Pulmonary fibrosis has a poor prognosis because of challenges in early diagnosis and therapeutic intervention. Current treatments remain largely ineffective due to an incomplete understanding of the complex pathology, including the interactions between fibroblasts and profibrotic immune cells within fibrotic lungs. To elucidate the dynamics of fibrosis, we performed single-cell RNA sequencing on bronchoalveolar lavage fluid obtained from patients with interstitial lung disease (ILD). We identified the SPP1- and APOE-expressing macrophage population that is commonly present across ILDs. Histological analysis showed that this macrophage population accumulated at the center of fibrotic foci. Furthermore, the ratio of this macrophage population was increased in both progressive pulmonary fibrosis and idiopathic pulmonary fibrosis. Transcriptomic analysis further divided this macrophage population into two subsets: SLC40A1⁺ or HAMP⁺ fibrosis-associated macrophages. We found that the relative balance of IL-10 and IL-8 regulated SLC40A1 and HAMP expression within fibrosis-associated macrophages. Additionally, histological analysis revealed that bronchial epithelium expressed IL-8, while type II alveolar epithelial cells expressed IL-10 in the fibrotic lung. SLC40A1⁺ fibrosis-associated macrophages localized to CD31⁺ perivascular regions and mediated the uptake and degradation of the hemoglobin-haptoglobin complex. This dual pathway-providing iron via SLC40A1 and intracellular iron accumulation via HAMP-facilitated the transition of fibroblasts into SPP1⁺ myofibroblasts. Moreover, ferroptotic fibroblasts secreted transforming growth factor-beta 1 (TGF-β1), which further contributes to fibrotic progression. In conclusion, aberrant iron metabolism orchestrated by fibrosis-associated macrophages may contribute to fibrosis by facilitating the transition of myofibroblasts. These findings provide mechanistic insight into the progression of autonomous pulmonary fibrosis.

Craniosynostosis is a major craniofacial congenital disorder that causes developmental complications. During normal cranial development, intramembranous ossification forms the flat bones and sutures, while cartilage appears transiently in the posterior calvarial region. However, in craniosynostosis, premature suture fusion disturbs normal calvarial morphogenesis. To clarify the role of transient cartilage in this morphogenetic disruption, we investigated its molecular regulation and pathology in mice, focusing on parathyroid hormone 1 receptor (Pth1r) signaling. Conditional deletion of Pth1r in the cranial mesenchyme unexpectedly caused acrocephalic dysmorphology and craniosynostosis, with altered cartilage differentiation. Occipito-interparietal synostosis consistently occurred in Pth1r-ablated Gli1+ and Acan+ lineages, but not after adult Gli1-Cre ERT2 deletion, indicating a developmental role. Bulk and single-cell RNA-seq analysis revealed nine mesenchymal subsets, with mutant cells showing abnormal chondrocyte differentiation and upregulated Indian hedgehog (Ihh) signaling. These findings indicate that Pth1r maintains proper chondrogenic regulation during calvarial development, and its loss induces craniosynostosis through Ihh overactivation.

BACKGROUND Appendectomy reduces the occurrence and controls the severity of ulcerative colitis (UC); however, how it exerts these effects remains unclear. AIM To elucidate the contribution of appendix-associated immune responses in intestinal inflammation and their relevance to the effects of appendectomy in UC. METHODS This study was conducted at Graduate School of Medicine, The University of Osaka. We included patients undergoing surgery for UC and those without inflammatory bowel disease undergoing colorectal cancer surgery as controls. Appendiceal tissues were collected from both patient groups, and macroscopically normal appendices located at least 10 cm from the tumor were used as controls. Single-cell RNA sequencing, immunohistochemistry, and flow cytometry were performed. RESULTS Single-cell RNA sequencing identified T, B, plasma, innate lymphoid, and mast cells, together with other myeloid cells in appendiceal tissues. A hallmark feature of the appendices in UC was an increase in immunoglobulin G (IgG)-expressing plasma cells. Immunohistochemistry revealed significantly reduced IgG levels in the large intestines of patients with UC who had undergone an appendectomy compared with levels in those who did not undergo appendectomy. Repertoire analysis revealed an increased production of IgG antibodies bearing an integrin-binding motif at antigen-recognition sites in patients with UC. CONCLUSION The appendix is a major site of pathogenic IgG antibody production in patients with UC, providing the immunological basis for appendectomy as a treatment for UC.

