Browse Articles

Neutrophil Elastase Regulates both Innate and Adaptive Immunity in SARS-CoV-2-Infected Mice 2260457

Abstract Introduction Neutrophil elastase (NE), encoded by ELANE, is a serine protease that contributes to both antimicrobial defense and inflammatory tissue injury. Our group has shown that pharmacologic inhibition of NE modulates immune responses and enhances vaccine efficacy. To define the role played by ELANE in antiviral immunity and disease severity, we examined the outcome of SARS-CoV-2 infection in wild-type (WT) C57BL/6J mice, ELANE knockout (ELANE) mice, and mice nasally treated with pharmacological inhibitors of NE. Methods Male and female mice were intranasally infected with the mouse-adapted SARS-CoV-2 MA10 and body weight and temperature were monitored to assess the severity of disease. Early host response to infection was determined by flow cytometry analysis of peripheral blood leukocyte subsets, viral load in lung tissues, and the profile of host mRNA responses. We also quantified anti-SARS-CoV-2 antibody responses in the bloodstream and mucosal tissues to determine the potential level of protection achieved against future infection. Results Both WT and ELANE mice exhibited transient hypothermia following infection with the mouse-adapted SARS-CoV-2 MA10. However, unlike WT mice, those lacking ELANE were protected from weight loss post-infection. Male and female ELANE mice displayed distinct immune signatures in the blood, with males presenting early in non-classical monocytes, as well as enhanced frequencies of B and T cells compared to WT controls. ELANE mice showed higher spike-specific IgG1 and IgG2c antibodies compared to WT controls. Additionally, in vitro, pharmacological NE inhibition with Alvelestat reduced viral plaque formation in a dose-dependent manner. Conclusion These findings identify NE as a critical regulator of host immunity and viral replication during SARS-CoV-2 infection. Ongoing single-cell RNA sequencing of infected lungs will further define NE-dependent programs governing the protective versus pathogenic immunity seen. Funding Source Role of CASP-11 in SARS-CoV-2-induced lung pathologies and long-term immune protection Parent Project Number 5P01AI175399-02 Sub-Project ID 8361 Contact PI/Project Leader BOYAKA, PROSPER N Topic Categories Viral Immunology (VIR)

Integrative Multi-Omics Profiling Identifies Candidate Biomarkers in Triple-Negative Breast Cancer 2258118

Abstract Introduction Triple-negative breast cancer (TNBC) remains one of the most therapeutically resistant breast cancers and often displays pronounced immune heterogeneity. This study integrates multi-omics datasets to identify candidate biomarkers that may influence TNBC progression and modulate therapeutic response. Methods Transcriptomic, DNA methylation, microRNA (miRNA), and single nucleotide polymorphism (SNP) datasets from public repositories were analyzed using differential expression and correlation pipelines. Expression, mutation, and regulatory metrics were then integrated to prioritize key genes. Top candidates, including CCND2 and KIF1A, were preliminarily validated using qPCR and Kaplan—Meier plots. CIBERSORT was applied to examine tumor immune cell infiltration and to assess the immune-related expression of candidate genes. Results Multi-omics integration highlighted CCND2 and KIF1A as highly ranked candidates associated with TNBC proliferation and cell cycle regulation. Literature and pathway analysis suggested potential involvement of these genes in key oncogenic and immune-related signaling pathways. Preliminary qPCR results supported their differential expression relative to normal breast tissue. Conclusion These findings nominate CCND2 and KIF1A as candidate biomarkers and potential therapeutic targets in TNBC. Continued pathway and functional validation will clarify how these genes contribute to tumor progression and may inform precision treatment strategies for TNBC. Funding Source n/a Topic Categories Translational and Interventional Immunology (TI)

Deeper Insights Into the Spin Dynamics, Enhancing Transport Performance, and Emerged Multifunctional Devices: Recent Progress in Organic Spintronics and Materials

