Browse Articles

Potential Roles of Mirtron-5010 in Tumor Stemness and Immune Regulation 2308336

Abstract Introduction Despite advances in treatment, invasive breast cancer remains among the deadliest cancers in women, driven by limited therapeutic options that precisely target their molecular drivers. Mirtrons, an emerging class of intron-derived microRNAs, may represent unrecognized regulators of tumor progression and invasion. This study examines how mirtron-5010 influences cancer stemness and iron accumulation in triple negative MDA-MB-231 breast cancer. Methods MDA-MB-231 bulk and stem cell populations were engineered to upregulate mirtron-5010. Classical stemness markers (SOX2, OCT4, NANOG, and KLF4) as well as the regulatory subunit PPP2R2D, were analyzed using quantitative PCR and immunohistochemistry. Intracellular iron levels were measured using FerroOrange fluorescence quantification. Results Across bulk cultures, mirtron-5010 upregulation elevated SOX2, OCT4, and NANOG expression, indicating enhanced stem-like characteristics. When looking into tumor stem cell population, mirtron-5010 upregulation further increased SOX2 and NANOG expression. Consistent with this, both bulk and tumor stem cells with mirtron-5010 upregulation showed greater labile iron pool determined by FerroOrange fluorescence, signifying an altered preference in iron metabolic pathways than controls. Interestingly, the subunit PPP2R2D of the PP2A enzyme complex was downregulated in mirtron-5010 upregulated cells. Conclusion In conclusion, mirtron-5010 enhances stemness and promotes iron accumulation in invasive breast cancer cells, highlighting its potential as a molecular target for therapy-resistant subtypes. Through modulation of the PP2A enzyme complex, mirtron-5010 also dampens IL-2—driven T-cell activation and proliferation, suggesting a role in shaping the tumor immune microenvironment. Future studies will further delineate the functional consequences of mirtron-5010 expression in both cancer and immune cell contexts across diverse breast cancer models. Funding Source NIGMS (R16GM153648) Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

In Situ‐Constructed Elastomeric Interphase for Grain Boundary Stabilization in High‐Voltage Layered Oxide Cathodes

ABSTRACT Layered oxide cathodes are a leading class of high‐energy‐density electrode materials for lithium‐ion batteries, but their long‐term stability at high voltages is compromised by chemical corrosion and mechanical stress at grain boundaries. Here, we report the construction of an elastic and voltage‐tolerant poly(urea‐siloxane) (PUSi) coating via the in situ polymerization of amine‐terminated polydimethylsiloxane and toluene diisocyanate (TDI). This polymer acted as a conformal artificial interphase that stabilized the secondary‐particle surface and internal primary‐particle surfaces. The PUSi layer acted as a stable chemical barrier that isolated cathode interfaces from direct contact with the electrolyte. This suppressed interfacial side reactions and inhibited the layered‐to‐spinel phase transformation. The tailorable elasticity of the PUSi layer allowed it to accommodate cyclic volumetric variations and suppress intergranular cracking during high‐voltage cycling. When applied to LiNi 0.6 Co 0.2 Mn 0.2 O 2 , the cathode showed a capacity retention of 81.2% after 450 cycles in coin cells and 82.4% after 200 cycles in Li‐metal pouch cells under a cut‐off voltage of 4.5 V. The generality of this approach was demonstrated by using it to coat LiNi 0.8 Co 0.1 Mn 0.1 O 2 and lithium‐rich layered oxides. This work provides a scalable and eco‐friendly route for engineering grain boundaries and interfacial stability in high‐energy cathode systems.

Circulating inflammatory biomarkers and antifungal susceptibility in Candida albicans vulvovaginal candidiasis: a retrospective observational cohort study

