Browse Articles

SOCS1 Antagonist Inhibits SARS-like Virus Mediated Cell Death 2308621

Abstract Introduction The mammalian protein suppressor of cytokine signaling 1 (SOCS1), can inhibit the activity of Janus Kinase 2 (Jak2), serving to critically limit the magnitude and duration of inflammatory processes and prevent autoimmunity. SOCS1 can be hijacked by viruses, such as SARS-CoV-2, and cancers to prevent Jak2-mediated detection and elimination. Notably, a peptide corresponding to the activation loop of JAK2, pJAK2(1001—1013), has been shown to act as a decoy for SOCS1 binding and suppresses SOCS1 activity. However, the ability of the SOCS1 antagonist, pJAK2(1001—1013), to restore cellular immune responses and enhance viability in response to SARS-CoV-2 infection remains unclear. Methods To evaluate this, we assessed viability (crystal violet), viral replication (confocal microscopy), and gene expression (qPCR) of baby hamster kidney (BHK) cells expressing the human ACE-2 receptor with a laboratory safe SARS-CoV-2 pseudo virus with and without pJAK2 treatment. Results Based on our findings, the SOCS1 antagonist peptide decreased cell death caused by SARS-CoV-2 infection. Treatment with pJAK2 also reduced viral replication compared to cells without treatment. Preliminary findings indicate that pJAK2 can significantly enhance gene expression of proinflammatory cytokines such as IL-1, IL-6, and TNFï•¡. Conclusion These results suggest that the antagonist peptide has potential as a therapeutic agent against SARS-CoV-2 infection, or cancers, by enhancing cell viability and boosting immune responses through activation of the JAK/STAT signaling pathway. Future research will investigate the effects of pJAK2 on viral entry and replication using flow cytometry. Funding Source University of Florida Topic Categories Vaccines and Immunotherapy (VAC)

C3 complement inhibition by Sicpin, a salivary protein from Simulium nigrimanum 2328025

Abstract Introduction Complement inhibition is a key strategy used by many blood-feeding arthropods to ensure successful feeding. Mosquitoes, ticks, sand flies, and other hematophagous species secrete salivary proteins that block different steps of the complement cascade. These inhibitors prevent complement-mediated lysis and inflammation at the feeding site, allowing the arthropod to feed efficiently while also creating a more permissive environment for pathogen transmission Methods Here, we characterize the anti-complement activity of Sicpin, a salivary protein from the blackfly Simulium nigrimanum. Sicpin was found to inhibit all three pathways of complement activation. Surface plasmon resonance analysis revealed a strong and specific interaction with C3, with no detectable binding to other complement components common to the pathways. Results The binding induces a conformational change in C3 that blocks the interaction with the C3 convertase, consequently inhibiting the deposition of downstream complement proteins. Additionally, in both acute lung injury and sepsis models, Sicpin enhances survival and exhibits anti-inflammatory activity. Conclusion These findings support that Sicpin modulates the complement system, with potential implications for pathogen transmission, blood feeding, and therapeutic development Funding Source NIH Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)

Human Spleen Organoids as a Preclinical Platform for Evaluating Vaccine-Induced Antibody Responses 2261165

Abstract Introduction Human spleen organoids represent a promising ex vivo model that recapitulates the cellular diversity, spatial architecture, and immune functionality of secondary lymphoid tissues. These organoids offer a human-relevant platform for preclinical vaccine evaluation, potentially improving translational insight into immunogenicity. While recent studies have demonstrated antigen-specific immune responses to live-attenuated vaccines in spleen organoids, it remains unclear whether such responses extend to subunit-based immunogens, which form the basis of many modern vaccines. To address this, we evaluated the ability of spleen organoids to generate antibody responses to protein subunit immunogens. Methods Organoids were stimulated with wild-type SARS-CoV-2 spike and receptor-binding domain (RBD) proteins multimerized on mi3 nanoparticles, both with and without adjuvant formulations. Antigen-specific B cell activation was monitored by flow cytometry and ELISA, and antibody maturation was evaluated through single B cell sorting and sequencing. Results Consistent with waning immune memory observed in post-pandemic human populations, baseline responses to wild-type immunogens were modest. However, booster formulations and adjuvanted constructs enhanced antigen-specific responses, highlighting the platform’s sensitivity to immunogen design and immune memory dynamics. Conclusion Together, these results suggest that human spleen organoids can model both the baseline and augmented humoral responses to protein subunit vaccines, underscoring their potential as a human-derived platform for preclinical vaccine testing and immune response modeling. Funding Source Gates Foundation Topic Categories Vaccines and Immunotherapy (VAC)