ABSTRACT Organic spintronics is a rapidly evolving frontier interdisciplinary field because of the significant practical potential in the field of the modern electronics industry. Organic semiconductors (OSCs), which typically exhibit remarkably spin transport performance compared to inorganic counterparts owing to their light elements composing framework, have emerged as a promising platform for the development of multifunctional organic electronic devices. In recent years, as the theoretical framework of organic spin relaxation mechanisms has been further refined, many novel design strategies have been proposed, substantially enhancing the applicability of OSCs in multifunctional spintronics devices. Herein, spin transport dynamics, chemical modulation strategies, and the derivative functional devices are comprehensively summarized in this review. First, the physical pictures of the spin or carrier transport in various OSCs, especially the coupling between spin relaxations and charge or lattice dynamics, are discussed. Subsequently, the design strategies of OSCs aimed at realizing high spin transport performance are classified. Moreover, the progress in the field of several spin‐related multifunctional devices, such as spin memristor, spin light emitting diode (spin‐LED), spin photovoltaic devices, are presented. Finally, a summary and future outlook are proposed, emphasizing the diversity and potential for long‐term development in organic spintronics.

Synergistic Static and Dynamic Interfacial Regulation Toward Robust Zinc Batteries

ABSTRACT Aqueous zinc (Zn) metal batteries (AZMBs) are promising for sustainable energy storage, yet their development is severely compromised by the interfacial instability arising from a water‐rich and disordered electric double layer (EDL). Herein, we establish a rational screening strategy that combines density functional theory with molecular dynamics simulations to identify cationic regulators (both organic and inorganic) capable of reshaping the EDL structure through optimized interfacial affinity and transport kinetics. The results reveal that 1‐ethyl‐3‐methylimidazolium exhibits strong interfacial affinity, which enables the formation of a hydrophobic shielding layer that suppresses parasitic reactions, demonstrating a “static passivation” effect. In contrast, sodium ion, as electric field‐responsive species, provides “dynamic regulation” by homogenizing Zn 2+ flux and lowering the desolvation energy barrier. Consequently, this dual‐cation strategy constructs a water‐poor and ordered EDL, enabling Zn anodes to operate stably for over 5000 h with a high Coulombic efficiency of 99.73%. Ultimately, guided by these mechanistic insights, a machine learning framework is further developed to enable predictive and scalable additive screening.

The role of sleep in the association between social network addiction and depressive symptoms in university students: a cross-sectional study

Abstract This cross-sectional study examined the role of sleep quality and its individual components in the association between social network addiction and depressive symptoms among 746 university students (20.81 ± 3.99 years; 68.9% female). Validated questionnaires were used to assess social network addiction (Social Networks Addiction-6 brief version), depressive symptoms (Beck Depression Inventory-II), and sleep quality (Pittsburgh Sleep Quality Index). Sociodemographic, body composition, and lifestyle data were assessed as covariates. Statistical analysis included multivariate linear regression, logistic regression and structural equation models adjusted for major confounders. The results showed that sleep quality accounted for 23.9% of the total association between social network addiction and depressive symptoms (indirect association = 0.104, 95% CI: 0.027–0.184, p- value < 0.05). Among sleep quality components, daytime dysfunction due to inadequate sleep accounted for 31.2%, whereas sleep latency and use of sleep medication accounted for 10.1% and 11.3%, respectively ( p -value < 0.05 for all). Future prospective studies should examine whether interventions targeting sleep quality may represent a potential strategy for reducing depressive symptoms associated with SNA in this population.

Dysregulated host responses are associated with severe influenza A virus disease in individuals with arterial hypertension 2335206