Toxoplasma gondii, which can virtually infect all warm-blooded cells, secretes various virulence factors to evade interferon-gamma (IFN-γ)-dependent host immunity. While these secreted proteins are widely characterized, the molecular mechanisms important for virulence within the parasite are unclear. In this study, we aimed to investigate the roles of non-secretory proteins of T. gondii in immunosuppression. Deletion of deubiquitinase TgJosephin resulted in attenuated virulence in wild-type mice but not in mice lacking the interferon-gamma receptor (IFNγR). Moreover, TgJosephin expression was maintained by TgRad23, a protein involved in DNA repair and protein shuttling. Notably, TgJosephin depletion increased ubiquitination of subpellicular microtubule protein 1 (SPM1), a stabilizing component of the parasite microtubules, and mutating its ubiquitination sites restored virulence in the absence of TgJosephin. We propose TgJosephin as a novel virulence factor maintained by TgRad23 and a virulence pathway involving SPM1 metabolism.IMPORTANCEToxoplasma gondii is an obligate parasite whose infection can be detrimental when combined with pregnancy or immunodeficiency. Studies on T. gondii virulence have revealed various secretory proteins that inhibit the host interferon-gamma (IFN-γ) immune response. However, much of the broader virulence landscape remains unclear. To explore the unknown molecular pathways of T. gondii virulence in mice, we searched for immunosuppressive functions in genes encoding non-secretory proteins, associated with fundamental cellular processes of the virulent type I strain. Here, we found that TgJosephin, a highly conserved deubiquitinase, was important for virulence in wild-type mice but not mice lacking the IFN-γ receptor (IFNγR). In addition, TgJosephin expression was dependent on TgRad23, and loss of TgJosephin led to increased ubiquitination of a microtubule protein SPM1. Our results suggest a novel anti-IFN-γ pathway of T. gondii mediated by TgJosephin and SPM1 deubiquitination.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibody production. Extrafollicular (EF) B cell responses contribute to SLE pathogenesis, with age-associated B cells (ABCs) giving rise to autoantibody-secreting plasmablasts (PBs). However, the migratory cues governing this EF trajectory remain unclear. Here, we identify a distinct ABC state with PB precursor characteristics (pre-PB ABCs) and reveal a migration-dependent program underlying their generation. Single-cell analysis of patients with SLE and model mice showed that pre-PB ABCs were enriched in autoreactive clones and poised for PB differentiation. Their frequency correlated with autoantibody titers and disease activity, underscoring their pathogenic relevance. We further demonstrated that the oxysterol receptor EBI2 directed ABCs to EF niches within splenic bridging channels, promoting pre-PB ABC formation and autoreactive PB output. This process depended on the COMMD3/8 complex, a positive regulator of chemoattractant receptor signaling. Beyond EBI2-mediated ABC migration to EF niches, the COMMD3/8 complex was also required for trafficking of autoantibody-secreting cells to the bone marrow and infiltration of ABCs into the kidney. Accordingly, COMMD3/8 complex inhibition ameliorated disease in murine SLE models. These findings define a migration-dependent mechanism driving the EF differentiation of ABCs into autoreactive PBs and shaping the tissue distribution of pathogenic B cells, highlighting this program as a potential therapeutic target in SLE.

Members of the Batf family, including Batf, Batf2, and Batf3, play critical roles in various immune cell types. Several studies have suggested redundant functions, as they can compensate for each other's functions. Here, we show that transduction of Batf family members confers distinct functional characteristics on CD8+ T cells. Batf- and Batf2-transduced CD8+ T cells exhibited effector and memory-like phenotypes, respectively. Notably, Batf3-transduced CD8+ T cells showed both effector- and memory-like phenotypes in response to effector- and memory-associated cytokines, respectively, and superior anti-tumor activity in vivo among Batf family members. Our results demonstrated that each Batf family member has distinct functions in CD8+ T cells. These findings help us understand the roles of the Batf family members in CD8+ T cells and contribute to the development of optimized adoptive T cell therapies against cancer.