Low‐Temperature Melting–Crystallization Transition in Perovskites With Self‐Trapped Excitons for Photovoltaic Downconversion

ABSTRACT Self‐trapped exciton (STE) emitters demonstrate exceptional luminescent downconversion (LDC) performance, achieving near‐unity photoluminescence quantum yields (PLQY) and broadband emission that overcomes Stokes shift limitations in conventional fluorophores. While these properties originate from precisely engineered Jahn–Teller distorted centers through optimized ligand fields and quantum confinement, practical challenges in stability and solution processability have hindered photovoltaic integration. In this work, we develop tin‐halide perovskite exhibiting unique low‐temperature (125°C) reversible melting–crystallization transitions for solution processability, as well as highly efficient (>90% PLQY) broadband LDC through zero‐dimensional STE emission. When integrated as the LDC layer, this reversible melting–crystallization STE emitter enhances the external quantum efficiency of silicon solar cells in the short‐wavelength region, leading to an absolute improvement in power conversion efficiency of over 0.75%. Our findings establish a new paradigm for low‐temperature melt‐processed perovskite integration in silicon photovoltaics, offering both economic viability and scalability for performance enhancement beyond current technological limits.

Glucose-6-phosphate dehydrogenase variants modify 3D genomic organization to suppress maladaptive gene expression and vascular disease

Healthcare provider and organizational readiness of mobile-based app implementation for disease classification in northwest Ethiopia: a cross-sectional study

Oncogenic mutations drive immunity through a neuron-ILC axis 2307494

Abstract Introduction The tumor microenvironment (TME) in established cancers is well studied due to its critical role in patient response to immunotherapy. However, much less is known about how the TME and immune recognition evolve during the earliest stages of tumor initiation. We investigated how oncogenic mutations in tissue-resident stem cells shape early immune responses in the skin before visible tumor formation. Methods We used complementary molecular, cellular, and imaging approaches, including single-cell RNA sequencing, flow cytometry, and immunofluorescence, to characterize early immune responses in skin harboring oncogenic mutations in tissue-resident stem cells. These methods were used to define immune cell composition, activation states, and interactions within the evolving tissue microenvironment. Results Oncogenic mutations in epidermal stem cells triggered a strong early immune infiltration prior to the appearance of any cancerous lesion. This response consisted predominantly of locally proliferating ILC1s. ILC1s in mutated skin expressed elevated levels of Granzyme C and the activation receptor NKp46, consistent with their rapid response capacity and involvement in anti-tumor immunity. Mutated stem cells upregulated the neuropeptide PYY, whose receptor is present on skin-innervating neurons. Loss of PYY in mutated skin correlated with reduced ILC1 numbers, suggesting that neuronal signaling downstream of stem-cell-derived PYY promotes activation and expansion of dermal ILC1s. Conclusion Mutations in otherwise healthy-appearing stem cells are sufficient to reshape the tissue microenvironment. Our findings identify a stem cell—neuron—ILC1 axis that primes early immune surveillance and contributes to controlling tumor formation during the initial stages of carcinogenesis. Funding Source NYSCF Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Talin-1 determines the direction of primary mouse neutrophils migrating in vivo 2223401

Abstract Introduction Neutrophils rely on β2 integrins, mainly LFA-1 and Mac-1, to mediate rolling, arrest, spreading and transmigration at inflamed sites. β2 integrins activation requires talin-1 binding to the cytoplasmic tail, yet the timing and localization of talin-1 recruitment and its distribution in vivo remain unclear. Methods To address this, we generated EGFP-talin1 (EGFP-talin1/EGFP-talin1) knock-in mice that enable real-time visualization of endogenous talin-1. EGFP-talin1 was expressed in neutrophils and supported β2 integrin activation without altering integrin surface expression or hematopoiesis. Results Using total internal reflection fluorescence microscopy showed that talin-1 was recruited to the plasma membrane during rolling and increased after arrest. Intravital imaging revealed that redistribution of talin-1 to endothelial contacts during luminal crawling and to the leading edge during transendothelial migration. After transendothelial migration, talin-1 polarized to the front and accumulated at emerging lamellipodia during the interstitial migration and before directional turning. Conclusion These results define the spatiotemporal dynamics of talin-1 during neutrophil recruitment and highlight talin-1 polarization as a key regulator of migratory directionality in vivo. Funding Source Supported by NHLBI, NIH (P01HL151433, Ginsberg PPG). Topic Categories Cellular Adhesion, Migration, and Inflammation (CAM)