Abstract Introduction Influenza A virus (IV) infections cause seasonal epidemics, which remain a major cause of morbidity and mortality worldwide. Disease severity depends on virological and host factors including age, immune status and comorbidities. The molecular signatures regulating host response dynamics that influence disease progression are poorly understood. Methods We analyzed and integrated cytokine and multi-Omic data (transcriptomic, cell deconvolution, metabolomic and lipidomic) from severe (n = 135) and mild (n = 126) influenza patients. Using MOFA (a factor analysis model) and Lasso regression, three factors (1, 4, and 6) were selected in a model predicting disease severity, adjusted for hypertension, a significant more prevalent condition among severe individuals, when considering the acute and post-infection time points. Results Two of the selected factors were strongly associated with hypertension. Enrichment scores for top cell type subsets showed significantly higher values for CD8+ T-cells, CD8+ Tcm (factor 1) in mild vs severe individuals at the acute phase and B-cells (factor 7) post-infection. Pathway enrichment on factors with transcriptomic signatures (factor 1 and 6) showed neutrophil degranulation and complement/coagulation cascades with a higher score in severe vs mild patients at early timepoints, meanwhile TCR signaling/T cell activation and IFN signaling were significantly lower in severe vs. mild individuals. Interestingly, antibody responses assessed against the globular head and stalk regions of the hemagglutinin glycoprotein showed that, regardless of disease severity, most individuals developed robust humoral responses against either H1 or H3 IV infection, indicating that antibody titers alone are a limited correlate of protection. Conclusion These findings suggest that early dysregulation of innate and cellular immune responses plays a crucial role in modulating disease outcome in individuals with hypertension, providing mechanistic insights into severity in this at-risk population. Funding Source FLU-CODE 1U01AI187057-01 and FLUOMICS Consortium U19AI110819, from NIH-NIAID CRIPT, a Center for Excellence on Influenza Research and Surveillance NIH-NIAID grants HHSN272201400008C and 75N93021C00014 NIH-NIAID Systems Approach to Understand Mechanisms Topic Categories Computational and Systems Immunology (COMP)

Diabetogenic CD8 Tcells are highly adaptive in beta-cell antigen recognition 2258433

Abstract Introduction Type 1 diabetes (T1D) is an autoimmune disease in which cytotoxic CD8+ T cells destroy insulin-producing β cells through TCR recognition of β-cell antigens presented by MHC class I. Yet, how CD8 T cells recognize these self-antigens and bypass self-tolerance remains unclear. We used ultrasensitive two-dimensional (2D) assays to quantify TCR affinity and bond lifetime, aiming to reveal how antigen recognition dynamics drive diabetogenic CD8 T cell activation. Methods We focused on two diabetogenic TCR transgenic systems–G9C8 and NY8.3–which recognize distinct β-cell autoantigens, an insulin epitope and an IGRP epitope, respectively. Using 2D kinetic measurements, we assessed TCR affinity and bond lifetime during thymocyte selection and after diabetes onset. To test generality, we further performed single-cell RNA sequencing (scRNA-seq) combined with TCR V(D)J sequencing on T cells from IGRP/insulin peptide-immunized mice, selected a panel of TCRs specific to each peptide, generated corresponding TCR retrogenic mice, and repeated the same 2D measurements. Results Our data show that CD8 T cells form weak bonds with β-cell antigens during thymocyte selection but greatly increase bond strength after activation upon diabetes onset. This adaptive self-reactivity occurs at the single TCR clonal level and is mediated by the CD8 coreceptor rather than by changes in the TCR itself. Notably, this phenomenon was not observed for foreign antigen recognition. The follow-up experiments with newly generated TCRs of the same specificities confirmed the highly adaptive self-reactivity of diabetogenic CD8 T cells. Conclusion These findings support a model in which, during autoimmune diabetes, CD8 T cells fundamentally alter self-antigen recognition by modulating TCR binding kinetics. This enables them to evade thymic negative selection while acquiring heightened self-reactivity in the periphery, ultimately mediating β-cell destruction and disease onset. Funding Source RO1 Topic Categories Basic Autoimmunity (BA)

Dietary exposure modulates cutaneous immunity and microbiota to facilitate wound healing 2308096

Abstract Introduction Nutrition influences all host physiological processes, yet its role in regulating tissue repair remains poorly understood. Although both the immune system and the microbiota have been implicated in tissue repair, how diet reshapes host physiology, microbial function, or host—microbe interactions to promote regeneration has not been investigated. Methods To test this, we manipulated the nutritional status of mice using either dietary restriction or nutrient-enriched diets and assessed wound closure following injury. Results Here, we show that the ketogenic diet (KD), a diet enriched in fats and low in carbohydrates, feeding reshapes the metabolic environment of the skin and enhances both the abundance and metabolic output of the commensal Staphylococcus epidermidis. In vivo metatranscriptomics revealed KD-induced increases in microbial glycolysis, nucleotide synthesis, and riboflavin-pathway activity. Lipidomic profiling further showed that KD elevated bacterial sphingomyelinase-dependent ceramides in the epidermis. These diet-responsive microbial metabolites amplified cutaneous γδ T cell and mucosal-associated invariant T (MAIT) cell responses and directly promoted keratinocyte activation, collectively accelerating wound repair. Genetic disruption of microbial ribD or sphingomyelinase impaired these effects, demonstrating that host nutritional status drives tissue regeneration by rewiring commensal metabolic programs. Conclusion Together, our findings reveal a diet-sensitive metabolic axis through which skin microbes coordinate tissue regeneration. Funding Source Supported by NIAID; 1ZIA-AI001115 and 1ZIA-AI001132; JSPS CPD Reseach Fellowship for Young Scientist Topic Categories Mucosal and Regional Immunology (MUC)

