Cell reports最新文献

Despite the critical role of tumor-draining lymph nodes (TDLNs) in immunity, their heterogeneity is poorly understood. We employ single-cell and bulk RNA sequencing (RNA-seq) to dissect the immune landscape of TDLNs in colorectal cancer (CRC) cohorts. We reveal that enlarged TDLNs (L-TDLNs) are enriched with CD8⁺ effector T (Teff) cells exhibiting a distinct metallothionein (MT)-positive signature. CD8⁺MT⁺ Teff cells exhibit heightened cytotoxicity and a stress-adapted phenotype, which are critical mediators of anti-tumor immunity. CD8⁺MT⁺ Teff cells originate from L-TDLNs, where they undergo specific differentiation, and subsequently migrate to tumor. Moreover, patients with a high level of CD8⁺MT⁺ Teff cells in tumor show a significant survival advantage, in particular those treated with adjuvant chemotherapy. These findings highlight the importance of L-TDLNs in shaping effective anti-tumor immune responses, proposing the CD8⁺MT⁺ Teff cells as a prognostic biomarker and potential therapeutic target in CRC.

Monocyte-derived liver macrophages are critical in the pathogenesis of metabolic dysfunction-associated steatohepatitis (MASH) and liver fibrosis, but their recruitment mechanisms remain unclear. Serotonin (5-hydroxytryptamine [5HT]) is a conserved monoamine synthesized by tryptophan hydroxylase 1 (Tph1) in peripheral tissues and Tph2 in the brain. We show that, in mice housed at thermoneutrality and fed a high-fat, high-fructose diet, inhibition of peripheral serotonin (pe5HT) through genetic deletion of Tph1 prevents MASH independent of reduction in body weight. Liver flow cytometry and single-nucleus sequencing showed reduced pro-inflammatory Ly6C^high monocytes, monocyte-derived Kupffer cells (moKCs), and lipid-associated macrophages (LAMs) in Tph1 knockout (KO) mice. Tph1 deletion also decreased circulating monocytes, specifically Ly6C^high monocytes. A single 5HT injection increased Ly6C^high monocytes, while Tph1 KO mice had reduced monocytes without affecting bone marrow monocytes. Mechanistically, serotonin inhibition increases liver AMP-activated protein kinase (AMPK) activity, and this is important for reducing CCL2 and monocyte recruitment. These findings link two ancient energy sensors, 5HT and AMPK, with obesity-associated liver fibrosis.

Axons of dopaminergic neurons express gamma-aminobutyric acid type-A receptors (GABA_ARs) and nicotinic acetylcholine receptors (nAChRs), which are positioned to shape striatal dopamine release. We examine how interactions between GABA_ARs and nAChRs influence dopaminergic axon excitability. Axonal patch-clamp recordings reveal that potentiation of GABA_ARs by benzodiazepines suppress dopaminergic axon responses to cholinergic interneuron transmission. In imaging experiments, we use the first temporal derivative of axonal calcium signals to distinguish between direct stimulation of dopaminergic axons and nAChR-evoked activity. Inhibition of GABA_ARs with gabazine selectively enhance nAChR-evoked axonal calcium signals but does not alter the strength or dynamics of acetylcholine release, suggesting that the enhancement is mediated primarily by GABA_ARs on dopaminergic axons. Unexpectedly, we find that a widely used GABA_AR antagonist, picrotoxin, inhibits axonal nAChRs and should be used cautiously for striatal circuit analysis. Overall, we demonstrate that GABA_ARs on dopaminergic axons regulate integration of nicotinic input to shape axonal excitability.

The signaling scaffold CARD11 is critical for adaptive immunity and antigen receptor signaling to canonical nuclear factor κB (NF-κB), mTOR, JNK, and AKT. Oncogenic gain-of-function (GoF) CARD11 mutants, implicated in a variety of lymphomas, bypass regulation and signal constitutively. In mice expressing the lymphoma-associated mutation CARD11 C49Y, we observe B cell expansion that is most impressive for marginal zone (MZ) B cells. CARD11^C49Y/C49Y MZ B cells exhibit enhanced cell-autonomous survivability and elevated basal levels of the precursor NF-κB subunit p100, which is inducibly processed, leading to elevated nuclear p52 levels in response to B cell activating factor (BAFF). We show that active CARD11 variants can inhibit basal NIK-induced p100 processing to p52 independently of their ability to activate canonical NF-κB. Our results reveal an unexpected ability of activated CARD11 to potentiate the noncanonical NF-κB pathway through p100 accumulation, which likely contributes to both normal B cell homeostasis and the dysregulated proliferation of lymphomas that harbor CARD11 GoF variants.

FoxP3, the master regulator of Tregs, employs two DNA-binding modes to recognize diverse DNA sequences. It multimerizes on long TnG repeats (n = 2-5) to bridge DNA segments and stabilize chromatin loops, and it forms head-to-head (H-H) dimers on inverted repeat forkhead motifs (IR-FKHM) without bridging DNA. Although genomic data confirm its multimeric role, in vivo evidence for H-H dimerization has been elusive. Here, unbiased pull-down sequencing uncovers a range of relaxed motifs that drive H-H dimerization, enabling systematic genome-wide analysis. We demonstrate that FoxP3 binds genomic DNA as both H-H dimers and multimers in Tregs, with H-H binding often seeding and stabilizing multimerization on adjacent TnG repeats-especially on shorter, suboptimal repeats. While multimerization is conserved across FoxP family members, H-H dimerization is unique to FoxP3 orthologs, conferred by its divergent accessory loop. This dual-mode strategy broadens FoxP3's sequence repertoire and enhances its architectural function in chromatin looping.