CMKLR1 as a potential target of cardiometabolic disease in PLWH 2267392

Abstract Introduction People living with HIV (PLWH) are at a greater risk of developing cardiometabolic diseases, including diabetes, compared with people without HIV (PWoH). Chemerin (RARRES2), regulates immunity and metabolism through its receptors CMKLR1 and CCRL2. We hypothesized that chemerin—CMKLR1 signaling is dysregulated in PLWH, contributing to metabolic disease. Methods We analyzed chemerin in the adipose tissue from 59 PWH (20 non-diabetic, 19 prediabetic, and 20 diabetic) in the HATIM cohort. Single-cell transcriptomic analysis was used to compare CMKLR1 expression based on HIV status and to identify differential gene expression in smooth muscle cells. Results CMKLR1 was highly expressed in stromal/myeloid cells, while RARRES2 was expressed in preadipocytes and vascular smooth muscle cells. Macrophage CMKLR1 expression was increased in PLWH with diabetes (P = 0.0002) compared to PWoH with diabetes, while CCRL2 trended higher (P = 0.09). Communication analysis showed HIV shifts signaling from structural/homeostatic pathways (COLLAGEN, CD99, ANNEXIN) toward inflammatory/metabolic axes (CHEMERIN, GAS6, ICAM). In the CHEMERIN pathway, preadipocytes predicted as the dominant senders. Intermediate macrophages and myofibroblasts were the principal receivers. Conclusion Chemerin—CMKLR1 signaling is upregulated in PLWH, particularly within inflammatory macrophages, suggesting enhanced immune—stromal crosstalk that may underlie the heightened risk of diabetes and cardiometabolic disease in this population. Funding Source n/a Topic Categories Immune Mechanisms of Human Disease (HUM)

MDSC-Mediated Regulation of Th9 and CD8+ T Cells Orchestrates Neurocognitive Pathology in Experimental Cerebral Malaria 2308438

Abstract Introduction Cerebral malaria (CM), a catastrophe of Plasmodium infection, is driven by skewed host immune responses and is coupled with lasting cognitive impairment. IFN-γ and Granzyme B—mediated neuroinflammation contributes to neuronal injury, yet the immune—metabolic mechanisms coupling myeloid regulation to neurotransmitter imbalance remain unclear. This study investigates the reciprocal interaction of myeloid-derived suppressor cells (MDSCs) and Th9 cells during experimental cerebral malaria (ECM), and how this immune axis disrupts dopamine homeostasis, BDNF signaling, and COMT regulation. Methods ECM was induced in rodents using Plasmodium berghei ANKA. MDSC and Th9 populations were analyzed by flow cytometry. IL-9 neutralization and MDSC were depleted in vivo to assess reciprocal regulation. IFN-γ and Granzyme B levels, dopamine content, BDNF expression, COMT regulation, and glial activation were quantified by flowcytometer, HPLC and qRT-PCR. Results IL-9 elevated expansion and pro-inflammatory programming of MDSCs, particularly PMN-MDSCs. MDSCs, through IL-1β secretion, promoted Th9 differentiation, forming a feed-forward loop. Depleting IL-9 during ECM reduced MDSC proliferation and activation, while depleting MDSCs subverted Th9 frequency. Increased IFN-γ and Granzyme B from CD8+ T cells impeded dopamine synthesis via oxidative stress, tyrosine hydroxylase suppression, and dopaminergic neuronal injury. Dopamine loss impaired BDNF transcription and induced maladaptive COMT upregulation. Conclusion Our study established IL-9—MDSC—Th9 immune axis as a core driver of neuroinflammation and dopamine dysregulation during ECM. Immune-mediated disruption of dopamine—BDNF—COMT signaling provides a mechanistic link between inflammation and cognitive dysfunction, highlighting IL-9 as a potential adjunct therapeutic target in cerebral malaria. Funding Source ICMR (Sanction No: EMDR/SG/15/2023-1532 Dated: 04.04.2024) Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

Factors governing CD8+ resident memory (Trm) cell retention and migration in tumors and draining lymph nodes 2260863