Evaluation of Salmonella bearing Tumor-targeting Peptides for Cancer Therapy 2334639

Abstract Introduction Salmonella, known for its facultative anaerobic nature to replicate in tumors and ability to deliver foreign genes into tumors, is a promising candidate for anticancer therapies. However, clinical trials showed that the targeting ability needs to be strengthened. This study focuses on testing the adhesion and invasion efficiency of tumor-targeting Salmonella vectors. Methods Engineered Salmonella vectors were designed to express tumor-targeting peptides along with a GFP reporter to study their interactions with cancer cells. Peptides were fused to the outer membrane protein A (OmpA). To determine optimal infection conditions, CT26 colorectal carcinoma cells were exposed to different multiplicities of infection (MOI 1, 10, and 100). After imaging with a fluorescence microscope, fluorescence analysis conducted in Fiji identified MOI 10 as the most effective condition for characterizing differences among peptides. Using this condition, CT26 cells were infected with four different Salmonella vectors carrying the wild-type ompA gene (ompAW) and genes encoding the peptides GE11, RKO, and TK. Results Colony-forming unit (CFU) data across three biological replicates revealed RKO showed potential for attachment. TK and RKO peptides are promising candidates for invasion. Although variability was observed across biological replicates, the overall trends were maintained, with RKO displaying the strongest performance and TK showing intermediate activity. Conclusion Overall, these findings identify peptides that can affect the Salmonella tumor-targeting abilities. Peptide candidates have the potential for further therapeutic development. Further replicates will be needed to validate potential peptide candidates. This research represents a novel approach to bacterial-mediated cancer therapy, offering potential breakthroughs in targeted treatment strategies. Funding Source N/A Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

The Immune Signatures Data Resource 2.0: An Expanded Compendium of Systems Vaccinology Datasets 2304506

Abstract Introduction Vaccines are among the most impactful public health interventions. Systems vaccinology leverages high-dimensional omics data to elucidate mechanisms of vaccine-induced immunity, but these data are often fragmented across studies with heterogeneous metadata, limiting cross-study analyses. The NIH/NIAID Human Immunology Project Consortium (HIPC) previously addressed this challenge by releasing the Immune Signatures Data Resource (ISDR). Here, we present ISDR 2.0, an expanded and standardized framework that harmonizes human systems vaccinology datasets using ImmPort metadata. ISDR 2.0 broadens vaccine coverage and introduces a robust, reproducible analysis pipeline for consistent data processing, quality control, and immune response interpretation. Methods We developed an automated pipeline to integrate experimental design, clinical metadata and serological response data from ImmPort with linked transcriptional profiling data from GEO. Using these standardized metadata, we constructed a MultiAssayExperiment object that unifies molecular data with subject demographics and vaccine details for seamless analysis. Results The ISDR 2.0 provides a harmonized collection of 9,638 gene expression samples from 2,544 subjects across 51 studies, covering 36 different vaccines. Through the newly developed automated harmonization pipeline, this comprehensive dataset incorporates extensive RNA-seq data, offering a computationally ready platform with enhanced statistical power for identifying pan-vaccine immune signatures. Conclusion The ISDR 2.0 provides the systems vaccinology community with a standardized dataset for analyzing human vaccine response data. By harmonizing a large number of samples, standardizing metadata via ImmPort, and processing data through a reproducible pipeline, this resource will accelerate the identification of robust immune signatures and enable the development of powerful, predictive models critical for next-generation vaccine design. Funding Source NIH grants U01AI167892 Topic Categories Vaccines and Immunotherapy (VAC)

Investigating the antibacterial and pro-coagulant activity of neutrophil-derived extracellular vesicles induced by phagocytosis of S. aureus 2254459