Homologous MHC Antigens Induce cDC1-like Differentiation from Monocyte-Derived Dendritic Cells 2264969

Abstract Introduction Antitumor CD8+ T cell responses are orchestrated primarily by lineage-committed cDC1 dendritic cells (DC). However, data suggest that monocyte-derived DC loaded with homologous MHC antigens–bound MHC class I and II peptide epitopes sharing identical stretches of amino acid sequence, similarly elicit strong and durable CD8+ T-cell responses. Our clinical work further demonstrates that therapeutics based on this principle substantially extend survival in glioblastoma Methods Based on these critical observations, we used human and mouse moDCs to understand the mechanism(s) through which homologous MHC epitopes are detected and how signal transduction alters moDC phenotype. Results Here, we show that MHC peptide homology is sensed by the multi-aminoacyl tRNA synthetase (mARS) complex. We have demonstrated that the composition of aaRS within the mARS complex changes in accordance with the specific amino acids present in the sequence overlap region of bound MHC class I and class II peptides. To transmit the homology signal, the mARS complex relays information through mTORC1 via Rags, small GTP-binding proteins that act as intermediaries between amino acid sensors and the mTORC1 signaling pathway. Using RNAseq, RPPA, microscopy and western blot, we demonstrated a reduction in mTOR activation and phosphorylation of downstream targets p70S6K and cFos. In DCs, mTORC1 pathway is known to regulate IL-12 and IL-10 gene expression via NFkB. Using ChIPseq, we demonstrate significant enrichment of NFkB with IL-12a and reduced binding to IL-10 cis regulatory elements when moDC are loaded with homologous antigenic epitopes. Lastly, scRNAseq analysis of moDC loaded with homologous MHC antigens revealed enhancement of a cluster expressing cDC1 markers including Irf8, Batf3, Nfil3, Runx3, Id2, Ly75, Apol7c, Serpinb6b, Serpinb9, and costimulatory genes. Conclusion In sum, our work demonstrates that the loading of moDC with homologous MHC antigens induces skewing toward a cDC1-like phenotype. Funding Source R01AI127387 , R01AI153326 Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)

AZD5582-reactivated cells likely differ from productively infected cells 2266717

Abstract Introduction AZD5582 (AZD) is a SMAC mimetic that reverses latency by activating the non-canonical NF-κB pathway. AZD can trigger 3-4 logs transient viremia in ART-suppressed macaques; however, the reductions in the latent reservoir have been modest. Detailed analysis of the mechanisms is difficult to study due to low amplitude and fluctuating viral load signals. Methods We analyzed longitudinal data from 29 ART-suppressed, SIV-infected rhesus macaques treated with AZD5582 in combination with other agents (e.g., SIV antibodies, N-803, and/or MT807R1). We used a nonlinear mixed-effect modeling framework to fit an ensemble of mechanistic viral-dynamics models to the plasma SIV RNA and SIV CA-DNA measurements. We performed model selection using Bayesian information criteria and parameter identifiability checks, ultimately using the best models’ parameter estimates to infer the AZD5582 mode of action and treatment response mechanisms. Results The viral-dynamics model ensemble successfully reproduced the viral dynamics observed, specifically the AZD5582-associated increase in plasma SIV RNA and the changes in SIV DNA levels. Parameter estimates from the top-performing models consistently indicated that cells reactivated by AZD exhibited lower viral production and a significantly reduced death rate, ranging from 32 to 89% less than other infected cells. Conclusion Mechanistic modeling provides an explanation for the limited reduction in the viral reservoir despite the strong latency reversal achieved by AZD5582. The model revealed that reactivated cells behave differently from fully productively infected cells. This finding suggests that combining AZD5582 with other type of latency reversing treatment may improve the overall effectiveness and robustness of the drug. Funding Source R01 OD011095, R01 AI028433, R01 AI152703, U54 HL143541, UM1-AI164561, Los Alamos National Laboratory 20220791PRD2. Topic Categories Computational and Systems Immunology (COMP)