Abstract Introduction CD8+ resident memory (Trm) cells are critical mediators of anti-tumor immunity. However, it remains unclear whether canonical memory T cell features, namely antigen independence and durable persistence, apply to Trm cells that persist amid chronic antigen exposure in tumors and tumor draining lymph nodes (TDLNs). A better understanding of these features will allow us to interpret durable responses against cancer, while advancing our fundamental knowledge of Trm biology. Methods We employed the B2905 (M4) mouse melanoma model and inducible TCR-alpha knockout mice to assess whether antigen engagement is required for CD103+CD69+ Trm cell retention within the tumor and the TDLN. Xenium spatial transcriptomics was used to define patterns of Trm cell localization within these tissues. Mice expressing the KAEDE photoconvertible marker were used to track Trm cell egress from tumors. Results The retention of Trm cells within tumors occurred independently of antigen engagement, whereas antigen recognition was required for Trm persistence within TDLNs. Spatial transcriptomics further supported this conclusion, as melanoma antigen-specific CD8 T cells localized in regions lacking cognate antigen exhibited a stronger Trm transcriptional signature than those in antigen-expressing areas. Tracking T cell migratory dynamics, we found that Trm cells are less likely to migrate from the tumor to the TDLN than non-Trm cells. Conclusion These studies establish that intratumoral Trm cells, like canonical memory T cells, persist and are maintained in an antigen-independent manner, whereas Trm cells in TDLNs are antigen-dependent. Additionally, we found that differential T cell — antigen localization patterns within tumors may affect their Trm characteristics. Ongoing studies will determine how the spatial proximity to antigen governs Trm cell retention, migration, and their capacity to protect against metastatic disease. Funding Source NCI R01 CA225028 and R01 CA120777. Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

N-acetyl Aspartate Induces a Pro-Inflammatory Phenotype in Peritoneal Resident Macrophages, Driving Metabolic and Transcriptional Changes 2309239

Abstract Introduction Peritoneal cavity (PC) tissue resident macrophages (TRM) are key players in immune defense and tissue homeostasis. The metabolite N-acetyl aspartate (NAA) is elevated in the PC. NAA is synthesized from acetate and aspartate by Nat8l and metabolized back to aspartate by Aspa. TRM depend on their tissue niche, PC TRM uniquely express Aspa, and NAA levels are associated with worse outcomes in ovarian cancer patients suggesting NAA is key in the biology of the PC. Methods The PC niche was examined by phenotype, metabolomics, 13C carbon tracing and single cell RNA sequencing in wild type and Aspa-/- or Nat8l-/- mice. In addition, multiple type 2 inflammatory models and orthotopic tumor models carried out in vivo and macrophage responses to NAA assessed in vitro. Results We reveal the expression of Nat8l by PC TRM, indicating the NAA metabolic loop can run within the PC. Moreover, PC NAA levels are dynamic in type 2 mouse models, however, there is low incorporation of metabolized NAA-derived aspartate into the TCA cycle. In vitro, NAA alters the intracellular metabolome and increases metabolic rates. These metabolic changes are also seen in vivo, where Aspa-/- mice display increased PC NAA levels and glycolytic intermediates following stimulation. The role of NAA is not only metabolic, as macrophages exposed to NAA have an increased pro-inflammatory gene signature. Lastly, in contrast with previous literature, genetic perturbation of the NAA metabolic loop within the PC leads to reduced growth in a murine intraperitoneal tumor challenge model. Conclusion This work shows a role for the NAA metabolic loop within the PC, anchored by the TRM. NAA within the PC serves as a metabolic and pro-inflammatory modulator rather than a fuel, leading to increased cellular energetics, and an altered metabolome. Therefore, the primary role of Nat8l and Aspa in PC TRM may be to modulate NAA levels and control the inflammatory potential of the peritoneal cavity. Funding Source NIH Project Number ZIA BC 010300 Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Impact of SYK inhibition on the Ovarian Cancer Tumor Microenvironment 2250554

Abstract Introduction Ovarian Cancer (OvCa) is an aggressive malignancy with poor survival outcomes, driven in part by an immunosuppressive tumor microenvironment (TME). Tumor-associated neutrophils (TANs) and macrophages (TAMs) promote immune tolerance and resistance to immunotherapy, limiting treatment efficacy. We recently identified tumor-secreted epidermal growth factor-like 6 (EGFL6) as a promoter of an immunosuppressive phenotype and inducer of spleen tyrosine kinase (SYK) signaling in infiltrating myeloid cells. In this study, we investigate the impact of SYK inhibitor R788 on OvCa tumor progression and whether SYK inhibition could reverse Egfl6-dependent immunosuppressive state in myeloid cells. Methods OvCa patient tumors were assessed to determine the correlation between EGFL6 and SYK expression in myeloid cells. A syngeneic mouse model of Egfl6 +/- OvCa cells was used to elucidate the effect of SYK inhibition on tumor progression and the immune TME. In addition, the effect of R788 on anti-tumor immunity alone or in combination with Paclitaxel was also determined. Results R788 (fostamatinib) reduced the proliferation of OvCa cells, as well as myeloid cells, in a dose-dependent manner. In vivo experiments showed that administration of R788 significantly improved the survival rate and reduced ascites volume in both control and Egfl6-overexpressing tumors, and combination of R788 along with Paclitaxel provided a synergistic effect in Egfl6+ tumors. We found that R788 decreased the number of TANs and reduced VEGF, M-CSF, and CXCL5 levels in ascites. Moreover, single-cell RNA-sequencing revealed that R788 drastically reprogrammed the immune TME, with SYK inhibition associated with a) depletion of specific CCL8+ TAMs and CXCL2+ TANs; and b) reduced number of exhausted TIGIT+CTL4+ CD8 T cells. Conclusion Our findings establish the role of an EGFL6-SYK regulatory axis in OvCa progression and identify SYK inhibitor R788 as a promising therapeutic agent to induce an anti-tumor immune response in OvCa patients. Funding Source NIH-National Cancer Institute Grant R01CA276279 (awarded to S.C.) Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Divergent Immune Trajectories Influence Sex Bias in Aging Salivary Gland Autoimmunity 2309855