Abstract Introduction Extracellular vesicles (EVs) are small nanosized particles with the ability to influence host-pathogen interactions. Their function depends on several factors, including the status of the EV-releasing cell type. For example, EVs produced from neutrophils (PMN) challenged with S. aureus (PMN-SA-EVs) initiate the intrinsic pathway of coagulation, but EVs released spontaneously from neutrophils do not. The goal of our work was identifying the mechanism for the pro-coagulant activity and identify other effects PMN-SA-EVs have on the host response. Methods To test whether an EV surface protein was required for pro-coagulant activity, we treated PMN-SA-EVs with proteinase K (PK) and measured thrombin generation (TG). We also explored whether PMN-SA-EVs had antibacterial properties. Toward this goal, we investigated the effect of EVs on transcription in monocyte-derived macrophages and on the growth of bacteria. Macrophages were treated with spontaneously released PMN-EVs or PMN-SA-EVs. Results In support of protein involvement, PK treatment of PMN-SA-EVs reduced TG.There were minimal transcriptional differences between the two conditions, with transcriptional responses corresponding to donor identity instead of treatment groups. In contrast, EVs had a direct effect on bacteria with PMN-SA-EVs reducing growth of new S. aureus cultures. Conclusion This work better elucidates the role of PMN-SA-EVs in host-pathogen interactions, and our future efforts aim to uncover the mechanisms in more detail. Funding Source William and Linda Frost Fund Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

The Indigestible Burden of Microplastics Drives Bioenergetic Dysfunction in Macrophages 2260413

Abstract Introduction To date, over 7 billion tons of plastic waste has been generated, of which, 80% has accumulated in the environment. Macrophages, the first line of innate cell defense, phagocytose microplastics (MPs) but are incapable of breaking them down. Regrettably, the consequences of MP accumulation on innate immunity and human health remain unknown. Methods Monocyte-derived macrophages and Raw264.7 cells were cultured with polystyrene MPs of various sizes (.02-10µm), concentrations (1-50,000 MPs/cell), and durations and assessed for function and phenotype. Cell bioenergetics were measured by mitochondrial (mt) mass, mt polarization, and by Seahorse for cellular metabolism. 3x10^6 1µm or 4µm MPs were delivered intranasally to FVB mice and after 7 days, extrapulmonary dissemination measured and pulmonary macrophages (pMacs) analyzed via RNAseq. Results Macrophages readily phagocytose but fail to clear MPs which amass in Rab5a+ early phagosomes. In vitro, MPs induced IRF activation and increased ROS, TNFa, and CCL2, while inhibiting antigen presentation, T cell stimulation, and tumor phagocytosis. Tom20-stained mt were seen to wind around and coat intracellular MPs leading to decreased mt polarization, mass, and reduced OxPhos which could be partially reversed with an AMP kinase activator (AICAR). In vitro, MPs but not diesel exhaust particulate inhibit expression of the mtDNA genes ND3, TRNP, and ATP8 reducing ATP production. In vivo, MPs induce unique transcriptional profiles in pMacs, including chemokine upregulation (CXCL1 and CXCL3) and inhibition of autophagy (Ulk4), that were distinct from exposure to diesel exhaust and pesticides. Conclusion These findings suggest that progressive accumulation of MPs inhibits cellular bioenergetics resulting in macrophage dysfunction. Over time, reduced macrophage functions, such as efferocytosis, may result in chronic, smoldering inflammation underlying the pathobiology of chronic lung disease and lung cancer. Funding Source Department of Defense CDMRP, Department of Cardiothoracic Surgery University of Pittsburgh School of Medicine Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Activity in vivo of in vitro expanded and adoptively transferred antigen-specific CD8+ T cells against neoepitopes that mediate tumor rejection 2306826

