Browse Articles

Influenza-driven hematopoietic stem cell reprogramming accelerates atherosclerosis 2259380

Abstract Introduction Hematopoietic stem cells (HSCs) are the continual source of all hematopoietic cells in the mammalian adult and persist for the entire lifespan. As such, HSPCs are exposed to a lifetime of stimuli. Far from inconsequential, it is increasingly understood that these exposures can epigenetically reprogram HSCs. This alters the fate and inflammatory phenotype of their progeny, which may have important consequences on the progression of chronic conditions like atherosclerosis. Although systemic infections by pathogens like Mycobacterium tuberculosis are well-known inducers of HSC rewiring, far less is known about how more constrained infections that do not directly replicate in the bone marrow may affect HSPCs. Methods WT and Ifnar1-/- mice were infected with influenza A virus (IAV). 28 days post-infection either ATAC-Seq was performed on sorted HSCs to describe epigenetic changes, or the bone marrow (BM) was transplanted into irradiated LDLR-/- hosts that were then fed a high cholesterol diet for 12 weeks. Effects of IAV infection on atherosclerosis were then determined by flow cytometry and histology. Results Antiviral type I interferon production generated in response to IAV infection reprograms HSCs. This reprogramming elicits circulating monocytes with a heightened interferon stimulated gene (ISG) signature that enhances their accumulation within atherosclerotic plaques, increases local macrophage proliferation, and promotes plaque destabilization. HSCs from Ifnar1-/- mice are protected from this rewiring. BM transfers from infected WT, but not Ifnar1-/-, mice confirmed that the pro-atherogenic effects of IAV was dependent upon HSCs, rather than local effects on the aorta or plaque. Interestingly, this phenotype required the recently described CD319+ pro-DC3 that became infected in the lung, trafficked to the BM, and locally sourced the IFN-I. Conclusion Our findings elucidate novel facets of stem cell biology and hint at why IAV infection greatly underscores cardiovascular disease risk. Funding Source Supported by the NHLBI/NIH, the Charles H. Revson Foundation, and the CIHR. Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Discovery, characterization and preclinical evaluation a novel engineered Fc-fused IgE cleaving enzyme for the treatment of IgE-mediated diseases 2253523

Abstract Introduction A novel Fc-fused bacterial-derived IgE cleaving protease was identified and engineered using our proprietary IMPACT platform. Through our machine learning enabled platform, the IgE protease was engineered to reduce immunogenicity and improved manufacturability while maintaining potency. It selectively cleaves human and non-human primate IgE, eliminating IgE from circulation and subsequently, from the cell-surface providing a novel therapeutic opportunity to treat IgE-mediated inflammation. Methods The IgE protease was characterized in vitro to determine its ability to cleave soluble and membrane-bound IgE using plate-based MSD assays and cell-based FACS assays. Reduced immunogenicity was confirmed in T cell proliferation assays Results Pharmacokinetics, pharmacodynamics and in vivo efficacy were tested using relevant preclinical models. The engineered IgE protease shows extended pharmacokinetics and efficacy in humanized mouse models of local and systemic acute anaphylaxis (PCA and PSA). In a rat allergic asthma model, it shows reduction of soluble IgE levels and lower eosinophils counts in bronchoalveolar fluid. Additionally, we observe a clear PK/PD relationship and reduction of serum IgE in non-human primates Conclusion Given its ability to simultaneously address multiple aspects of IgE pathogenesis and its efficacy in preclinical models of anaphylaxis, the engineered Fc-protease offers a new approach to targeted therapy for allergic and atopic diseases where IgE is a key driver Funding Source n/a Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

Anomalous Crystallinity and Magnetism in Chemically Disordered Coherent Heterostructures