Abstract Introduction Sjögren’s disease (SjD) is a systemic chronic autoimmune disorder that disproportionately affects older women. The mechanisms driving this age- and sex- bias remain unclear. Here, using both inbred and genetically diverse mice, we tested how aging and sex interact to drive systemic autoimmunity and salivary gland immunopathology. Methods Inbred (C57BL/6, A/J) and genetically heterogeneous UM-HET3 mice were analyzed across 4—22 months of age. Serum anti-nuclear IgG was quantified by indirect immunofluorescence. Salivary gland immune infiltrates were profiled by immunohistochemistry and spectral flow cytometry. Transcriptional programs were interrogated using NanoString immune panels, bulk RNA-seq, and single-cell RNA-seq. Results Across genetic backgrounds, aging unmasked robust female-biased autoimmunity. Aged females developed high-titer anti-nuclear IgG antibodies and progressive lymphocytic sialoadenitis. Glandular infiltration followed a hierarchical pattern, dominated by T cells, followed by B cell accumulation, age-associated B cell enrichment, CD4 T follicular helper cell expansion, and germinal center formation. In contrast, age-matched males exhibited significantly lower autoantibody titers and were protected from severe sialoadenitis. While a subset of 22-month-old males reached autoantibody titers comparable to females, they rarely developed pronounced glandular pathology. Instead, male salivary glands had sparse B cell representation but prominent CD8 T cell infiltration with a terminally exhausted phenotype. Conclusion Aging is a dominant driver of spontaneous systemic and glandular autoimmunity, but sex-specific immune programs dictate divergent tissue outcomes. In males, terminal CD8 T cell exhaustion is consistent with a localized immunoregulatory niche that may constrain B cell accrual and limit progression to severe sialoadenitis despite systemic autoantibody production. Defining these inhibitory signals may reveal new strategies to suppress glandular inflammation in SjD. Funding Source Supported by NIH/NIDCR DE032911, DE034962, Presbyterian Health Foundation Topic Categories Basic Autoimmunity (BA)

Unmasking a Rare Infectious Complication of Th2 Pathway Inhibition: A Case of Iliopsoas Abscess Post-Dupilumab 2308060

Abstract Introduction Dupilumab, a non-immunosuppressive monoclonal antibody that reduces IL-4 and IL-13 signaling, has shown a favorable infection profile in clinical trials. Methods A 30-year-old male with a history of asthma and atopic eczema was transferred from an outside hospital. He initially presented with two weeks history of severe back pain radiating to the right hip and thigh. He had received two doses of dupilumab three weeks before this presentation. CT scan of the pelvis revealed right sacroiliac joint septic arthritis with a 3.2 x 1.9 cm collection between the right gluteus area and the right iliopsoas abscess. He was treated with intravenous (IV) vancomycin and ampicillin-sulbactam for 10 days. Repeat CT scan showed no significant improvement; he was transferred to our institution for interventional radiology-guided drainage of the abscess. He underwent the drainage, which yielded purulent fluid. IV vancomycin, cefepime, and metronidazole were initiated. The fluid for bacterial, acid-fast and fungal cultures was negative. Blood cultures showed no growth. Laboratory studies showed elevated inflammatory markers and a negative autoimmune workup. Due to persistent fevers, antibiotics were changed to IV daptomycin, cefepime, and metronidazole.MRI of the right thigh on day 8 revealed a large multiloculated gluteal abscess (9 x 2.5 x 2.5 cm) and minimal iliopsoas involvement. Due to the deep location and loculated lesion, the drainage was not feasible, and he was treated with 10 weeks of IV antibiotics. Repeat MRI showed complete resolution of abscesses and normalization of inflammatory markers, and the patient improved clinically. Results Dupilumab has non-immunosuppressive effects in trials; however, its inhibition of IL-4 and IL-13 may gradually modify host responses to bacterial infections by affecting Th2/Th1 balance, macrophage activation, or skin and mucosal barrier function. Conclusion As dupilumab’s use expands, clinicians should remain vigilant for its rare but serious infectious complications. Funding Source n/a Topic Categories Translational and Interventional Immunology (TI)