Advanced Cytometry Techniques for Immune-Based Therapy Analysis 2308503

Abstract Introduction As interest in CAR-T cells and immune-based oncology therapies rises, efficient phenotyping of cell therapy products becomes essential. This involves analyzing surface markers associated with cell type characteristics. To address this need, tools for panel design and instruments for cell interrogation must be compatible. This study highlights the combined use of an advanced panel builder to simplify assay creation with quantification using the iQue® HTS Cytometer Platform. Methods A comprehensive T cell panel was developed using the panel builder, featuring phenotype, activation, exhaustion, and memory markers, with a cell viability indicator. Two panels were created: one for iQue® 3 and a more extensive panel for iQue® 5, utilizing the enhanced laser features. Compensation particles were used to calculate spillover values using iQue Forecyt® software before applying the panel to immune cells. Human PBMCs were cultured in RPMI 1640 media with 10% serum and IL-2, with or without CD3/CD28 activation beads to activate the T cell population. Results Cells were collected and analyzed in a 96-well plate at 48- and 72-hours post-activation. CD3+, CD4+, and CD8+ T cell populations were gated, and their markers were characterized. The iQue® 5 enhanced capabilities allowed for more comprehensive analysis of activation, exhaustion, and memory markers from one sample. Data showed an increase in activation markers, and a transient increase in exhaustion marker expression over time. Conclusion In summary, the panel design tool, and the iQue® HTS Platform streamlines the creation of flexible panels for profiling immune cells. This combined approach is suitable for the generation of HTS data in 96- or 384- well throughput. The panel can be enhanced to include cytokine profiling with the iQue Qbead® immunoassay portfolio, utilizing the ability to track cell and bead populations within the same sample. Funding Source n/a Topic Categories Translational and Interventional Immunology (TI)

Genome-wide CRISPR Identification of Regulators Governing the NLRP3 Inflammasome 2331537

Abstract Introduction Dysregulated NLRP3 inflammasome activation drives chronic inflammation in autoimmune and autoinflammatory diseases. Sustained NLRP3-dependent IL-1β production promotes tissue damage, yet current therapies rely on broad immunosuppression or cytokine blockade that can impair host defense and provide incomplete disease control. Although direct NLRP3 inhibitors are emerging, their utility is limited by toxicity and an incomplete understanding of inflammasome regulation. Defining genetic networks that tune inflammasome activation is therefore critical for identifying therapeutic targets that selectively limit pathological inflammation while preserving protective innate immune responses. Methods We conducted a genome-wide CRISPR—Cas9 KO screen in human THP-1 macrophages stably expressing ASC-GFP to identify genetic regulators of NLRP3 inflammasome activation. After inflammasome activation, cells are sorted by flow cytometry based on ASC speck formation. Candidate genes were prioritized using enrichment statistics and pathway analysis. Top hits were validated using independent sgRNAs, with readouts including IL-1β ELISA and imaging-based ASC speck quantification. NF-κB phosphorylation was assessed to exclude false-positive regulators affecting inflammasome priming rather than activation. Results The screen robustly identified known NLRP3 pathway components, validating screen performance, and revealed multiple previously uncharacterized regulators spanning cytoskeletal dynamics, mitochondrial homeostasis, and ubiquitin signaling. Genetic perturbation of top candidates significantly altered IL-1β release without affecting NF-κB priming. Conclusion Our study defines a comprehensive genetic landscape governing human NLRP3 inflammasome activation and uncovers novel regulatory nodes that decouple inflammasome assembly from upstream priming. These findings provide mechanistic insight into innate immune regulation and nominate new targets for selective therapeutic modulation of inflammasome-driven disease. Funding Source n/a Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)

Single-cell mapping of stress-conditioned hematopoiesis reveals distinct molecular adaptation separating resilience from susceptibility 2267362