ABSTRACT High‐entropy oxide (HEO) thin films uniquely superimpose exceptional chemical disorder with exceptional crystalline quality and coherence—an intersection we term anomalous crystallinity that arises from coupled structural, chemical, and valence degrees of freedom unique to the high‐entropy and entropy‐stabilized conditions. Here, we demonstrate unexpected and predictive control of this state using formulation, epitaxial constraints, and kinetic arrest of metastable macrostates. Specifically, aliovalent cation substitutions, tightly controlled substrate temperatures, and conditions favoring significant adatom kinetic energy, can program the out‐of‐plane lattice parameter of coherent rock salt HEOs while preserving in‐plane epitaxial pinning to MgO. We highlight the exemplar (ScMgCoNiCuZn)O/(CrMgCoNiCuZn)O (JSc/JCr) system where Sc and Cr substitution into the rock salt structure produces pseudomorphic heterostructures between individual antiferromagnets, sustaining an exceptional 5.5% out‐of‐plane lattice parameter difference and enabling abrupt interfaces across which the Co valence switches from mostly 2 + to an even 2 + /3 + mixture. The JSc/JCr valence interface heterostructure is accompanied by a 2 × exchange bias boost compared to single‐layer constituents, that could be attributed to enhanced uncompensated spins in the layers themselves or around the buried JSc/JCr interface. These results establish pseudomorphic valence interfaces with anomalous crystallinity as a source of new magnetic macrostates that host emergent magnetic and spintronic functionality.

Metallothionein‐Inspired Dual‐Stage Ion‐Regulatory Coatings With Infection‐Triggered Bactericidal Activity and Long‐Term Antifouling Protection

ABSTRACT The long‐term failure of implantable stents originates from static protection that cannot adapt to the temporal shift of primary risks from early‐stage infection and late‐stage biofilm–mineral occlusion. Inspired by the dynamic metal homeostasis of metallothioneins, we propose a β ‐hydroxy thioether–based ion‐regulatory network that programs competing binding sites with distinct kinetic and thermodynamic preferences, thereby embedding an intrinsic functional clock into an otherwise static material. As a proof of concept, silver is employed as a representative ion to demonstrate how conventional metal bactericides can be transformed into stage‐adaptive defense factors. Initially, the system is dominated by labile hydroxyl complexation, triggering silver ion release under infection‐associated acidification and enabling rapid bactericidal clearance. Over time, the system shifts toward thermodynamically favored thioether coordination, which becomes dominant and reprograms the coating, resulting in bacterial repulsion and mineral exclusion at sub‐bactericidal ion levels. The stage‐adaptive protection is validated in methicillin‐resistant Staphylococcus aureus ‐infected wound and long‐term (3‐month) bladder indwelling models. This work establishes time‐programmable ion regulation as an extensible design concept for adaptive biomaterials capable of coping with evolving biological environments.

Correction: Clostridioides difficile TcdB induces expression of its receptor (CSPG4) through a noncanonical Hippo signaling mechanism

Quantifying vaccination thresholds and roll-out delays in an influenza transmission model with waning and immune boosting

Single-Cell Analysis Reclassifies Eczematous Mycosis Fungoides as Severe Atopic Dermatitis 2259810

Abstract Introduction Mycosis fungoides (MF), the prevalent subtype of cutaneous T-cell lymphoma (CTCL), primarily affects the skin and progresses systemically over time. Early-stage MF diagnosis relies on immunohistochemistry, T cell receptor (TCR) gene rearrangement testing, and clinical evaluation. However, in the clinic settings, we observe eczematous MF (eMF) patients who meet early-stage MF diagnostic criteria but exhibit phenotypes resembling atopic dermatitis (AD), and refractory to dupilumab. This study investigates the molecular characteristics of eMF in comparison to AD and classic MF, providing insights into its distinct pathophysiology and potential therapeutic implications. Methods Skin biopsies were collected from seven AD patients and eleven eMF patients. Paired single-cell RNA sequencing (scRNA-seq) and single-cell TCR sequencing (scTCR-seq) were conducted to evaluate transcriptional profiles and T-cell clonality. Publicly available MF and AD scRNA-seq data were used for comparative analysis. In addition, spatial transcriptomic profiling was performed to validate. Results Comparative transcriptomic analysis showed that the molecular profiles of T cells in eMF resembled those in AD rather than in conventional MF. Furthermore, in eMF, we observed oligoclonal T-cell expansions, which were not found in conventional MF both in scRNA-seq and spatial transcriptomic data. These expanded cells were predominantly Th22 cells, identified as the primary producers of IL-13, a key cytokine in AD pathophysiology. Conclusion eMF diagnostic phenotype resembles conventional MF, and AD primarily due to the hyperproliferation of Th22 cells and their expression of IL-13. In this context, this mechanism underscores the superior efficacy of Upadacitinib, which could target Th22 differentiation, over Dupilumab. As a result, our findings indicate that eMF is not cancer, but a Th22-mediated AD endotype. Funding Source n/a Topic Categories Immune Mechanisms of Human Disease (HUM)