Dynamic Self‐Focusing Photothermal Localization Induced Mild Solvent‐Free Upcycling of Polystyrene

ABSTRACT The pervasive accumulation of nondegradable plastic waste, particularly microplastics, represents a critical environmental crisis demanding advanced recycling strategies. Here, we introduce a fully green, photo‐driven process for polystyrene (PS) upcycling, enabled by a synergistic thermal‐focusing and space‐confined catalysis. Using earth‐abundant MoO 3‐x , it can efficiently absorb sunlight to generate localized heat, dynamically melting adjacent PS and spontaneously forming a core‐shell MoO 3‐x @PS structure. Critically, the intrinsically low thermal conductivity of PS creates a self‐forming insulating layer, which traps thermal energy at the catalyst‐polymer interface. This self‐focusing thermal localization effect sustains a microscopic high‐temperature reaction zone under ambient conditions, dramatically enhancing energy efficiency. The concentrated heat cleaves inert C─C bonds, while photogenerated charge carriers facilitate selective oxidative degradation. Consequently, we achieve 75.0% PS conversion with 70.5% combined yield of valuable products, predominantly benzoic acid crystals that spontaneously separate post‐reaction. Operating without solvents or external heating, our strategy transforms waste PS into valuable chemicals using only sunlight. This work establishes a new paradigm for solid‐state photothermal upcycling, leveraging interfacial thermal localization to enable a truly sustainable light‐to‐chemicals circular path.

Environmental serious games foster pro-environmental intentions through spillover moderated by connectedness to nature and awe

Apotracker™ Peptides Facilitate Calcium-Independent Phosphatidylserine Targeting for Extracellular Vesicle Isolation and Analysis 2267168

Abstract Introduction Extracellular vesicles (EVs) are membrane-bound nanostructures secreted by diverse cell types, mediating intercellular signaling, immunomodulation, and pathological processes. A defining molecular feature of EVs is the externalization of phosphatidylserine (PS) on their lipid bilayer surface. Apotracker™ is a proprietary suite of synthetic peptides engineered by BioLegend (Revvity Inc.) to selectively bind PS in a calcium-independent manner, overcoming limitations of conventional annexin-based probes. These reagents have demonstrated robust performance in the detection and quantification of apoptotic and necrotic cells via flow cytometry, fluorescence microscopy, and have been integrated into MojoSort workflows for dead cell depletion. In this study, we extend the utility of Apotracker™ peptides to the enrichment and detection of PS-positive EVs derived from cultured human and murine primary cells, as well as hematological and solid tumor cell lines. Using optimized binding protocols, Apotracker™ enables efficient capture and downstream analysis of EV populations, facilitating high-resolution characterization of vesicle heterogeneity and biomarker expression. Our findings establish Apotracker™ as a versatile tool for PS positive EV research, supporting both preparative isolation and analytical detection in translational and basic science applications. Methods Using Phosphatidylserine (PS) binding reagent to enrich PS-positive Apoptotic body in calcium independent manner Results Phosphatidylserine (PS) binding reagent can detect and enrich PS-positive apoptotic bodies. Conclusion Our findings establish Apotracker™ as a versatile tool for PS positive EV research, supporting both preparative isolation and analytical detection in translational and basic science applications Funding Source n/a Topic Categories Technological Innovations in Immunology (TECH)

EQ504: A Novel AhR Modulator That Promotes Immune Tolerance Through Il-10 and Il-22 Cytokine Release 2309955