Abstract Introduction Chronic stress is a leading predictor of poor health, elevating risk for psychiatric, cardiovascular, neurodegenerative, and immune disorders. Stress-linked disease courses are marked by systemic inflammation, and both in humans with prolonged stress exposure and animal social-stress models show characteristic immunologic shifts (monocytosis, neutrophilia, lymphopenia). Yet how a psychological experience imprints durable biology and why genetically similar individuals diverge into resilience versus susceptibility, remains unclear. Methods We performed single-cell transcriptomics on HSPCs, progenitors, and mature lineages from control, resilient, and susceptible mice after chronic social defeat stress (CSDS; n = 3/group, 320K cells). Results two reproducible, opposing programs across the hematopoietic hierarchy. Resilient mice exhibit proteostasis/UPR buffering, orderly myeloid maturation, and a prompt negative-feedback module coupling AP-1 immediate-early genes to Dusp1, Zfp36, Btg2, and Nr4a1. In long-term HSCs, transcription-factor activity inference indicates preserved FOXO/Notch tone and fatty-acid oxidation–features of quiescence maintenance and rapid stimulus resolution. In contrast, susceptible mice display type-I interferon and viral-sensing signatures (Irf7/9, Oas1/3) together with mitotic/replication stress and mixed stemness/lineage-priming transcriptional states; TF activity highlights MYC/E2F engagement with one-carbon metabolism and glycolysis alongside strong AP-1 activation. Conclusion Together, our work motivate a conservative but innovative model: divergent outcomes arise from differences in AP-1 “dwell time” and the efficiency of NR4A-linked negative feedback. Our work suggests measurable enhancer kinetics as biomarkers and a route to rationally tune hematopoietic responses to stress. Funding Source n/a Topic Categories Hematopoiesis and Immune System Development (HEM)

Liquid Metal Composites Enabled High‐Safety Flexible Solid‐State Aluminum Batteries

ABSTRACT Rechargeable aluminum batteries (RABs) are promising for stationary energy storage due to their intrinsic safety, low cost, abundance, and use of non‐flammable chloroaluminate ionic liquid electrolytes. However, aluminum anode instability from dendrite growth and corrosion limits cycle life. This study presents a facilely fabricated Al 20 ‐LM‐Ti composite anode, featuring a structure where aluminum microparticles are semi‐embedded in EGaIn. This design not only resists electrolyte corrosion but also utilizes the fluidic nature of the EGaIn to suppress the outward growth of aluminum dendrites. Furthermore, by providing a crystallographic orientation similar to that of the subsequently deposited layer and offering higher adsorption energy for reactive ions, this anode enables uniform aluminum deposition while enhancing interfacial ion transport and diffusion. Consequently, the assembled Al 20 ‐LM‐Ti//Al 20 ‐LM‐Ti symmetric cell achieves stable cycling for over 2200, 3000, and 1600 h at high current densities of 1, 2, and 3 mA cm −2 , respectively. Leveraging this structurally robust anode, a full Al 20 ‐LM‐Ti//graphite cell operates stably for over 39 000 cycles at 1.5 A g −1 . Extreme tests under heavy striking, mechanical cutting, and burning reveal its outstanding reliability. This work holds significant implications for realizing high‐performance RABs and offers a promising strategy for anode development in other battery systems.

Azotobacter vinelandii glutaredoxin D delivers the core [Fe2S2] cluster to nitrogenase cofactor scaffold protein NifU

Effects of real-time and potential traffic congestion on network throughput

Abstract To reduce traffic congestion and improve network throughput, this study focuses on the dynamic routing process by constructing a unified path-cost function that integrates both a real-time traffic congestion index (derived from instantaneous node queue lengths) and a potential traffic congestion index (estimated from the expected number of future paths traversing each node based on active routing decisions). Through extensive simulations on Barabási–Albert scale-free network and Erdös–Rényi random network, we systematically investigate how these two types of congestion information affect network throughput. The results reveal that real-time traffic congestion is more significant than potential traffic congestion in improving network throughput. By comparison with five routing algorithms, it is found that the routing strategy considering both real-time and potential traffic congestion are more efficient. The main contribution of this work is to reveal the impacts of real-time and potential congestion on network throughput, clearly establishing their primary-secondary relationship in throughput control, and providing empirical guidelines and parameter-tuning recommendations for hybrid routing designs that combine immediate responsiveness with predictive awareness.

