Browse Articles

Filaggrin-deficiency drives immunopathogenic IL-18 response during in the initiation of atopic dermatitis 2256840

Abstract Introduction The skin forms a mechanical barrier against invading pathogens and environmental allergens. As such, genetic deficiencies in crucial barrier proteins such as filaggrin could result in skin barrier dysfunction. Clinically, filaggrin deficiency is correlated with predisposition to ichthyosis vulgaris (IV), increasing severity to atopic dermatitis (AD) and susceptibility to cutaneous infections. However, immunological mechanisms of how filaggrin-deficiency drives these skin disorders and augment the interactions with microbes remain unclear. Methods Using a mouse model with specific deficiency for filaggrin, we topically administered the ears with MC903 and colonized with Staphylococcus aureus to interrogate the effects on atopic dermatitis and pathobiontic bacterial colonization. Results We first show that filaggrin-deficiency results in comparable trans-epidermal water loss (TEWL) at baseline. However, filaggrin deficient (Flg-/-) mice exhibited increased inflammation and barrier dysfunction upon a biophysical challenge such as tape-stripping. Post atopic induction with calcipotriol (MC903) challenge, elevated tissue swelling and TEWL were also observed in Flg-/- animals relative to wildtype (WT) mice. The proinflammatory cytokine- IL18 was also significantly upregulated in Flg-/- mice compared to WT. Importantly, prophylactic inhibition of IL-18 significantly reduced skin swelling and restored barrier function in filaggrin-deficient mice to WT levels, underscoring its potential as a therapeutic target for inhibition during AD. Moreover, IL-18 expression was elevated in the keratinocytes in our mouse model of AD and in human AD patients. Colonization of filaggrin-deficient mice with S.aureus also resulted in the elevation of inflammatory swelling compared to WT controls. Conclusion We have thus described an animal model of skin barrier dysfunction with filaggrin-deficient mice to study the initiation events of disease and identified IL-18 as an immunopathogenic factor during atopic dermatitis. Funding Source Skin Research Institute of Singapore Joint Research Grant (SRIS_JRG_2010) Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

Sex differences in hematopoietic progenitors: defining the roles of gonadal vs chromosomal sex 2259359

Abstract Introduction Hematopoietic stem and progenitor cells (HSPC) self-renew and differentiate throughout the lifespan to maintain blood cell populations in homeostasis and regenerate after injury. HSPCs (e.g. long-term (LT) and short-term (ST) HSCs and multipotent progenitors (MPPs) express androgen and estrogen receptors. Sex differences in HSPC numbers and fitness may arise from epigenetically imprinted events originating from an original sex steroid exposure or be reshaped by the extrinsic sex steroid environment. Sex differences in HSPCs also may reflect effects of XX or XY chromosome complement. Methods We measured numbers of HSPCs in age-matched male and female mice and in Four Core Genotype (FCG) mice, which isolate the effects of chromosome complement (XX or XY) and gonadal sex (M or F), across the lifespan. To assess the relative fitness of LT-HSCs, we generated competitive bone marrow (BM) chimeras comparing male and female LT-HSCs transferred to male or female hosts, or LT-HSCs from FCG mice with identical gonadal sex, but different chromosome complement. After 4 mos, we measured their contribution to HSPCs and mature immune cells. Results Sexually mature males have more HSPCs in BM than females, with a minor elevation of LT-HSCs and ST-HSCs and a significant increase in lymphoid-biased MPP4s. In mixed BM chimeras, male LT-HSC-derived cells dominate in BM, spleen, and lung in both female and male hosts, indicating a superior intrinsic capacity to engraft regardless of the steroid environment. Analyses of FCG mice showed that HSPCs were primarily regulated by gonadal sex pre- and post-puberty, with a small contribution of chromosome complement for some subsets. Mixed competitive LT-HSC BM chimeras generated with XXF and XYF into females or XXM and XYM into males showed that sex chromosome complement alone had little effect on engraftment. Conclusion Male HSPCs have a superior cell intrinsic fitness, which may impact immune system regeneration in chronic inflammation, infection, and BM transplantation. Funding Source Oklahoma Center for Adult Stem Cell Research, AAI Careers in Immunology Fellowship Topic Categories Hematopoiesis and Immune System Development (HEM)

KRAS G12D Blocks Erythroid Differentiation and Promotes Inflammatory Pathways at the Single Cell Level in Myeloid Malignancies 2251571