PIEZO ion channels generate force-induced macroscopic currents that rapidly inactivate but display repetitive single-channel opening and closing under steady membrane tension. The mechanism underlying these gating characteristics remains unresolved. In the force-induced flattened state of PIEZO1, its top cap domain swings between up and down states via the spring-like extension and compression of the connecting linkers, driving the opening and closing of the pore. We identify that the linkers and key residues contribute to the activation and inactivation of the macroscopic current, as well as to the open dwell time and conductance of the single-channel current. Steered molecular dynamics simulations reveal that the linkers behave like entropic springs, whose elastic energy matches the steady-state single-channel gating energy. Taken together, we propose that the linkers function as compressive entropic springs to store and release energy upon their compression and extension, which drives activation, inactivation, as well as stochastic single-channel gating of PIEZO channels.

The heterogeneity of conventional dendritic cells type 1 (cDC1s) and type 2 (cDC2s) is well established, yet the identity and origin of CD301b⁺ cDC2s remain debated. Here, we show that CD301b⁺ cDC2s and CD103⁺ cDC1s develop from pre-committed progenitors in response to granulocyte/macrophage colony-stimulating factor (GM-CSF). While CD103⁺ cDC1s acquire their phenotype and functional properties through GM-CSF-driven differentiation from pre-cDC1s, CD301b⁺ cDC2s emerge as cytokine-induced states from DC2- and DC3-committed progenitors. CD103⁺ cDC1s and CD301b⁺ cDC2s exhibit enhanced T cell priming capacities and distinct cytokine expression profiles upon GM-CSF exposure. In vivo, DC-intrinsic GM-CSF sensing is dispensable for acquiring CD103 and CD301b expression with the notable exception of lung DCs, while specific type 2 cytokines induce CD103 and CD301b ex vivo. These findings identify GM-CSF and specific type 2 cytokines as central regulators of cDC1 and cDC2 effector differentiation and establish CD301b as a marker of a cytokine-driven cDC2 state.

Cells remodel their proteomes in response to changing environments by coordinating protein synthesis and degradation. In yeast, degradation occurs via proteasomes and vacuoles, with bulk and selective autophagy supplying vacuolar cargo. Although these pathways are known, their relative contributions to proteome-wide remodeling remain unreported. To assess this, we developed a method (nPL-qMS) to pulse-label the methylotrophic yeast Komagataella phaffii (Pichia pastoris) with isotopically labeled nutrients that, when coupled to quantitative proteomics, enables global monitoring of protein degradation following an environmental perturbation. Genetic ablations revealed that autophagy drives most proteome remodeling upon nitrogen starvation, with minimal non-autophagic contributions. Cytosolic protein complexes, including ribosomes, are degraded through bulk autophagy, whereas degradation of peroxisomes and mitochondria uses selective autophagy. Notably, these pathways are independently regulated by environmental cues. Our approach expands known autophagic substrates, highlights autophagy's major role in fungal proteome remodeling, and provides rich resources and methods for future proteome remodeling studies.

Regulatory T cells (Tregs) play important immunosuppressive and tissue-regenerative functions in skin. A subset of Tregs localizes to hair follicles (HFs), where they promote hair growth through activation of HF stem cells. However, the mechanisms driving Treg accumulation in HFs remain to be identified. We find that Tregs utilize Cxcr4 to accumulate in HF epithelium and that its expression is partially dependent on glucocorticoid receptor signaling. Additionally, we show that Cxcl12, the main cognate ligand of Cxcr4, is enriched in keratinocytes of the upper HF and that disruption of the Cxcr4-Cxcl12 axis results in suboptimal hair growth. Finally, we demonstrate that upper HF keratinocytes in human skin express Cxcr4 ligands in a pattern similar to that in murine skin. Collectively, these results reveal an evolutionary conserved pathway of Treg trafficking within a barrier tissue that promotes hair regeneration, which may have implications for immunotherapeutic modulation of human alopecia.

The Qinghai-Xizang Plateau (QXP), harboring the planet's highest density of plateau lakes, offers an exceptional biogeographic environment for studying extremophilic microbial communities and their adaptation to salinity. Through deep metagenomic sequencing, we construct the Qinghai-Xizang Lake Sediment Genome (QXLSG) catalog, a high-resolution genomic catalog comprising 5,866 metagenome-assembled genomes (MAGs), 58.16 million non-redundant protein encoding genes, and 19,008 biosynthetic gene clusters. Notably, 80.78% of the 2,742 species-level MAGs represent undescribed taxa, significantly expanding the known microbial diversity. Salinity emerges as the primary environmental factor influencing microbial community. Functional annotation highlights that the "salt-out" strategy, particularly the uptake of glycine betaine, is the main mechanism for salinity tolerance. This strategy is prevalent in both hypersaline lake communities and the dominant microbial phyla. Overall, this study provides a crucial genetic resource for future bioprospecting and deepens our understanding of the fundamental mechanisms of microbial adaptation to extreme saline environments.