Heightened Krüppel-like-factor-6 alters Treg lipid metabolism in autoimmune hepatitis 2253895

Abstract Introduction In autoimmune hepatitis (AIH), regulatory T cell (Treg) impairment contributes to T effector-mediated liver damage and is linked to altered response to aryl hydrocarbon receptor (AhR), a transcription factor that modulates Treg immune responses upon binding its canonical partner, aryl hydrocarbon receptor nuclear translocator (ARNT). AhR also binds to Krüppel-like-factor-6 (KLF6) that modulates the expression of genes involved in lipid metabolism, on which Tregs rely for function. We investigated if KLF6 alterations contribute to Treg dysfunction in AIH. Methods Tregs were isolated from the peripheral blood of AIH patients and healthy subjects (HS). Treg KLF6 levels were measured by qPCR and flow cytometry. Intrahepatic KLF6+ Tregs were identified by immunofluorescence. Lipid peroxidation was measured by flow cytometry using BODIPY 581/591 C11 in KLF6 siRNA-treated Tregs. Treg suppressive function was tested in co-culture experiments, measured as inhibition of CD4+CD25- responder cell proliferation. Results KLF6 is upregulated in AIH Tregs at mRNA and protein levels. KLF6+ Tregs are more frequent in liver biopsies of AIH compared to control patients. Compared to HS, AIH Tregs display heightened intracellular lipid peroxidation and higher oxidized-to-non-oxidized lipid ratio, which is directly correlated with ALT levels. Silencing KLF6 downregulates lipid peroxidation and ameliorates suppressive function in AIH but not HS Tregs. Analysis of publicly available datasets derived from RNAseq studies conducted on Tregs from healthy subjects showed that high KLF6 levels are associated with gene sets linked to T cell activation and inflammation, including PI3K, ERK and Notch signaling pathways. Conclusion AIH Tregs show upregulated KLF6 and increased lipid peroxidation. Blocking KLF6 limits lipid peroxidation and enhances Treg suppression, suggesting that aberrant KLF6 impacts Treg function by altering lipid peroxidation. Blocking KLF6 shows therapeutic potential by rebalancing Treg lipid metabolism. Funding Source NIH R01DK124408 Topic Categories Immune Mechanisms of Human Disease (HUM)

Tmem119+ microglia controls blood-brain barrier disruption through MHC class I restricted antigen presentation in a CNS vascular disease model 2255918

Abstract Introduction CD8 T cells are key immune cells in viral clearance, targeting infected cells following recognition of MHC class I restricted antigen presentation. Previous work has determined that microglia and perivascular macrophages are essential for normal CD8 T cell responses against neurotropic viral infection, indicating that cells at the neurovascular unit can act as antigen-presenting cells. However, the specific importance of microglia MHC class I restricted antigen presentation to brain-infiltrating CD8 T cells has been difficult to define. Methods To address this question, our laboratory generated novel single MHC Class I conditional knockout mice in which H-2Kb or H-2Db can be deactivated specifically in Tmem119+ microglia with tamoxifen administration. Recombinant Theiler’s murine encephalomyelitis virus (TMEV) encoding the model OVA antigen enabled analysis of virus antigen-specific CD8 T cells restricted to H-2Kb class I molecules while Daniel’s strain TMEV H-2Db class I molecules enabled analysis of Db:VP2 specific CD8 T cells. Results Our results revealed profound differences in the response of CD8 T cells upon deletion of MHC class I molecules on microglia. Conditional knockout of H-2Kb in Tmem119+ microglia reduced Kb:OVA epitope specific CD8 T cells in the brain compared to Cre negative littermate controls, and BrdU staining revealed differences in T cell proliferation. Meanwhile, mice with deletion of Db in Tmem119+ microglia had reduced levels of perforin in Db:VP2 CD8 T cells. Furthermore, in a model of CNS vascular disease, the deletion of H-2Db of Tmem119+ microglia reduced CD8 T cell numbers in the brain, as well as the blood-brain barrier (BBB) breakdown observed by a FITC albumin assay. Conclusion These findings demonstrate discrete roles for specific MHC Class I molecules on microglia during CNS viral infection. This data will further our understanding of brain infiltrating CD8 T cell responses in neurologic diseases as well as the regulation of BBB by microglia. Funding Source R01 NS 103212 R01 NS122174 Topic Categories Neuroimmunology (NEUR)