Abstract Introduction The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that promotes immune tolerance in part by enhancing regulatory T cell (Treg) development and function of macrophages. Despite its therapeutic potential inflammatory bowel disease (IBD), clinical development of AhR modulators has been limited by the lack of potent, selective and drug-like molecules. Methods We evaluated EQ504, a novel small-molecule AhR modulator derived from the endogenous ligand ITE and obefazimod, a clinically validated molecule in IBD. Human immune cells were treated with each compound to assess AhR activation, regulatory T cell differentiation, and macrophage polarization. Cytokine production and phenotypic markers were analyzed to define immunoregulatory outcomes. Results EQ504 activated AhR in both Tregs and monocytes/macrophages. The two molecules drove distinct regulatory T cell programs: EQ504 preferentially induced FOXP3⁻ Type 1 regulatory T cells (Tr1s), whereas obefazimod promoted FOXP3+ Treg differentiation. Tr1 cells are particularly relevant in IBD due to their IL-10—mediated immunosuppression, granzyme B—dependent targeting of inflammatory antigen-presenting cells, and capacity to restrain Th1/Th17-driven inflammation while supporting mucosal repair. EQ504 also shifted macrophage polarization toward an anti-inflammatory phenotype, decreasing M1 frequencies while increasing M2 frequencies, accompanied by reduced production of pro-inflammatory cytokines including IL-12p70, TNFα, IL-6, and IL-1β. Conclusion These findings identify EQ504 as a potent next generation AhR modulator with a unique immunoregulatory profile. EQ504 promotes Tr1mediated immune tolerance and anti-inflammatory macrophage polarization, mechanisms highly relevant to the treatment of IBD. Funding Source N/A Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)

From CRISPR Perturbation Screens Towards Consilient Model-Informed Principles for CAR T-Cell Design 2309679

Abstract Introduction Adoptive cell therapies must combine indefinite self-renewal with mature effector functions. Physiologically, cells are rarely simultaneously endowed with these attributes, therefore cellular therapies must, in response to environmental signals, dynamically transition between self-renewing and mature effector states while avoiding dysfunctional states. Modifying regulation via edits of TF and epigenetic modifiers can help but are pleiotropic, while exhaustive experimental discovery of cis regulatory edits (cCREs) is infeasible. Methods We introduce Consilience, a Bayesian deep generative model trained on paired scRNA-seq/scATAC-seq from human T cells. It encodes cell-state dynamics as an SDE in a low-dimensional latent space, predicts time-evolving transcriptome/regulome trajectories, and simulates perturbations to trans factors and specific cCREs with calibrated uncertainty. We also performed pooled CRISPRa screens in anti-CD20 CAR-T cells under exhaustion-provoking conditions. Results CRISPRa hits implicated TGFβ and TNFα modules in durability and nominated MFNG, NFIB, SMYD2, and TRIAP1 in central-memory—biased states - targets where full knockout may harm proliferation/cytotoxicity. Consilience supports (i) reverse screening via cis-tuning at TF loci: editing TCF7 and TOX promoters/enhancers is predicted to increase central/stem-like memory at baseline yet preserve subset-specific effector recruitment upon antigen; and (ii) forward screening via stage-resolved cCRE scans: silencing late-phase elements is predicted to block terminal exhaustion while retaining early protective programs (survival and restraint). The model proposes minimal multi-edit sets optimizing persistence, effector competence, and safety with credible intervals. Conclusion Consilience reframes CAR-T engineering as dynamical systems optimization and prioritizes tractable, minimal cis edits with predicted effect sizes. Refined training on single-cell multiomics data from CAR-T cells will further tailor designs as data mature. Funding Source Funding by the National Heart, Lung and Blood Institute Division of Intramural Research. Topic Categories Computational and Systems Immunology (COMP)

Kupffer cell identity, phenotype, and function rely on continual hepatic sympathetic nerve output 2309346