Cancer cells confronting oxidative stress must coordinate their extracellular vesicle (EV) secretion to balance intercellular signaling with the intracellular programs required for survival, yet how these decisions are integrated remains poorly understood. Here, we identify a stress-adaptive mechanism in which stress granules (SGs) selectively suppress CD63+ EV release. Using a bioluminescent EV-reporter screen, we found that the clinical compound YM155 selectively inhibits CD63+ EV secretion across diverse tumor cells. Mechanistically, YM155 rapidly inactivates the antioxidant transcription factor FOXO3a, diminishing expression of key detoxifying enzymes and leading to delayed but sustained accumulation of reactive oxygen species (ROS). Elevated ROS drives SG formation, and these SGs function not as passive storage sites but as RNA triage hubs that exclude and destabilize a subset of transcripts. Among them, Rab27A mRNA-encoding a GTPase essential for multivesicular-body docking to the plasma membrane-is selectively excluded and degraded, resulting in loss of Rab27A protein and suppression of CD63+ EV secretion. Forced Rab27A expression restores EV release but paradoxically reduces proliferation under oxidative stress, indicating that EV suppression is prosurvival. The same FOXO3a-ROS-SG-Rab27A axis operates during physiological glucose deprivation and is evident in vivo, where SGs form in xenograft tumors and circulating CD63+ EVs decline. Pancancer transcriptomic analyses further show that Rab27A expression correlates with FOXO3a-dependent antioxidant programs, underscoring clinical relevance. These findings reveal that SGs actively reprogram RNA fate to tune vesicle output, establishing a redox-responsive mechanism by which cancer cells transiently suppress EV secretion to enhance survival.

Adoptive T cell therapy can induce tumor regression in cancer patients. Tumor-specific CD8+ T cells regenerated from induced pluripotent stem cells (iPSCs), termed regenerated cytotoxic T lymphocytes (CTLs), are promising resources for adoptive T cell therapy. However, little is known about the cytokines that enhance anti-tumor activity of regenerated CTLs. In this study, we examined effects of exogenous cytokines on regenerated CTLs. We found that IL-15 and IL-21 treatment enhanced the anti-tumor activity of regenerated CTLs, and these cells showed distinct gene expression profiles. IL-15-treated regenerated CTLs exhibited early-effector-like characteristics, whereas IL-21-treated regenerated CTLs exhibited both naive-and effector-like characteristics. Furthermore, we investigated effects of cytokine transduction on regenerated CTLs. IL-2, IL-7, or IL-15 transduction, but not IL-21 transduction, enhanced the survival and cytotoxic activity of regenerated CTLs. Importantly, IL-7 transduction improved the anti-tumor activity of regenerated CTLs in vivo. These findings provide insights for the clinical application of regenerated CTLs.

Nakajo-Nishimura syndrome/proteasome-associated autoinflammatory syndrome (NNS/PRAAS) is a hereditary autoinflammatory disease. Clinically, NNS/PRAAS is characterized by periodic fever, skin rash, partial lipo-muscular atrophy, and joint contractures. Among PRAAS, NNS, is genetically characterized by a homozygous founder variant in the proteasome subunit beta type 8 (PSMB8) gene encoding an inducible proteasome component β5i. To establish an in vivo animal model recapitulating NNS/PRAAS, we generated mice harboring this founder variant. In Psmb8G201V/G201V mice, the immature β5i subunit was increased and 20S proteasome activity was significantly reduced in the spleen, whereas 26S proteasome activity was preserved and ubiquitin accumulation was not apparent. Compared with wild-type mice, Psmb8G201V/G201V mice exhibited a shortened lifespan and, as they aged, showed less weight gain and adipocyte shrinkage with interstitial macrophage infiltration and cytokine production/activation. The mutant mice also manifested significantly lower proportion of T cells in total splenocytes, with higher CD4+ and lower CD8+ T cell proportions. Psmb8G201V/G201V mice shared some characteristic autoinflammatory and progeroid phenotypes as observed in NNS/PRAAS patients, although their proteasome defect pattern was distinct. Thus, Psmb8G201V/G201V mice should be useful not only for investigation of NNS/PRAAS pathogenesis but also for examining the clinical effect of candidate drugs on NNS/PRAAS and related diseases.

