Using genomic approaches, Faiola et al.1 evaluated the Streptococcus pyogenes carriage state, and pre- and post-treatment pharyngitis, directly from human subjects. This work suggests that carriage isolates may evolve with host-specific mechanisms rather than a unified regulatory phenotype.
Ran et al. identify a heart-associated origin of mouse supraclavicular brown adipose tissue (BAT). Their findings challenge the dominance of interscapular BAT in mouse research and suggest that anatomically corresponding depots may better inform translation to human thermogenic fat.
Disruption of circadian glucocorticoid (GC) rhythms is associated with chronic stress and obesity, yet its metabolic signature remains poorly defined. Using a physiological mouse model, we show that the liver is largely protected from pathological steatosis despite profound obesity and hyperinsulinemia. We identify a unique redistribution of insulin resistance: rhythm disruption does not globally impair insulin action as occurs in diet-induced obesity. Instead, skeletal muscle develops severe insulin resistance while adipose and hepatic tissues remain functionally insulin responsive. This preserved sensitivity allows the adipose tissue to act as a metabolic reservoir, utilizing sustained hyperinsulinemia to sequester lipids and shield the liver from toxic fatty-acid flux. These findings reveal that GC-rhythm disruption uncouples obesity from hepatic steatosis by redistributing insulin action from skeletal muscle to adipose tissue and liver. Thus, GC-rhythm disruption and high-fat diet are independent and additive drivers of adiposity with divergent hepatic effects.
Chronic, non-healing wounds are sustained by Staphylococcus aureus biofilms, yet how biofilm reprograms the immune cells tasked with resolving injury has remained unclear. We show that biofilm-derived soluble cues, not bacterial contact, generate a previously undescribed biofilm-associated macrophage (BAM) subset marked by high Macrophage receptor with collagenous structure (MARCO) and suppressed MERTK, which recognizes apoptotic cells but fails to engulf them. Using isogenic S. aureus USA300 variants of graded biofilm capacity, only high biofilm-conditioned medium elicited this state in human macrophages; MARCO neutralization restored corpse clearance. Mechanistically, biofilm factors drove phospho-C/EBPβ into the nucleus to repress MERTK, severing sensing from engulfment. Single-cell and Xenium spatial transcriptomics, with cytometry by time of flight (CyTOF) and PhenoCycler, localized BAMs to biofilm-proximal niches as a hybrid CD64+CD163+ state outside M1/M2 categories, populating 60%-80% of infected chronic wounds. In vivo, myeloid-restricted MARCO overexpression by tissue nanotransfection recapitulated impaired efferocytosis and persistent inflammation, nominating MARCOhiMERTKlo macrophages as a druggable checkpoint in biofilm-associated disease.
Many cancers are driven by mutationally altered transcription factors (TFs) that rewire cells to an oncogenic state. Cells must activate specific mechanisms to tolerate the burden of oncogenic TF activity. To define such mechanisms, we focused on a canonical oncogenic fusion protein-driven cancer, alveolar rhabdomyosarcoma (ARMS), where the PAX3::FOXO1 fusion protein hyperactivates and mislocalizes PAX3 and FOXO1 TF functions. Employing sequential functional genomic CRISPR-Cas9 screens, we identified FANCM, a DNA translocase in the Fanconi anemia pathway, as a selective dependency in PAX3::FOXO1+ ARMS. FANCM loss reduces fusion protein levels, induces myogenic differentiation, and disrupts the PAX3::FOXO1 transcriptional program, thereby halting oncogenic proliferation. Mechanistically, FANCM depletion exacerbates replication stress (RS) and DNA damage signaling, with chromatin-associated RS enriched at PAX3::FOXO1 target gene loci, resulting in selective downregulation of the oncogenic program. CRISPR exon-tiling screens prioritized FANCM’s helicase and DNA-binding domains as essential for this dependency, linking FANCM-mediated replication fork binding to sustained oncogenesis.
Memory CD8 T cells provide durable protection against recurrent infection and cancer, but how individual TCR clonotypes contribute to distinct memory fates remains enigmatic. Here, we analyzed 242 murine CD8 TCRαβ clonotypes specific for an influenza NP366-374/H-2Db ligand (pMHC) by integrating single-cell transcriptomics and paired TCR sequencing with force-dependent biophysics, structural analysis, and in vivo retrogenic validation. Within this shared antigenic and inflammatory setting, clonotype identity was associated with central memory, effector memory, or bipolar transcriptional outcomes. Structural and biophysical analyses of representative TCRs revealed differences in Vα-centric versus Vβ-centric pMHC engagement and in atomistic contacts that are consistent with altered force transmission through the TCR. These interaction modes correlated with CD3ζ phosphorylation, memory transcriptional programs, clonal expansion, and heterosubtypic crossreactivity. Thus, TCR clonotypes appear to encode not only antigen specificity but also differing propensities for memory differentiation, supporting a model in which TCR-pMHC mechanochemistry contributes to CD8 memory fate.