Endothelial Cell MHC Molecules are Necessary and Sufficient to Reject 3D Printed Human Skin Grafts in an Advanced Human Immune System Mouse 2259219

Abstract Introduction Allogeneic skin is among the tissues most prone to rejection. This need has driven development of synthetic skin substitutes. There are a number of different approved synthetic skin substitutes but none of them are completely satisfactory. Here we aimed to develop a humanized mouse model to study the process of skin graft rejection using bilayered 3D-printed skin grafts implanted on MISTRG6 immunodeficient mice. Methods Vascularized skins were 3D-printed using single donor human fibroblasts, pericytes, keratinocytes and endothelial cells (ECs), the latter either unmodified (WT-ECs) or deleted of MHC molecules (KO-ECs). Adult MISTRG6 immunodeficient mice neonatally inoculated with adult human hematopoietic stem cells (HSCs) received 3D-printed skin graft allogeneic to the HSCs and were boosted 3 weeks post-grafting with human PBMCs autologous to the HSCs. Results HSC inoculation alone produced low levels of circulating human myeloid and lymphoid cells without affecting grafts; PBMC boosting increased circulating human CD4+ T cells and dramatically boosted Granzyme B-producing CD8+ T cells only in mice with WT-EC grafts. These grafts became infiltrated by human macrophages, dendritic cells, CD4+ and CD8+ T cells, and showed evidence of rejection. Shared T cell clones were present in skin and spleen indicative of systemic alloresponse. KO-EC grafts had minimal infiltration of graft or spleen without signs of rejection despite MHC molecule expression on other graft cell types. Conclusion In our model we generated a rejection response against 3D-printed skin grafts involving human myeloid cells and lymphocytes and showed that ECs are necessary and sufficient to trigger graft rejection of bioengineered tissue lacking passenger leukocytes. Funding Source NIH 1R01HL169238 Topic Categories Transplantation Immunology (TRAN)

Dopamine Activates Dual Caspase and Granzyme B Pathways for Gasdermin-Mediated Inflammasome Signaling 2250456

Abstract Introduction Beyond its role in motor control, dopamine (DA) exhibits species-specific immunoregulatory functions controlling inflammation. We previously showed that DA induces inflammatory responses in primary human monocyte derived macrophages (hMDMs) through NF-κB-mediated activation of the NLRP3 inflammasome. Methods hMDMs from healthy individuals were exposed to DA (1 µM) for 5 hours, followed by BzATP (200 µM), a potent P2X7 receptor agonist, for 1 hour to stimulate NLRP3 activation. High-content imaging, immunoblotting and qPCR were then used to assess distinct stages of NLRP3 activation. Additionally, pharmacological inhibition studies were performed to determine the contribution of specific proteases to DA-mediated inflammasome activation. Results Our findings showed that DA-mediated inflammasome signaling involves gasdermin-D (GSDMD) cleavage, as well as the unique cleavage of gasdermin-B (GSDMB), a human-specific protein. Pharmacologic inhibition showed this dual cleavage occurs through parallel pathways: caspase-mediated GSDMD cleavage and novel granzyme B (GZMB)-driven GSDMB cleavage. Cleaved GSDMD translocates to the plasma membrane after initial mitochondrial localization, however GSDMB N-terminus persists at mitochondrial membranes, promoting sustained mtDNA release. This differential localization creates a positive feedback loop amplifying inflammasome signaling while maintaining low pyroptotic cell death. Conclusion These findings demonstrate that DA coordinates mitochondrial dysfunction with NLRP3-mediated GZMB-induced GSDMB cleavage, revealing potential therapeutic targets for inflammatory diseases characterized by elevated circulating dopamine. Funding Source n/a Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)