Abstract Introduction Every organ in the body is innervated and contains populations of tissue-resident macrophages. Studies show communications between peripheral nerves and immunity in various organs; however, this is seldom explored in the liver. The liver is a firewall against bloodstream infection — a function made possible by Kupffer cells (KCs), the liver resident macrophage. Being uniquely situated in liver capillaries, KCs clear up to 95% of bacteria in the blood. Despite the liver being innervated, connections between hepatic nerves and KC are unclear. Here, we explore the interplay between hepatic nerves and KCs, hypothesizing that hepatic innervation is critical for KC identity, phenotype, and function. Methods We used tissue clearing to visualize the nerves in the liver. Intravital microscopy for assessing bacteria catching by KCs. Results We show that hepatic nerve fibers are primarily sympathetic nerves which line the portal vein of the liver but terminate before reaching the capillaries where KCs reside. This suggests that there is no direct physical interaction between KCs and hepatic sympathetic nerves. Despite this, sympathetic denervation reduced expression of genes associated with KC identity and led to reduced levels of receptors critical for KC function, like CRIg — a receptor required for catching bacteria. Sympathetic denervation significantly decreased bacteria catching by KCs, resulting in increased bacterial burden in the circulation and worse survival following bloodstream infection. Mechanistically, we show that liver-specific nerves release neurotransmitters and activate β-adrenergic receptors to maintain KC function and phenotype. Specific ablation of the β2-adrenergic receptor on KCs reduced bacteria catching suggesting that KCs directly sense neurotransmitters. Lastly, reintroducing norepinephrine into denervated mice rescued bacteria catching by KCs. Conclusion Overall, this study suggests that KC identity and function depend on norepinephrine released by hepatic sympathetic nerves. Funding Source Cancer Research Institute CRI4653 Topic Categories Neuroimmunology (NEUR)

The Olfr519/OR10A3 signaling Amplifies Macrophage Inflammasome Activation and Drives Atherosclerosis 2260066

Abstract Introduction Olfactory receptors (ORs), the largest family of G protein—coupled receptors, are emerging regulators of innate immunity. While specific ORs, such as Olfr2, have been linked to vascular inflammation, the broader role of OR signaling in macrophage-driven atherogenesis remains unclear. Methods Aortic macrophages from atherosclerosis-prone Apoe-/- mice were profiled by bulk RNA-seq to identify expressed ORs. Olfr519, the receptor for 3-phenylpropylpropionate (3-PPP), a potential gut microbiota—derived metabolite, was identified and confirmed by flow cytometry in aortic and bone marrow—derived macrophages. The human ortholog OR10A3 was analyzed in plaque macrophages, monocyte-derived macrophages, and circulating monocytes following stimulation with LPS and 3-PPP. Spatial transcriptomics (COSMX SMI) examined OR10A3 expression relative to markers of inflammatory macrophages. Functional assays assessed calcium flux and cytokine secretion after 3-PPP exposure, and receptor dependence was tested by siRNA knockdown and genetic deletion. In vivo studies included administration of 3-PPP in Apoe-/- mice and bone marrow transplantation in Ldlr-/- recipients. Results Olfr519 was significantly upregulated in aortic macrophages. 3-PPP stimulation induced rapid Ca²+ flux and strong IL-1β/IL-1α secretion, which were abolished by receptor knockdown or deletion. OR10A3 was expressed in human plaque macrophages and monocytes, upregulated by LPS and 3-PPP, and co-localized with IL1B and IL1A transcripts. OR10A3 silencing reduced 3-PPP—induced IL-1β release. In vivo, 3-PPP accelerated atherosclerosis in Apoe-/- mice, whereas Olfr519-deficient bone marrow reduced lesions in Ldlr-/- mice. Conclusion The here-identified macrophage-intrinsic Olfr519/OR10A3/3-PPP axis amplifies inflammasome-dependent cytokine release and promotes atherogenesis, defining a novel GPCR-mediated sensory pathway and a potential therapeutic target for vascular inflammation. Funding Source AHA CDA Award Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)