Phosphoantigen (pAg) recognition by Vγ9Vδ2+ T cells plays a critical role in immunity to pathogens and cancer. The butyrophilin (BTN) family of molecules have emerged as key regulators of γδ T cells; however, the underlying mechanisms remain unclear. Here, we demonstrate an interaction between BTN3A1 and Vγ9Vδ2+ T cell receptor (TCR) in a cell-free assay, confirming that BTN3A1 is a direct ligand for the Vγ9Vδ2+ TCR. Furthermore, immobilized recombinant BTN2A1 plus BTN3A1 extracellular domains are sufficient to activate Vδ2+ T cells. Finally, we show that intracellular pAg accumulation can modulate binding of Vγ9Vδ2+ TCR in a BTN3A1-dependent manner, indicating the important role of TCR binding to BTN3A1 in pAg recognition. These data confirm that BTN3A1, in conjunction with BTN2A1, is a direct ligand for Vγ9Vδ2+ TCR, providing the key interactions required for pAg recognition.
To move through the world, animals extract visual features from objects. Although the dorsomedial striatum (DMS) contains visual processing circuits, visual perception is considered a cortical attribute. Here, we asked whether neurons from the DMS encode visual features in the absence of behavioral contingencies contributing to visual perception. Using electrophysiological recordings of spiny projection neurons (SPNs) located in a target region of the primary visual cortex, we identified visually responsive neurons. A low percentage of SPNs were orientation selective. However, different orientations of drifting-gratings were predicted by populations of non-orientation-selective neurons. Striatal visual responses were more transient and less accurate than cortical responses, indicating distinctive visual processing by striatal circuits. SPNs from the direct and indirect pathways participated in visual processing. Pathway-specific silencing of SPNs revealed that intra-striatal connectivity shapes visual processing, defining striatal visual modules. These findings indicate visual processing by the DMS, expanding current models of visual perception and basal ganglia functions.
Type IV-C CRISPR-Cas systems remain enigmatic compared to other class 1 systems. Here, we expand the type IV-C catalog, identifying two phylogenetically distinct clades primarily found in archaea (IV-C1) or bacteria (IV-C2), distinguishable by the Cas10IVc subunit architecture. We functionally and structurally characterize type IV-C1 systems from Thermococcus onnurineus (Ton) and Pyrococcus abyssi (Pab). Type IV-C complexes assemble with crRNAs derived from distinct CRISPR arrays and recognize a 5'-GGG-3' protospacer adjacent motif (PAM) to bind double-stranded DNA targets. Target recognition activates the HD domain of Cas10IVc, triggering metal-dependent collateral cleavage of single-stranded DNA and RNA. This behavior is explained by allosteric alignment of the HD active site, triggered by PAM-dependent R-loop formation, as revealed by cryo-EM. Together, our findings suggest that type IV-C systems provide immunity via non-specific cleavage of nucleic acids generated during mobile genetic element replication or transcription.
Sex-dimorphic adipose mitochondrial function (lower activity in males) correlates with visceral adiposity and metabolic risk, yet the underlying mechanisms remain elusive. We find that androgen-androgen receptor (AR) signaling suppresses mitochondrial respiration and thermogenesis in visceral adipose tissue (VAT), promoting visceral fat accumulation. Mechanistically, androgen-AR signaling represses transcription of Pdhb, which encodes a pyruvate dehydrogenase (PDH) subunit, thereby reducing PDH activity, acetyl-CoA levels, H3K27 acetylation, and chromatin accessibility at the promoters of mitochondrial respiration-related genes. Notably, Pdhb overexpression largely reverses these alterations and restores mitochondrial function. Furthermore, sodium dichloroacetate, a PDH activator, enhances mitochondrial respiration and reduces visceral fat in male mice. Multi-omics analyses reveal that the androgen-PDH axis orchestrates a male-specific chromatin-based transcriptional landscape that encompasses mitochondrial and metabolic pathways in visceral adipocytes. Collectively, this study identifies the androgen-PDH axis as a key regulator of sexual dimorphism in mitochondrial metabolism and adipose homeostasis in VAT.