BACKGROUND & AIMS:Inflammatory bowel disease involves intractable intestinal inflammation often refractory to current pharmacotherapies. We investigated the therapeutic potential of a novel, orally available inhibitor targeting α-1,6-fucosyltransferase-the sole glycosyltransferase catalyzing core fucosylation of N-glycans in mammals-as an anti-inflammatory agent. METHODS:α-1,6-Fucosyltransferase inhibitor efficacy was evaluated in 2 murine models: a trinitrobenzene sulfonic acid-induced colitis model and a naive CD4+ T-cell adoptive transfer model using recombination activating gene 2 (Rag2)-deficient mice. Amelioration of trinitrobenzene sulfonic acid-induced colitis by the α-1,6-fucosyltransferase inhibitor was also evaluated in LckcreFut8fl/fl mice in which α-1,6-fucosyltransferase is conditionally abrogated in T cells. Splenic CD4+ T cells from wild-type mice were treated with the α-1,6-fucosyltransferase inhibitor to evaluate its effects on cell signaling, cytokine production, and T helper 1, 2, and 17 differentiation. In vivo safety was assessed in wild-type mice. RESULTS:Oral administration of the α-1,6-fucosyltransferase inhibitor effectively decreased T-cell core fucosylation and ameliorated trinitrobenzene sulfonic acid-induced colitis and colitis induced by adoptive T-cell transfer. These clinical effects were accompanied by decreased T helper 1 and 2 cytokine production from CD4+ T cells. Trinitrobenzene sulfonic acid-induced colitis was attenuated in LckcreFut8fl/fl mice, demonstrating that the ameliorative effect of α-1,6-fucosyltransferase inhibition is directly mediated by T cells. In vitro, the inhibitor suppressed T-cell signal transduction and T helper 1, 2, and 17 cell differentiation. No apparent hepatorenal toxicity or intestinal mucus layer disruption was observed. CONCLUSIONS:α-1,6-Fucosyltransferase inhibition modulated T-cell core fucosylation and reduced inflammation in murine colitis models without apparent toxicity, indicating that targeting α-1,6-fucosyltransferase may offer a novel therapeutic approach for inflammatory bowel disease by disrupting proinflammatory T-cell responses.

In pancreatic cancer, cancer stem-like cells (CSCs) contribute to tumor initiation, reduced drug sensitivity, and recurrence. Limited strategies are currently available to target this cell population. Here we used a proteasome-low CSC enrichment system to identify microRNAs that negatively regulate CSC-like properties. From PANC-1 cells expressing a ZsGreen-ODC degron reporter, a proteasome-low population was isolated through sequential fluorescence-activated cell sorting of ZsGreen-positive cells. Molecular and functional analyses confirmed the CSC-like phenotype of this cell population. Integrated in silico analysis was used to select 31 microRNAs predicted to target CSC-related molecules, which were then evaluated by in vitro viability-based screening to identify candidates that selectively suppressed the viability of CSC-like cells, relative to non-CSCs. Moreover, comprehensive miRNA expression profiling revealed that miR-136-5p was downregulated in the CSC-like population and was therefore selected for further analysis. Mechanistically, miR-136-5p directly targets the 3 ' untranslated region of DCLK1 and reduces its expression, with a greater reduction in the short isoform. Finally, in a CSC-derived xenograft mouse model, systemic delivery of miR-136-5p using super carbonate apatite nanoparticles significantly suppressed tumor growth. Taken together, these findings suggest that miR-136-5p restoration may provide a therapeutic approach for targeting CSC-driven tumor growth in pancreatic cancer.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that causes motor neuron degeneration. However, the mechanisms underlying the selective vulnerability of motor neurons and the involvement of non-motor neuron cells in ALS remain unclear. To investigate ALS pathology at the cellular level, we performed a single-nucleus multiome analysis, including RNA sequencing and chromatin accessibility profiling, on motor cortex (75,583 nuclei) and spinal cord (62,711 nuclei) from patients with ALS (n=6) and controls (n=6). Our results revealed significant gene expression changes specifically in spinal motor neurons, including upregulation of a metabotropic glutamate receptor, GRM5, and enhanced glutamate signaling. By integrating genome-wide association study data, we identified ALS-associated SNPs in regulatory regions, suggesting cell-type-specific enrichment of risk, especially in microglia. These findings suggest that changes in spinal motor neurons and their surrounding environment, including glutamate signaling, may be involved in ALS pathology. The study also provides valuable resources for future research on the underlying mechanisms and potential therapeutic targets.