Abstract Introduction A subset of somatic passenger mutations in cancer cells lead to generation of peptides which can be presented by MHC I molecules and recognized by CD8 T cells. Such peptides are tumor- specific and are termed neoepitopes. A small subset of neoepitopes can immunize mice against tumors in models of prophylaxis and some of them can be used to treat preexisting mouse tumors in models of therapy (see Srivastava J Clinical Investigation 2025 for review). Methods We identified and selected antigen-specific CD8+ T cells using pMHC class I tetramers. A novel expansion method was applied to generate antigen-specific CD8+ T cells in vitro. Expanded antigen-specific T cells were adoptively transferred to tumor-bearing mice, and their antigen-specific clonal response, functional properties, and cell-fate decisions were assessed by flow cytometry following transfer. In addition, enriched whole tumor-infiltrating lymphocytes were examined with single-cell RNA-sequencing to characterize transcriptomic profiles. Results Here, we have analyzed antigen-specific CD8+ T cells against neoepitopes PDPRMUT, C3MUT and Ccdc65cMUT, all of which mediate tumor rejection of BALB/c Meth A fibrosarcoma (Ebrahimi-Nik et al. JCI Insight 2019, Nature Communications 2021, Singhaviranon et al. Nature Immunology 2025). We have developed methods of expansion in vitro of CD8+ T cells against these neoepitopes and have characterized their phenotypes in vitro, and after adoptive transfer into 10-day old Meth A bearing mice by multi-panel flow cytometry and RNASeq. Conclusion These studies shed new light on the mechanisms by which neoepitope-specific CD8 T cells migrate to the tumor bed, proliferate, kill tumor cells, get exhausted and die. They also highlight the factors that limit the activity of neoepitope-specific CD8+ T cells in vivo and how these limitations can be addressed to obtain a better mechanistic understanding of neoepitope function. These mechanistic insights can also be used for a better immunotherapy of cancers. Funding Source UCONN HEALTH Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Play‐Doh Inspired a Transformative, Shape‐Adaptive iHEÄLS Enabling Post‐Crosslinking Mechanical‐Biological Modulation and Its Effectiveness in Musculoskeletal Repair

ABSTRACT Resorbable biomaterials are being developed as alternatives to traditional medical fillers for musculoskeletal repair. However, current materials fail to provide stable wound sealing and tissue regeneration due to inadequate conformal adaptability to irregular defects, weak adhesion in wet environments, and insufficient mechanical robustness balanced with biodegradability. Here, we present iHEÄLS, a transformative, shape‐adaptive biomaterial inspired by Play‐Doh, composed of cellulose nanocrystal (CNC)‐based triple‐networks. The interactions among the triple‐networks enable conformal defect filling, robust tissue adhesion, and shape stabilization through self‐healing. Mechanical training after crosslinking reinforces the network through aligned polymer chains and uniformly oriented CNC. As a biodegradable extracellular matrix, iHEÄLS promotes cell migration and osteogenic differentiation by leveraging nanomaterial incorporation and post‐crosslinking mechanical training to amplify bioactivity and mechanotransduction signaling. Additionally, iHEÄLS demonstrates enhanced hemostasis by quickly absorbing biofluids while maintaining malleability, facilitating effective mixing with autologous bone fragments, and promoting bone regeneration in a critical‐sized calvarial defect model. Overall, iHEÄLS integrates post‐crosslinking mechanical‐biological modulability with user‐friendly handling, providing a practical platform for musculoskeletal repair in emergencies.

Mapping the thymus in the viscoelastic landscape of biological tissues

A Tonsil Organoid Model for Epstein-Barr Virus-Host Immune Interactions in Germinal Centers 2308488

Abstract Introduction Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that establishes lifelong persistence in B lymphocytes by adopting distinct latency programs within lymphoid tissues such as the tonsils. In vitro, EBV infection of primary B cells drives transformation into latency III lymphoblastoid cell lines (LCLs) with tumor-like phenotypes. In contrast, in vivo EBV-infected cells are predominantly found in germinal center (GC) and memory B cell compartments, exhibiting restricted latency states (IIa, I) with limited viral antigen expression. The developmental origin of these in vivo infected populations remains unknown, as existing models fail to recapitulate the tonsillar immune microenvironment necessary to study EBV-driven B cell differentiation pathways beyond LCL transformation. Methods We developed a tonsil organoid system preserving native immune cell composition and supporting GC formation. Organoids were infected with EBV and analyzed by flow cytometry and scRNAseq. Immune cell depletion experiments dissected cellular interactions driving EBV-induced B cell responses. Results We discovered that EBV directly drives naïve B cell differentiation into CD10+BCL6+ GC-like cells, a pathway distinct from canonical LCL transformation. A subset acquired latency IIa programming (LMP1+EBNA2-), recapitulating in vivo EBV+ GC cell phenotypes. This differentiation depends on germinal center immune microenvironment, and complete immune cell depletion abrogated GC-like B cell formation. Tfh cell depletion partially blocked differentiation, which was rescued by IL-21 supplementation, demonstrating Tfh-derived IL-21 as a critical driver. Conversely, CD8+ T cells from EBV-seropositive donors suppressed this differentiation, revealing adaptive immune control. Conclusion Our findings reveal how tonsillar immune cells orchestrate EBV-infected B cell fate and viral latency programming, providing a platform for developing immune-based therapies for EBV-associated lymphoproliferative diseases. Funding Source National Institutes of Health grant R01 CA228700 (BEG), American Cancer Society Discovery Boost Grants (BEG), American Cancer Society Postdoctoral Fellowship PF-23-1144614-01-IBCD (YS) Topic Categories Viral Immunology (VIR)