Neutrophils Display Limited Antiviral Activity Against HIV-1 Immune Complexes 2307573

Abstract Introduction Neutrophil antimicrobial responses are triggered by direct pathogen recognition or binding of antibody-antigen immune complexes (ICs) to cell-surface receptors. Although known to be critical for control of diverse bacterial and viral infections, neutrophil responses to HIV-1 and HIV-antibody ICs (HIV-ICs), remain poorly defined. We hypothesized that HIV-ICs enhance neutrophil antiviral activity and that antibody specificity and subclass influence virus elimination. Methods HIV-ICs were formed by incubating monoclonal antibodies (mAbs) with fluorescent HIV-1 virions. Peripheral blood neutrophils were exposed to HIV and HIV-ICs. Phagocytosis was assessed by flow cytometry and microscopy. To test viral inactivation, HIV-IC-loaded neutrophils were co-cultured with permissive cells containing an HIV-driven luciferase reporter gene. Neutrophil activation, degranulation, and reactive oxygen species (ROS) production were measured following phagocytosis. Matrix metalloproteinase-9 levels in supernatants were measured to evaluate degranulation. Results HIV-ICs formed with IgG3 mAbs induce more than double the binding and phagocytosis of HIV than IgG1 mAbs, and 30-fold more than free HIV virions. Phagocytosis effectively removed infectious HIV, though non-internalized HIV could be transferred from neutrophils to permissive cells. Surprisingly, we found that neutrophils did not produce robust ROS or significant release of cytotoxic granules in response to HIV-ICs. Consistent with these latter findings, we did not observe significant changes in the activation state of neutrophils following stimulation with HIV-ICs. Conclusion Our findings reveal that while HIV-ICs mediate neutrophil binding and phagocytosis of HIV-1, these interactions do not trigger additional antimicrobial responses. Moreover, neutrophils can transfer extracellularly bound, but not internalized, HIV-1 to permissive cells. These findings reveal that neutrophils can limit HIV transmission only through successful internalization of HIV-ICs. Funding Source NIAID P01 AI162242. H Conley is supported by NIH T32 AI007392 Topic Categories Viral Immunology (VIR)

Antibody Signatures of Illness Trajectories: Comparative FLow-based Immune Profiling (FLIP) in Long COVID 2260564

Abstract Introduction Infection-associated chronic illnesses (IACIs) such as Long COVID (LC) and Post-Treatment Lyme Disease Syndrome (PTLDS) reveal a gap in our understanding of immune resolution after infection. Some patients experience persistent fatigue, cognitive dysfunction, post-exertional malaise, dysautonomia, musculoskeletal pain, and allergy-like symptomes. Although triggered by distinct pathogens (SARS-CoV-2 for L; B. burgdorferi for PTLD), these conditions share overlapping clinical and immunological features, suggesting convergent pathways of post-infectious immune dysregulation. Current serological assays quantify bulk antibody titers but fail to resolve the functional antibody diversity that may determine recovery versus chronicity–highlighting the need for mechanistic biomarkers of disease trajectory. Methods To address this, the Tal Lab developed FLow-based Immune Profiling (FLIP), a high-dimensional serological assay quantifying pathogen-bound antibodies across IgD, IgM, IgA, IgE, and IgG1—4 subclasses using live pathogens or antigen-coated beads as bait. FLIP captures effector-function—relevant antibody heterogeneity, revealing ratiometric patterns that encode immune trajectory. We established FLIP for LC, analyzing plasma from the RECOVER cohort to characterize SARS-CoV-2—specific and total antibody distributions, and compared these with the MAESTRO PTLDS cohort, where FLIP had identified antibody ratios predictive of symptom persistence. Results Our results show that (i) FLIP can be adapted to small-particle pathogens (viruses), enabling high-resolution mapping of SARS-CoV-2—specific repertoires, and (ii) distinct ratiometric antibody architectures differentiate recovery from persistence across both patient cohorts, supporting their potential use as predictive biomarkers of post-infectious outcomes. Conclusion Our findings establish FLIP as a versatile platform for dissecting humoral immune responses and provide a foundation for predictive diagnostics and immune-targeted interventions in IACIs. Funding Source n/a Topic Categories Immune Mechanisms of Human Disease (HUM)

GLP-1 Receptor Agonists Ameliorate Obesity-Driven EAE Severity in HLA Class II Transgenic Mice 2265661