Salivary gland function declines with age, contributing to periodontitis and aspiration pneumonia. However, the cellular mechanisms that preserve secretion during aging remain unclear. Mice were stratified by aging stage, and saliva output and tissue histology were assessed. To infer cell–cell communication, regions surrounding lymphocyte clusters were microdissected and subjected to site-specific single-cell RNA sequencing. Epithelial cell responses were evaluated in a coculture system using a neutralizing antibody. Finally, physiological relevance was assessed by in vivo depletion, followed by quantification of changes in saliva secretion. Saliva production was maintained or modestly increased during early aging stages and coincided with the emergence of lymphoid cell clusters. Single-cell and interactome analyses identified Gzma + ILC1 subsets enriched in aged lymphoid cluster regions and predicted crosstalk with epithelial cells via a GZMA–Pard3 axis. Upregulation of epithelial Aqp5 expression was confirmed in vitro. In vivo depletion of ILC1s in aged mice significantly reduced stimulated saliva output, indicating that local ILC1-derived GZMA supports secretory capacity. Aged submandibular salivary glands accumulated ILC1s that promote epithelial function through a GZMA-dependent pathway and increased AQP5 expression, thereby maintaining salivary secretion during early aging. These findings identify ILC1s as regulators of salivary gland homeostasis and highlight the GZMA–Pard3 axis as a potential therapeutic target.

Prioritizing causal variants in a regulatory region of the genome remains challenging. Here we introduce the Expression Modifier Score (EMS) v2, allowing prioritization of regulatory variants with high precision. EMSv2 achieves higher prediction performance compared to alternative methods, especially in tissues with low sample size such as brains. We show that the power gain is attributed to implementation of (1) features accounting for long-range DNA sequence interaction, (2) customization of loss-function in training, and (3) multi-task learning framework. We then apply EMSv2 to an independent eQTL data from a Japanese population to demonstrate that EMSv2 outperforms alternative methods in regulatory variant prioritization and can be utilized for functionally-informed fine-mapping in a distinct population. We also show that EMSv2 can be utilized in combination with the gene-level polygenic prioritization score (PoPS) to prioritize complex trait-causal regulatory variants. Our work accelerates regulatory variant prioritization in the human genome. Expression Modifier Score v2 integrates Enformer-derived features and multi-task learning to prioritize regulatory variants and support interpretation of noncoding genetic associations.