Differential spleen immune signatures and germinal center responses during acute infection with two clinical prevalent Orientia strains 2260067

Abstract Introduction Scrub typhus is an emerging and neglected tropical disease caused by Orientia tsutsugamushi (Ot). Immunity in scrub typhus patients is known to be short-lived; however, its underlying mechanisms remain unclear. No reports have examined humoral immune signatures to clinically prevalent Ot strains. Methods In this study, we used Ot Karp and Gilliam strains and focused on splenic B cell and germinal center (GC) responses during acute infection in C57BL/6 mice for IF, RNAseq, and FACS analyses during acute infection. Results With the same infectious dose, Karp resulted in high tissue bacterium burdens and 50% mortality rates, Gilliam infection was self-healing with limited bacterium growth. Yet, Gilliam induced strong splenic B cell responses, as judged by total numbers of B cells, follicular B cells, and marginal zone B cells. Given that Karp- but not Gilliam-infected spleens displayed GC disorganization/loss and MZ abrogation, we compared splenic RNAseq profiles. On day 4 post-infection, Karp induced significant elevation of inflammation biomarkers (Ccl2, Il33, Ifng) and inflammatory pathways (Il1, Il6, Tnf, Ifng), the characteristics of severe scrub typhus. IPA analysis revealed Karp-induced neutrophil activation/degranulation and defense response pathways, which were in sharp contrast to Gilliam-induced upregulation of phagocytosis signaling pathways. Flow cytometry confirmed significantly higher influx of activated phagocyte subsets (neutrophils, M1 macrophages, and inflammatory monocytes) during Karp infection than Gilliam infection, indicating excessive inflammatory infiltration in severe infection. Conclusion Collectively, this study provides the first lines of evidence for Ot strain-related, cellular and humoral immune signatures, which help understand differential host immune responses during acute scrub typhus. Funding Source N/A Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

Utilizing uLIPSTIC to identify T cell interactions during Mycobacterium tuberculosis infection 2259762

Abstract Introduction Tuberculosis (TB) is a major threat to global health, with >1 million deaths/year. Optimal TB vaccine design is hampered by gaps in understanding the mechanisms and limitations of TB immunity. CD4 T cells are essential for TB immunity but do not reliably eliminate the pathogen. Therefore, it is critical to identify factors that promote and restrict T cell interactions and functions in vivo. Methods The ‘uLIPSTIC’ (Universal Labelling Immune Partnerships by SorTagging Intercellular Contacts) system enables labelling of cells that interact with a cell of interest by transferring a biotin tag, for identification and characterization by flow cytometry or single cell sequencing. We adapted uLIPSTIC to identify cells that interact with Mtb-specific CD4 T cells in the lungs. We generated C7 TCR transgenic mice that produce ‘donor’ CD4 T cells that label interacting ‘acceptor’ cells after T cell adoptive transfer. Results During the peak of T cell responses to Mtb at 28 days post-infection, we found that CD11b+CD11c+ monocyte-derived lung macrophages (MDMs) are the most frequently T cell-interacting cells: 54% of this cell population were biotin+. Of the Mtb-infected MDMs, 23% were biotin+ while 54% of the Mtb-uninfected (bystander) MDMs were biotin+. Conclusion This suggests that T cell recognition of Mtb-infected cells is impaired and that most Mtb-specific CD4 T cell interactions are futile, since prior work has established that direct cognate interactions between CD4 T cells and Mtb-infected cells are essential for optimal control of infection. Single cell RNA sequencing is ongoing to further characterize the population of cells that are interacting with Mtb-specific CD4 T cells. The results generated by experiments with the Mtb-adapted uLIPSTIC system will identify determinants associated with T cell mediated immune control of Mtb infection and inform host-directed therapies and ongoing vaccine development. Funding Source NIH U01 AI166309 Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)

Hypertensive Mice Display Decreased Antibody Responses to COVID-19 Vaccination 2253714