Abstract Introduction Multiple sclerosis (MS) is a chronic neuroinflammatory disease driven by genetic and environmental factors. Obesity and gut microbiota dysbiosis are emerging as key modifiable risk factors that exacerbate MS severity. The HLA-DR2.DQ6 haplotype within the HLA class II locus confers strong susceptibility to both MS and obesity. Glucagon-like peptide-1 receptor agonists (GLP-1RAs), such as liraglutide are FDA-approved anti-obesity drugs with immunomodulatory potential. This study examines whether GLP-1R activation mitigates obesity-driven EAE severity by restoring gut-immune-brain homeostasis in HLA-DR2.DQ6 class-II transgenic (Tg) mice, a preclinical model of MS. Methods HLA-DR2.DQ6 Tg mice were fed a normal chow (NC) or high-fat diet (HFD) for 8 weeks, followed by liraglutide (0.2 mg/kg, S.C.) or vehicle treatment for 3 weeks. Fecal samples were collected for microbiome profiling. EAE was induced with MOG35-55/CFA/PTX, and clinical scores were monitored (0-5 scale). On day 31 post immunization, splenocytes were stimulated (PMA/ionomycin) and analyzed by flow cytometry for pro-inflammatory CD4+ T cells. Results Liraglutide treatment significantly reduced body weight in HFD-fed mice (HFD vs. HFD + Liraglutide, p < 0.0001) but had no significant effect in NC-fed controls (NC vs. NC + Liraglutide, p = 0.088). Moreover, liraglutide markedly ameliorated disease severity in HFD-induced obese HLA-DR2.DQ6 Tg mice with EAE. Notably, liraglutide administration alleviated obesity-associated gut microbiota dysbiosis and reduced the frequency of pro-inflammatory cytokine-producing effector CD4+ T cells. Conclusion Together, these findings suggest that GLP-1RAs reprogram the gut-immune-brain axis and act as dual-acting metabolic and immunomodulatory agents that restore gut microbial balance and reduce EAE severity in HLA-DR2.DQ6 Tg mice, offering a promising strategy to mitigate obesity-exacerbated MS and related neuroinflammatory diseases. Funding Source National Multiple Sclerosis Society (NMSS) #: RG-2407-43720, U.S. Department of Defense (DoD)# HT94252510562, University of Iowa Carver College of Medicine for the Startup Fund Topic Categories Therapeutic Approaches to Autoimmunity (THER)

Rational design of RORγT small molecule modulators results in tunable LXRα pleiotropic effects in Th17 cells 2267479

Abstract Introduction RAR-related orphan receptor gamma T (RORγT), a nuclear receptor highly expressed in immune cells, is the master regulator for Th17 cell fate. RORγT dysregulation drives pathogenic Th17 phenotypes and autoimmune diseases. Directly targeting RORγT with small molecule inverse agonists has been largely unsuccessful. Therefore, we utilized rational design to improve RORγT inverse agonist effects while simultaneously tuning a pleiotropic target, Liver X Receptor (LXRα). LXR agonism suppresses Th17 inflammatory responses, resulting in new small molecules with potentially better therapeutic profiles. Methods We used Promega’s Dual-Glo luciferase assay in 293T cells for primary screening, generating EC50/IC50 values via serial dilution. Human primary CD4+ T-cells, differentiated into Th17 cells, were treated with 1 μM compound for 72h. RNA was harvested, and IL-17 ELISA was performed on supernatants. Structural studies used recombinant protein for radioligand competition and HDX-MS (Q-Exactive, automated PAL system). Results Novel compounds at 1 and 5 μM suppressed RORγT transcriptional response more effectively than parent compounds. This led to decreased RORγT transcription and IL-17 secretion, concurrent with increased LXRα activity. Although LXRα transcript decreased, its target genes were elevated, suggesting prolonged downstream activation. Structural modeling showed the ligands bind in similar LBD positions but vary in LXR pocket depth. We validated these in silico findings using recombinant RORγT and LXRα in radioligand competition assays (to determine Kd) and HDX-MS (to confirm binding sites) Conclusion Rational design of small molecule modulators enhanced RORγT inverse agonism and tuned LXRα agonism. These compounds better suppressed the pathogenic Th17 phenotype, reducing IL-17 secretion and downstream gene expression. Given LXRα’s anti-inflammatory benefits, these modulators are promising novel therapeutics. In vivo data is pending Funding Source NIH, Synkine Therapeutics Inc. Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)