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) has become increasingly common, a trend driven by obesity, excess nutritional intake, and dysfunctional adipose tissue. While continuous dietary stress triggers adipose-tissue-derived lipotoxicity and disrupts hepatic metabolic homeostasis and provokes inflammation, the transcriptional scaffolds that mitigate this lipotoxicity remain incompletely understood. We investigated the role of zinc finger protein 90 (ZFP90) in defending against diet-induced metabolic stress and MASLD pathogenesis. Methods: Wild-type and ZFP90-knockout mice were subjected to a high-fat diet (HFD) to model nutrient-overload-induced MASLD. Hepatic phenotypes were characterized using metabolic profiling and RNA sequencing. Mechanistic dynamics were evaluated through protein interaction assays, and clinical relevance was validated using human MASLD liver biopsies. Results: ZFP90 deficiency significantly accelerated HFD-induced steatosis, systemic insulin resistance, and inflammatory infiltration. Crucially, ZFP90 depletion drove severe white adipose tissue (WAT) dysfunction, characterized by impaired lipogenic capacity, exacerbated lipolysis, and diminished local insulin signaling. This was accompanied by a pro-inflammatory secretory shift in WAT, evident from decreased Adipoq and increased Cd68/Ccl3 expression. In the liver, transcriptomic analysis revealed a profound induction of pathways related to fatty acid uptake and cytokine signaling. Mechanistically, ZFP90 forms a repressive complex with TRIM28, acting as a crucial molecular brake on NF-kB signaling. Loss of ZFP90 unleashes p65-mediated hyper-inflammation. Clinically, hepatic ZFP90 expression is significantly upregulated in patients with MASLD. Conclusions: ZFP90 is a novel regulator of immunometabolic homeostasis under dietary stress. By forming of complex with Trim28 to inhibit the nuclear translocation of NF-κB, ZFP90 suppresses pro-inflammatory responses and protects the liver from obesity-associated systemic lipotoxicity. These findings provide critical insights into the adipo-hepatic axis and highlight ZFP90 as a promising therapeutic target to mitigate the progression to metabolic dysfunction-associated steatohepatitis (MASH).

Recent studies identified that the dysregulation of fibroblast activity, in addition to impairment in epithelial integrity and uncontrolled immune response, is implicated in the pathogenesis of inflammatory bowel disease (IBD). The anti-inflammatory cytokine IL-10 and its receptors IL-10Rα and IL-10Rβ have IBD-associated single nucleotide polymorphisms. In the intestine, IL-10 signaling is essential for maintaining an anti-inflammatory state of myeloid cells and inducing regulatory T cells, thereby preventing intestinal inflammation linked to IBD development. However, its impact on the physiology and pathophysiology of intestinal fibroblasts is poorly understood. Here, we show that Il10ra deficiency leads to increased expression of a subset of genes in colonic fibroblasts, most of which are associated with the type I interferon (IFN) and type II IFN signaling pathways. In addition, Pdgfra-cre; Il10raf/f mice aged 16 weeks or older develop chronic spontaneous colitis and subsequent fibrosis accompanied by enhanced infiltration of myeloid cells and effector CD4+ T cells in the lamina propria of the colon. Moreover, Pdgfra-cre; Il10raf/f mice at 12 weeks of age exhibit more severe clinical symptoms than those of Il10raf/f mice during dextran sodium sulfate-induced colitis that can be suppressed by the administration of anti-IFNAR1 antibody but not anti-IFNGR1 antibody. Therefore, inhibition of type I IFN pathway via IL-10Rα signaling in fibroblasts is one of the IL-10-dependent mechanisms underlying the prevention of large intestinal pathology.

Although systemic allergen-specific IgE is an essential biomarker for allergic rhinitis (AR), its mechanistic contribution to symptom development remains unclear. Here, using mouse models, we investigated how systemic antigen-specific IgE influences AR symptoms and local type 2 inflammation. Mice were adoptively sensitized with ovalbumin (OVA)-specific IgE (OVA-IgE) and/or in vitro-differentiated OVA-specific Th2 (OVA-Th2) cells, followed by repeated intranasal OVA exposure. AR symptoms (sneezing) and the appearance of IgE-producing cells in the cervical lymph nodes (cLNs) and nasopharynx-associated lymphoid tissue were observed only in mice that received both OVA-Th2 cells and OVA-IgE. These responses were absent in recipients lacking factors required for IgE production, Rag2-/-, Aid-/-, and Stat6-/- mice, or in mice receiving OVA-Th2 cells deficient in IL-4-producing T follicular helper (Tfh) cell differentiation. Notably, when IgE-independent mast cell activation was induced by repeated intranasal administration of compound 48/80 in mice that had received OVA-Th2 cells, subsequent OVA challenge elicited OVA-specific AR symptoms and induced IgE-producing cells in the cLNs. Single-cell RNA sequencing revealed that systemic OVA-IgE facilitated the differentiation of OVA-Th2 cells into Tfh cells upon OVA challenge. Together, systemic IgE-mediated mast cell/basophil activation promoted Th2-to-Tfh differentiation and local IgE production, thereby contributing to the AR symptoms.