Abstract Introduction Hypertensive patients have decreased responses to nearly all COVID vaccines, reflected in increased hospitalization. These studies are largely observational, and the reason why hypertensive patients develop lower antibody responses is not known. We used a mouse model to assess the mechanisms of decreased responses to vaccination during hypertension. We hypothesized that hypertensive mice would show dysregulation of CD4+ T cell populations that may contribute to decreased antibody titers. Methods Hypertension was induced via subcutaneous implantation of osmotic minipumps containing Angiotensin II. One week after induction of hypertension, normotensive and hypertensive mice were vaccinated with two doses (prime-boost twenty-one days apart) of the Pfizer mRNA BNT162b2 vaccine. Two weeks after the boost, serum spike-specific antibody titers and follicular helper T cell numbers in spleens and draining lymph nodes were assessed by CD4+ T cell tetramer staining and flow cytometry. Spike-specific T cell cytokines were also assessed. Results Hypertensive mice showed significantly lower spike-specific and RBD-specific IgG antibody titers than normotensive mice, recapitulating the decreased antibody responses seen in hypertensive humans. Spike-specific antibody titer correlated negatively with systolic blood pressure. Hypertensive mice showed decreased spike-specific CD4+ T cells twenty-one days following prime only and decreased vaccine-specific follicular helper T cells after prime-boost, while spike-specific T cells from normotensive mice produced higher titers of IL-4. Conclusion Our results show dysregulation of vaccine-specific CD4+ T cell numbers and cytokine production during hypertension may be contributing to decreased antibody responses after vaccination. This research will broadly advance our understanding of CD4+ T cells in hypertension and is the first step in creation of vaccines that protect hypertensive patients from greater disease burden of COVID-19. Funding Source R01 AI166756-01A1 and U2C/TL1 Deep South KUH PRIME U2C DK133422 & TL1 DK139566 from the NIH/NIDDK Topic Categories Vaccines and Immunotherapy (VAC)

Bio‐Inspired Dual‐Gradient Aerogel Enables Sustainable Freshwater Production and Energy Harvesting

ABSTRACT Solar‐driven interfacial evaporation and moisture‐electricity generation offer promising routes to sustainable freshwater and energy production, yet their integration into a single water and electricity co‐production system (WECPS) has remained largely unrealized. Here, we rationally design a dual‐gradient aerogel (DGA) with engineered ion and water gradients that enables long‐term salt‐resistant solar evaporation alongside high‐performance moisture‐electricity generation. The ion gradient, created through asymmetric ion doping with two surfactants, drives directional ion diffusion to enhance electrical output, while the water gradient, arising from hydrophilicity differences and asymmetric porosity, sustains continuous water and ion transport and induces the Marangoni effect for uninterrupted evaporation. As a result, the DGA‐based WECPS delivers power densities up to 324‐fold higher than homogeneous aerogels and maintains stable solar evaporation for seven days in saline environments. An outdoor DGA‐array WECPS further demonstrates simultaneous freshwater production and energy harvesting under real conditions. These findings establish a practical pathway toward efficient, self‐sustaining water–energy co‐production technologies.

High Performance and Circularly Polarized Mechanoluminescence From Noncentrosymmetric Crystals With Pronounced Macroscopic Polarity

ABSTRACT Organic mechanoluminescent (ML) materials convert mechanical stimuli into light emission without photon excitation, offering opportunities for sustainable optoelectronics and flexible sensing. Yet, ambiguous mechanistic understanding limits structure to property relationships and hinders the rational design of high‐performance ML materials that combine durability, sensitivity, thermal tolerance, and polarization control. Herein, a general design strategy is presented based on chiral and supramolecular synergy, in which chirality enables symmetry breaking while directional supramolecular interactions amplify macroscopic polarity in noncentrosymmetric crystals. In such crystals, ML‐activity is governed by the net macroscopic rather than the molecular polarity. By constructing a zipper‐like supramolecular hydrogen‐bonding network, the resulting crystals show bright ML visible under ambient light, persistent emission after 90 min of friction, a low force threshold of 0.05 N, and thermal robustness up to 162°C. Modulating supramolecular interaction strength further enables tribochromic ML. Moreover, the chiral and polar crystal architecture affords circularly polarized ML (CPML), providing a mechanically driven route to polarized emission. To the best of our knowledge, this is the first example of purely organic CPML. This study establishes a general chiral‐polar supramolecular design strategy for high‐performance organic ML and supports their potential in advanced luminescent applications.