A novel mice colitis model recapitulates human T cell and myeloid cell reconstitution to Support drug evaluation of inflammatory bowel disease 2258809

Abstract Introduction Inflammatory bowel disease (IBD) is a chronic autoimmune disorder of the gastrointestinal tract with complex pathogenesis. Conventional IBD animal models primarily rely on the activation of the murine immune system, which limits their translational relevance and the in vivo evaluation of human-specific biologics. To address this gap, we developed a novel humanized colitis mouse model that combines a reconstituted human immune system with dextran sulfate sodium (DSS), better reflecting human IBD pathology. Methods Severe immunodeficient mice NCG-M/hIL15 were engrafted with human hematopoietic stem cells (huHSC), and allowed to reconstitute human immune cells for 12 weeks. Colitis was induced using 3% (DSS) administered for 10 days. The therapeutic efficacy of adalimumab was evaluated at the onset of DSS exposure. Results huHSC-NCG-M/hIL15 mice demonstrated robust human T and myeloid cell subpopulations 12 weeks after engraftment of HSCs. Following DSS challenge, humanized mice exhibited significant changes in body weight, colon length, and mouse survival, along with disrupted colonic epithelial integrity, compared with untreated controls. Treatment with adalimumab ameliorated disease activity index (DAI), mortality, and histopathological scores, while reducing human TNF mRNA expression relative to the DSS control group. Conclusion The DSS-induced huHSC-NCG-M/hIL15 mouse model successfully recapitulates key immunopathological features of human IBD, including human T and myeloid cell responses. This model provides a valuable in vivo platform for assessing the efficacy of human antibodies and novel therapies in IBD research and drug development. Funding Source n/a Topic Categories Therapeutic Approaches to Autoimmunity (THER)

Multi-omics and longitudinal immune profiling uncover a distinct monocyte phenotype distribution and function in Kawasaki disease 2308476

Abstract Introduction Kawasaki disease (KD) is an acute childhood vasculitis marked by strong monocyte (MO)-driven innate activation. Despite their central role, MO’s dynamics during acute KD and their modulation by intravenous immunoglobulin (IVIG) remain poorly defined. Here, we characterize the MO compartment in KD compared with age- and gender-matched febrile (FC) and healthy controls (HC), before and after IVIG by an integrated multi-omics approach. Methods KD were tested at diagnosis (T0), 48h (T1) and 4 weeks (T2) post-IVIG. MO phenotype and LPS-induced responses assessed by flow cytometry, along with plasma proteomics (Olink PEA), were integrated with clinical and echocardiographic data. MO transcriptomic profiling was performed by Nanopore RNA sequencing. Results Upon LPS stimulation, KD MO showed overall enhanced TNF-α (p < 0.01) and IL-6 (p < 0.05) responses compared with FC. Leiden clustering revealed phenotypical differences among MO subsets. C1, corresponding to classical (CL) MO (CCR2, CD14, CD93), was reduced in KD at T0 compared with HC (p < 0.05). In contrast, C6, sharing a CL MO backbone but displaying activated/proliferative features (Ki67 and CD38), was increased in KD (p < 0.05), indicating a functional reprogramming of the CL compartment, consistent with its expansion in KD and correlates with APBB1IP, a protein differentially expressed between KD and HC and associated with coronary artery involvement (p = 0.01). C9, displaying an immature proliferative profile (Ki67, CD38, lacking subset-defining markers), was enriched in KD T0 versus FC (p < 0.05). At T2, C1 and C9 reverted toward HC levels. Conclusion Overall, this study provides a subset-resolved phenotypic and functional characterization of MO in KD, revealing disease-specific alterations that are partially normalized by IVIG. These findings highlight a central role for MO, particularly pathways linked to activation and extravasation, in KD immunopathogenesis. Ongoing MO RNA-seq analyses will further clarify the transcriptional pathways involved. Funding Source n/a Topic Categories Immune Mechanisms of Human Disease (HUM)

