It also altered the proportion of antigen-presenting cells (APCs), increasing B cells and reducing dendritic cells. To test whether Treg expansion occurs independently of tumor antigens, we stimulated T cells ex vivo in lymph node cultures from naïve mice using anti-CD3/CD28, with or without auranofin. Auranofin increased Treg frequency in these cultures, as well as in treated human PBMCs. Similar effects were observed with the TXNRD1 inhibitor TRi-1, suggesting a ROS-dependent mechanism. Using mice with conditional expression of neutrophil cytosolic factor 1 (NCF1), we found that both TXNRD1 inhibition and APC-specific NCF1-NOX2-ROS expression enhanced tumor burden and Treg expansion. Alternatively, sorted T cells from mice harboring conditional TXNRD1 knockouts showed reduced FOXP3 and GITR expression in the naïve state and reduced tumor burden when challenged with B16F10. These data suggest TXNRD1 inhibitors likely drive Treg expansion by elevating ROS levels in APCs during T cell priming and less by intrinsic Treg TXNRD1 blockade. Our findings reveal a paradoxical immunosuppressive effect of TXNRD1 inhibitors that may contribute to their limited efficacy in immunocompetent cancer models. This work provides mechanistic insight and underscores the need to consider Treg-mediated immune suppression when designing TXNRD1-targeted therapies.