Structural and mechanistic insights into the VP14460-VP14465 effector-immunity module of the Vibrio parahaemolyticus type VI secretion system

Investigating the role of G-quadruplex-associated duplex stem loops in Trabectedin’s mechanism of action

Oxysterol-Mediated Modulation of NFï•«B -Linked Systemic Inflammatory Response in a Neonatal Mouse Model of Intestinal Perforation 2259826

Abstract Introduction Neonatal intestinal perforations are a major complication of preterm birth, strongly associated with mortality and neurodevelopmental impairment (NDI). Our prior work links intestinal perforation to NFκB-mediated inflammatory injury in the subventricular zone (SVZ), a neural stem cell niche critical for brain development. We hypothesize that the choroid plexus (ChP) mediates SVZ injury through NFκB-activated monocyte/macrophage trafficking after modeled intestinal perforation (MIP), and that modulation of this inflammatory cascade by 20α-hydroxycholesterol (20HC), a breast milk—derived oxysterol with anti-inflammatory activity, protects the SVZ. Methods Using single-nucleus RNA sequencing (snRNA-seq) and spatial transcriptomics, we observed peripheral monocyte/macrophage transit through the ChP and colonization of the SVZ after MIP, resulting in cytokine exposure, ependymal activation, astroglial scarring, and reduced progenitor production. For transcriptomic analyses, ChP samples were obtained from control, MIP-induced, and 20HC+MIP-treated mice. Neonatal mice received daily subcutaneous 20HC (100 mg/kg/day in MCT oil) from postnatal day 3 (P3); MIP was induced on P5, and ChP harvested 24 h later for scRNA-seq to characterize immune activation. Complementary in vitro studies used 20HC-pretreated macrophage and microglia stimulated with lipopolysaccharide (LPS) to assess NFκB-linked cytokine expression by qPCR. Results MIP induction in P5 mice caused bacterial seeding in brain, lungs, and spleen within 48 hours and elevated NFκB-linked cytokines (TNFα, IL-1β, IL-6) across organs. 20HC treatment significantly reduced cytokine expression, preserved SVZ integrity, and decreased inflammatory pathway enrichment in ChP macrophage clusters. In vitro, 20HC suppressed IL-1β and IL-6 via NFκB inhibition. Conclusion These findings identify the ChP as a mediator of inflammation-induced SVZ injury and highlight 20HC as a promising therapy to protect the developing brain after neonatal intestinal perforation. Funding Source Pathogenic Mechanisms of Inflammatory Subventricular Zone Injury in Preterm Infants-National Institutes of Health (5R01-NS140419-02) Topic Categories Neuroimmunology (NEUR)

Defining pulmonary immune responses in microbially experienced mice 2254009

Abstract Introduction Mouse models are essential tools in research, yet their relevance to humans is limited by the artificial conditions under which they are raised. The contrast between humans’ constant exposure to diverse microbes and the highly controlled environments of animal models remains a major barrier to translational research. To bridge this gap, specific pathogen-free (SPF) mice can be converted into microbially experienced (ME) mice through exposure to various microorganisms. These mice more closely resemble an adult human-like immune system, though many aspects of the model are still unknown. While current ME studies have centered their attention on the adaptive immunity, emerging evidence suggests key alterations in the innate immune compartment of the ME model. Methods Here, we generated ME mice by sequential infections with model organisms for common human pathogens (Murine gammaherpesvirus 68, Murine hepatitis virus A59, Heligmosomoides polygyrus). We then examined their pulmonary immune environment and responses to respiratory infections. Results Our recent work revealed innate cell shifts in ME mice, including a decrease in alveolar macrophage, nerve- and airway-associated macrophage, and an increase in interstitial macrophage populations in comparison to SPF mice. During Influenza A virus infection, ME mice displayed heightened inflammatory signatures and greater immune cell infiltration in the lung tissue, while sustaining a reduction of macrophage and monocyte populations. Conclusion Together, these results demonstrate that microbial experience significantly reshapes innate immunity in the lungs, highlighting possible crucial cell components for modeling an adult human-like immune system in vivo. This model provides a valuable platform for better understanding host—pathogen interactions and may improve the translation of preclinical findings to human disease. Funding Source n/a Topic Categories Viral Immunology (VIR)