DNA ligase IV (LIG4) is essential for DNA double-strand break (DSB) repair. Hypomorphic LIG4 variants cause LIG4 syndrome, characterized by growth disturbance, increased radiosensitivity, predisposition to malignancies, adaptive immunodeficiency and inflammatory conditions. Most of these manifestations are recapitulated in hypomorphic LIG4 mutant mice. However, no model mice with defective DSB repair have consistently exhibited inflammation. Here, we have generated mutant mice carrying the LIG4 missense variant, p.W447C, found in a patient with LIG4 syndrome. Lig4W447C/W447C mice showed functional defects of LIGIV and manifested growth retardation, increased radiosensitivity, and life-threatening intestinal inflammation under severe adaptive immunodeficiency. The inflammation was dependent on lymphocytes and characterized by marked infiltration of Th1 cells and macrophages, along with elevated expression of IFN-γ-inducible genes. When Ifng was deleted, Th2 and Th17 instead of Th1 cells drove the inflammation. Single-cell RNA-seq analyses with TCR repertoire revealed that T cells from Lig4W447C/W447C mice preferentially used proximal Vα and Jα segments in V regions of TCRα chains and exhibited expansion of several clonotypes, a substantial portion of which were CD4 T cells expressing IFN-γ. Thus, our hypomorphic Lig4 mutant mice represent a unique model for studying Th1-skewed intestinal inflammation under severe adaptive immunodeficiency.

Background & Objectives: The increasing prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is intrinsically linked to nutrient overload and obesity, and adipose dysfunction. While continuous dietary stress triggers adipose-tissue-derived lipotoxicity and disrupts hepatic metabolic homeostasis and provokes inflammation, the transcriptional scaffolds that mitigate this lipotoxicity remain incompletely understood. We investigated the role of zinc finger protein 90 (ZFP90) in defending against diet-induced metabolic stress and MASLD pathogenesis. Methods: Wild-type and ZFP90-knockout mice were subjected to a high-fat diet (HFD) to model nutrient-overload-induced MASLD. Hepatic phenotypes were characterized using metabolic profiling and RNA sequencing. Mechanistic dynamics were evaluated through protein interaction assays, and clinical relevance was validated using human MASLD liver biopsies. Results: ZFP90 deficiency significantly accelerated HFD-induced steatosis, systemic insulin resistance, and inflammatory infiltration. Crucially, ZFP90 depletion drove severe white adipose tissue (WAT) dysfunction, characterized by impaired lipogenic capacity, exacerbated lipolysis, and diminished local insulin signaling. This was accompanied by a pro-inflammatory secretory shift in WAT, evident from decreased Adipoq and increased Cd68/Ccl3 expression. In the liver, transcriptomic analysis revealed a profound induction of pathways related to fatty acid uptake and cytokine signaling. Mechanistically, ZFP90 forms a repressive complex with TRIM28, acting as a crucial molecular brake on NF-κB signaling. Loss of ZFP90 unleashes p65-mediated hyper-inflammation. Clinically, hepatic ZFP90 expression is significantly upregulated in patients with MASLD. Conclusions: ZFP90 is a novel regulator of immunometabolic homeostasis under dietary stress. By forming of complex with Trim28 to inhibit the nuclear translocation of NF-κB, ZFP90 suppresses pro-inflammatory responses and protects the liver from obesity-associated systemic lipotoxicity. These finding provide critical insights into the adipo-hepatic axis and highlight the ZFP90 as a promising therapeutic target to mitigate the progression to metabolic dysfunction-associated steatohepatitis (MASH).