A single-cell transcriptomic chemokine response atlas of immune cells 2309949

Abstract Introduction Chemokines are classically recognized for directing immune cell migration, yet accumulating evidence suggests that they also exert broader immunomodulatory effects that remain insufficiently characterized in vivo. Methods To address this gap, we generated a single-cell RNA-sequencing-based chemokine response dictionary by profiling immune cells from mouse lymph nodes following in vivo stimulation with 40 individual chemokines. To evaluate clinical relevance, public patient response datasets and spatial transcriptomic datasets were integrated with our datasets to access association between chemokine activity and disease states. Results Beyond confirming canonical chemotactic effects, chemokine stimulation induced distinct functional programs across immune cell types. For example, CCL8 could induce antigen-presentation-associated programs in B cells. A cell-type-centric perspective uncovered previously unidentified CXCL10-driven chemokine-driven polarization states in migratory dendritic cells that correlated positively with patient response. Integrating chemokine datasets with glioblastoma and normal brain spatial transcriptomics revealed disease-associated chemokine functions, advancing our understanding of chemokine spatial dynamics. Furthermore, incorporating chemokine datasets into our Immune Response Enrichment Analysis (IREA) software enables simultaneous prediction of cytokine and chemokine activities on immune cells based on gene expression data. Conclusion This chemokine response dictionary provides a systematic resource for dissecting chemokine-driven immune functions beyond chemotaxis. By linking chemokine activity to cellular states, spatial context and patient outcomes, this framework offers new opportunities for immunotherapeutic target discovery and response prediction. Funding Source CRI Technology Impact Award (PI: Ang Cui) Topic Categories Cytokines and Chemokines and their Receptors (CCR)

Exploring Ly49+ CD8+ T cell ontogeny and their connection to Intraepithelial Lymphocytes 2309007

Abstract Introduction KIR+CD8+ T cells are present in diverse tissues and disease states, including autoimmunity, infection, and cancer. Interest in these cells has recently increased due to their detection by single-cell transcriptomics in these contexts. However, their development and function remain poorly understood. They show gene expression and T cell receptor (TCR) features associated with autoreactivity and agonist selection, a developmental pathway shared by intraepithelial lymphocytes (IELs), another unconventional T cell population thought to contribute to peripheral tolerance in the small intestine. This study investigates the ontogeny of Ly49+CD8+ T cells, the murine equivalent of human KIR+CD8+ T cells, through single cell transcriptomic analysis of IEL precursors, with the aim of identifying Klra6+ cells, a specific marker for Ly49+CD8+ T cells. Methods Mature IEL precursors were isolated from wild-type C57BL/6 mouse thymi using a defined antibody panel (CD1d-Tet- CD25- CD4- CD8- CD5+ TCRβ+ H-2kb+ CD122+). Hashtag antibodies identified the mouse of origin and CITE-seq antibodies distinguished type-A (PD1+ NK1.1- CD44- CXCR3-) from type-B (PD1- NK1.1+ CD44+ CXCR3+) precursors. Single-cell gene expression, CITE-seq, and TCR library data were generated with the 10x Genomics platform and analyzed using Seurat in R. Results IEL precursors separated into two major groups, forming 10 clusters. Previous findings have shown that IEL precursors can be separated into two groups named type A and type B. To determine if this distinction drove clustering, module scores based on PD1, NK1.1, CD44, and CXCR3 expression were used to assign clusters as A-like or B-like. This analysis confirmed that A/B identity explained the major separation. Conclusion Klra6+ cells were distributed across both A-like and B-like clusters, rather than clustering together, suggesting the existence of two distinct Ly49+CD8+ T cell populations: one potentially functioning within the thymus and another contributing to peripheral tolerance. Funding Source St. Jude Graduate School of Biomedical Sciences Topic Categories Hematopoiesis and Immune System Development (HEM)

Wavelength‐Division Holographic Multiplexing via Cascaded Metasurfaces and THz‐Spaced Microresonator Frequency Combs

ABSTRACT Achieving high‐density wavelength multiplexing is essential for expanding the capacity of optical information processing. However, traditional optical components lack sufficient dispersion control, hindering high‐efficiency, low‐crosstalk wavefront manipulation across densely spaced channels. Here, we overcome this bottleneck by introducing a double‐layer cascaded metasurface architecture engineered via an end‐to‐end differentiable design framework. Through joint optimization, this cascaded design yields a 25‐fold increase in multiplexing density over single‐layer approaches, theoretically enabling 64‐channel holographic multiplexing with a tight 4.3‐nm spacing in the visible spectrum. Furthermore, we experimentally validate this architecture in the infrared band by utilizing a terahertz‐spaced microresonator frequency comb as a multi‐wavelength coherent source. This first‐of‐its‐kind integration of differentiable cascaded metasurfaces with on‐chip microresonator frequency combs provides a compact, highly efficient pathway for next‐generation wavelength‐division multiplexing, high‐capacity data communications, and integrated photonic systems.