Autoreactive T cells that destroy beta cells in type 1 diabetes are largely targeting insulin signal peptide fragments. HLA knockout beta-cells have been proposed to create hypo-immune cells, but this strategy poses significant tumorigenic risks. Alternatively, we hypothesized that insulin signal peptide modification would give rise to beta cells evading autoimmune recognition while maintaining insulin functionality. We developed human beta-cell lines lacking endogenous insulin and complemented them with insulin-carrying signal peptides from different hormones including chromogranin-A. We evaluated insulin synthesis, processing, secretion, activity, and immune evasion. Chromogranin-A signal peptide substitution directed insulin expression, maturation, and secretion, maintaining physiological proinsulin/insulin ratios. Secreted insulin remained functional. Crucially, beta cells expressing insulin with chromogranin-A signal peptide evaded recognition and killing by autoreactive T cells without inducing ER stress or compromising cellular identity. This approach may offer a targeted alternative to systemic immunosuppression to be used in stem-cell-derived therapies by engineering endogenous insulin signal peptide.
The tumor microenvironment (TME) domesticates macrophage function by decreasing chromatin accessibility. The activation and nuclear translocation of ATP-citrate lyase (ACLY) convert citrate to acetyl-CoA, providing a substrate necessary for histone acetylation. However, the underlying mechanisms in macrophage remodeling are poorly understood. Here, we found that saturated fatty acids (sFA), especially palmitic acid (PA), were lower in TAMs of patients with hepatocellular carcinoma (HCC). Scd1 knockout promoted PA accumulation, resulting in both primary and metastatic liver cancer retardation and overall survival improvement. Mechanisms indicated that ACLY-C893 palmitoylation via PA maintained tetramer stability against CUL3-mediated degradation, facilitating histone acetylation of M1-related genes. Notably, both dietary PA with Scd1KO macrophage infusion and TAM-targeted in vivo PA/shSCD1 reprogramming improved the TME to repress HCC progression. Collectively, our research highlights the crucial role of ACLY palmitoylation in the connection between macrophage FA metabolism and histone acetylation reprogramming, which sheds light on the strategy of macrophage-based HCC immunotherapy.
Metabolic alterations are increasingly recognized during influenza virus infection, but how local lactate accumulation shapes antiviral immunity remains poorly characterized. By integrating time-series targeted energy metabolomics, single-cell RNA sequencing, flow cytometry, and functional perturbation, we show that influenza virus infection preferentially increases lactate within the lung microenvironment, where it restrains pulmonary CD8+ T cell response. Mechanistically, extracellular lactate enters dendritic cells through monocarboxylate transporter (MCT)-dependent transport and induces a tolerogenic-like state marked by impaired maturation, reduced costimulation, and diminished CD8+ T cell-priming capacity. Direct experimental evidence identifies H3K18la as a prominent lactate-responsive histone lactylation mark, while multi-omics integration links it to enhancer accessibility and NRF2 pathway activation. Functional studies further show that NRF2 promotes dendritic cell suppression by reinforcing tolerogenic programs and limiting mtROS-dependent XBP1 splicing. Together, these findings reveal a lactate-driven histone lactylation-NRF2 pathway that modulates antiviral immunity during influenza infection.
Loss of major histocompatibility complex class I (MHC-I) molecules from the tumor cell surface is a common mechanism of immune evasion; yet, the receptor intrinsic events that initiate their endocytic removal remain unclear. Here, using HLA-A∗11:01, a human MHC-I heavy chain allotype as a model, we identify a membrane responsive regulatory module within its cytoplasmic tail. The conserved 360-365 segment engages phospholipid membranes and undergoes Cys363-dependent self-association under membrane mimetic conditions, while cooperating with the transmembrane region to shape the molecular proximity of full-length HLA-A. Disruption of this segment weakens association with the trafficking GTPase ARF6, slows receptor internalization, and prolongs HLA-A retention at the cell surface. Consistently, a cell penetrating peptide containing this sequence limits endogenous HLA-A internalization across several tumor cell lines. These findings identify the HLA-A cytoplasmic tail as an active regulator of endocytic trafficking and suggest a strategy for preserving surface HLA-A availability in tumor cells.
The molecular basis of neutrophil-driven immunopathology in severe coronavirus disease 2019 (COVID-19) remains poorly defined. Here, we identify the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) SARS-unique domain (SUD)2core domain as a direct binding partner of the neutrophil-associated protein heme binding protein 2 (HEBP2). We show that HEBP2 normally suppresses azurophilic granule exocytosis, whereas SUD2core recruits the E3 ligase LTN1 to ubiquitinate and degrade HEBP2, thereby activating the Rab27a-Synaptotagmin Like 1 (SYTL1) axis to promote granule release, NETosis, and pro-inflammatory cytokine secretion. In a human immuno-epithelial organoid co-culture model, SUD2core amplifies epithelial damage in an HEBP2-dependent manner. Importantly, two small-molecule compounds that disrupt the SUD2core-HEBP2 interaction effectively attenuate neutrophil-mediated inflammation. These findings reveal a viral strategy that dismantles host restraint on neutrophil effector functions and highlight the SUD2core-HEBP2 interface as a promising therapeutic target for COVID-19.
Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer; however, its prognosis remains poor, and the underlying molecular mechanisms have yet to be fully elucidated. In this study, a prognostic model was constructed based on manganese metabolism-related genes, which effectively stratifies patients with LUAD with different prognoses and drug sensitivity. Mendelian randomization analysis identified glutathione peroxidase 3 (GPX3) as a key prognostic gene, which was downregulated in LUAD and significantly correlated with favorable outcomes. Functionally, GPX3 was found to inhibit LUAD cell proliferation, invasion, and metastasis while promoting apoptosis. Mechanistically, GPX3 binds to heat shock protein β-1 (HSPB1), induces its ubiquitination, and facilitates its degradation, thereby activating the Hippo signaling pathway and suppressing malignant phenotypes in LUAD cells. In summary, this study not only established a robust prognostic model based on manganese metabolism-related genes but also uncovered the critical regulatory role of the GPX3/HSPB1/yes-associated protein (YAP) axis in LUAD progression, underscoring the therapeutic potential of targeting GPX3.
Neuroinflammation often disrupts cerebral cholesterol homeostasis and leads to white matter damage and demyelination. However, the molecular mechanisms underlying these defects have remained enigmatic. In this study, we report that inflammation is associated with aberrant activation of Wnt signaling in astrocytes. While Wnt signaling increases astrocytic expression of SREBF2 protein and intracellular cholesterol level, it simultaneously inhibits the expression of APOE and reduces cholesterol efflux from astrocytes. The extracellular cholesterol supply is essential for the activation of the expression of MYRF transcription factor and myelin-associated genes in oligodendrocytes. Moreover, the defective oligodendrocyte differentiation and myelin gene expression caused by astrocytic Wnt activation in transgenic mice can partially be rescued by chemical-enhanced ApoE expression. Our findings suggest a regulatory pathway of “inflammation → Wnt signaling → cholesterol metabolism → myelin integrity” and provide important insights into the molecular mechanisms underlying inflammation-induced demyelinating diseases and future therapeutic strategies.
Diabetic complications, including retinopathy, are driven by hyperglycemic metabolic reprogramming and aberrant angiogenic transcription. Recent work highlights lactate accumulation and protein lactylation as key regulators, yet their underlying mechanisms in diabetic retinopathy remain unknown. Here, we report that hyperglycemia triggers aminoacyl-tRNA synthetase 1 (AARS1)-mediated lactylation of histone deacetylase 1 (HDAC1) at lysine 412. This modification sequesters HDAC1 in the cytoplasm, preventing its nuclear translocation and abrogating deacetylation of H3K56. The consequent H3K56ac increase activates transcription of the angiogenic gene vascular endothelial growth factor A (VEGFA). Disruption of the HDAC1 K412 lactylation impairs vascular morphogenesis and causes embryonic lethality in zebrafish, whereas Hdac1-K412A knockin mice are protected from pathological retinal angiogenesis in an STZ-induced diabetic model. Pharmacologically, the small molecule exifone inhibited HDAC1 lactylation, suppressing aberrant angiogenesis in diabetic mice and impairing vascular development in chick embryos. Our findings establish HDAC1 lactylation as a critical metabolic-epigenetic switch and a promising therapeutic target.
Many HIV-1 broadly neutralizing antibodies (bnAbs) account for envelope (Env) glycan shielding by supplementing antibody-protein interactions with antibody-glycan interactions. Further, bnAbs that interact predominantly via glycans can augment their binding through antigen-binding fragment (Fab) dimerization, generally utilizing non-variable region interactions. Here, we examined a donor whose serum identified glycan-reactivity (antibody 2G12-like) and CD4 binding-site (CD4bs) reactivity and isolated both glycan-reactive and CD4bs-reactive antibodies. The CD4bs antibodies were members of the VRC01-antibody class and neutralized nearly 70% of HIV-1 (208-strain panel). The glycan-reactive antibody had ∼30% breadth, and cryo-EM analysis revealed it to be a Fab-dimerized glycan (FDG)-reactive antibody with a distinct architecture wherein the Fab arms dimerized through a disulfide bond at the tips of the complementarity-determining loops that wedged between two glycans. Overall, we identified an FDG antibody that recognized through a “dual-glycan clamp” epitope and is the second FDG antibody to be isolated from an HIV-infected donor since antibody 2G12.