Plasma IgM inversely correlates with coronary artery AS risk 2335222

Abstract Introduction B cells are important immune cells in murine atherosclerosis (AS), regulating lesion development in a subset-dependent manner. B-2b cells promote atherosclerosis while B-1b cells and marginal zone B cells (MZB) exert atheroprotective effects largely through the production of IgM antibodies. IgM is thought to limit AS through clearance of harmful oxidative byproducts in plaques and recognition of immunogenic oxidation specific epitopes. IgM has been shown to inversely associate with coronary artery AS severity. Yet, whether IgM levels are associated with early indices of AS like coronary artery calcium (CAC) and coronary computed tomography angiography (CCTA) risk score (CRS) is unknown. We investigated the relationship between total IgM levels and imaging risk scores in a human cohort. Based on previous work, we hypothesize an inverse relationship. Methods We performed enzyme-linked immunosorbent assay (ELISA) for total IgM levels on plasma samples from 318 subjects in the Coronary Assessment in Virginia (CAVA) cohort, who underwent CCTA to obtain CAC and CRS measurements. CRS which considers which severity and spatial extent of coronary plaque and CAC score, which measures calcium deposits in arteries, are predictors of cardiovascular risk. Multivariate and Univariate analysis were measured in R and further correlated in PRISM. Results Univariate analysis demonstrated that plasma IgM levels did not correlate with traditional AS risk factors such as hypertension, diabetes, hyperlipidemia, BMI, and smoking history. Plasma IgM levels did correlate inversely with the CRS (r=-0.931, p = 0.022) and CAC score (r=-0.0070, p = 0.049). The inverse relationship between CRS and IgM was retained for multivariate analysis (r=-0.878, p = 0.043). Conclusion Our data indicates that higher plasma IgM is associated with lower cardiovascular risk in early AS, suggesting it may have potential as a biomarker in human populations that could benefit from early risk factor modification. Funding Source Leducq Foundation, NIH R01 AI172112 Topic Categories Basic Autoimmunity (BA)

Epigenetic Regulation of FosB in Mast Cells 2306012

Abstract Introduction Early life adversity (ELA) leads to increased chances of developing proinflammatory disorders like allergy later in life. Mast cells are innate immune cells that regulate immune response to infection and allergens through the release of inflammatory mediators such as cytokines and histamines. ELA causes increased mast cell numbers and activity in the dura mater in adult mice. FosB is highly expressed in active mast cells and acts as a negative feedback mechanism to limit mast cell activation. This raises the question of whether ELA can epigenetically regulate the expression of the FosB gene later in life. Methods Wildtype mice undergo Neonatal Maternal Separation plus Early Weaning (NMSEW) as a model of ELA. Litters are either separated for 3 hours daily in individual cups from postnatal days 1-16, weaned early at day 17, and left in their home cages until adulthood, or normally weaned at day 25 and left in their home cages. Upon adulthood, bone marrow is differentiated into bone marrow derived mast cells (BMMCs) and then sensitized and activated by IgE-DNP (allergic activation), and FosB expression assessed by qPCR and Western Blot, and histone modifications are assessed by CUT&RUN. Results We see that NMSEW increases ΔFosB expression in BMMCs derived from adult mice. This increase is seen both basally and following allergic activation. We are now in the process of using CUT&RUN to determine the changes in FosB gene structure at various stages of development following NMSEW. Conclusion Increased FosB could represent a crucial epigenetic and transcriptional mechanism regulating mast cell activation following early life adversity, potentially inhibiting further mast cell activation and limiting the effects of ELA on inflammatory disease later in life. Funding Source NIH National Institute of Allergy and Infectious Diseases, NIH Eunice Kennedy Shriver National Institute of Child Health and Human Development Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)