Abstract Introduction Myeloid neoplasms (MN) are characterized by myeloid blast expansion that blocks hematopoietic differentiation and causes cytopenia, a major cause of morbidity and mortality. KRASG12D mutations occur in up to 15% of MN, are enriched in therapy-resistant disease, and are linked to poor prognosis. Currently, no precision medicine strategies exist for KRASG12D-mutant MN. Progress has been limited by the lack of representative models and difficulty distinguishing KRAS-mutant from wildtype cells in patient samples. Methods To address this, we used Genotyping of Transcriptomes (GoT), which co-captures single cell RNA-seq and mutational status within the same thousands of individual cells to elucidate specific KRASG12D-driven pathways in preleukemic Clonal Hematopoiesis (CH) and 3 Acute Myeloid Leukemia (AML) patient samples. We also developed a novel transplantable AdenoCreLox KRASG12D mouse model. Results In AML, mutant cells formed a distinct inflammatory, stem/progenitor-like population with elevated CD83 expression and quiescent features. In vitro, KRASG12D CD83+ cells displayed higher stemness and reduced differentiation compared to CD83− cells. An isolated KRASG12D CH sample revealed mutant cell overrepresentation in the myeloid lineages, specifically monocytes and erythrocytes. Treatment with a KRASG12D-specific inhibitor (MRTX1133) restored wildtype erythroid differentiation and downregulated inflammatory genes, including CD83. Lastly, a KRASG12D mouse model mimicking human disease with extramedullary granulocytic tumors was developed, where CD83 marked mutant cells. Resolution of these phenotypes was achieved with MRTX1133 treatment. Conclusion Therefore, KRASG12D drives erythroid differentiation block, monocytic bias, and inflammation, which MRTX1133 reverses. We identify a novel quiescent CD83+ KRASG12D progenitor population in AML and demonstrate the therapeutic potential of MRTX1133 in vivo. Additionally, targeting CD83+ quiescent cells may prevent AML progression in KRASG12D patients. Funding Source n/a Topic Categories Immune Mechanisms of Human Disease (HUM)

Olfactory receptor 2+ tumor-associated macrophages activate CD8+ T cells to suppress tumor growth 2260125

Abstract Introduction Olfactory receptor 2 (Olfr2 in mice; OR6A2 in humans) has emerged as a regulator of macrophage activity. We found that Olfr2+ tumor-associated macrophages (TAMs) are required for proper CD8+ T cell activation. Methods Using an orthotopic B16F10 melanoma model, we compared tumor growth in wild-type and Olfr2-/-mice. Bone marrow transplant experiments were performed to determine whether the phenotype was driven by loss of Olfr2 in hematopoietic cells. In vivo OT-I adoptive transfer assays were conducted to assess the ability of Olfr2+ TAMs to support CD8+ T cell priming and cytotoxicity. Additionally, RNA-seq analysis of sorted Olfr2+TAMs was performed to characterize their transcriptional programs. Gene set enrichment analysis (GSEA) was used to evaluate the transcriptional impact of Olfr2+ TAMs and their potential association with improves responses to immune checkpoint inhibitor (ICI) treatments. Results Olfr2-/- mice developed nearly twice the tumor burden of wild-type controls, a phenotype driven by loss of Olfr2 in hematopoietic cells. Tumors from Olfr2-/- mice exhibited reduced CCL2 and CXCL9 expression and diminished CD8+ T cell infiltration. In vivo OT-I adoptive transfer demonstrated that Olfr2+ TAMs are essential for supporting CD8+ T cell priming and cytotoxicity. RNA-seq of Olfr2+ TAMs revealed enrichment of antigen presentation, pro-inflammatory, and anti-tumor pathways, consistent with their enhanced antigen presentation capacity observed in vitro. GSEA further showed that the Olfr2+ TAM transcriptional signature was associated with CXCL9+ TAM—enriched tumors and improved ICI responsiveness in human melanoma datasets. Conclusion Together, these findings establish Olfr2+ TAMs as central regulators of CD8+ T cell immunity in melanoma, linking olfactory receptor signaling in macrophages to anti-tumor immune activation and potentially improved responses to ICI therapy. Funding Source n/a Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

PLA-PEG-encapsulated Chlamydia muridarum MOMP triggers strong innate immune responses alone and when adjuvanted with the mucosal dmLT in macrophages 2256388

Abstract Introduction Chlamydia trachomatis can lead to serious female reproductive tract complications, yet there is no FDA-approved vaccine against this pathogen. Here, we developed a nanovaccine (named PPrM) by encapsulating a Chlamydia muridarum (Cm) major outer membrane protein (MOMP) in biodegradable poly-lactic acid-polyethylene glycol (PLA-PEG) nanoparticles. We aimed to evaluate the effects of PPrM alone or combined with the double mutant labile toxin (dmLT) mucosal adjuvant, on the expression levels of Th1 cytokines, pathogen recognition receptors, and costimulatory molecules in mouse J774 Macrophages. We hypothesized that the dmLT adjuvant would potentiate the PPrM-induced innate immune responses that are critical for an efficacious chlamydial vaccine candidate. Methods We conducted dose- and time-dependent studies in which macrophages were stimulated with various concentrations of PPrM, MOMP, and dmLT, alone or combined, for 6, 24, 48, and 72 hours. The cell-free supernatants were used for cytokine-specific ELISAs, and the cell pellets were either stained for protein expression using Flow cytometry (FC), or the extraction of RNA for gene expression analysis using TaqMan qPCR. Results We observed that PPrM alone or combined with dmLT triggered enhanced production of MOMP-specific IL-6, IL-12p40, and TNF-α in a dose- and time-dependent fashion compared to MOMP alone or when adjuvanted. Our results also showed an enhanced upregulation of TLR-2, CD40, CD86, and CD80 expression levels with qPCR and confirmed with FC. Conclusion Overall, our data demonstrated the potentiating effects of the PPrM alone or when combined with dmLT on the MOMP-induced innate immune responses that are crucial in promoting a Chlamydial Th1 adaptive protective immunity in mice. Thus, the dmLT could be a promising mucosal adjuvant to consider in the development of chlamydial vaccines or nanovaccines. Funding Source This research was supported by the National Science Foundation (NSF) HBCU-UP (HRD-1911660) and the National Science Foundation (NSF)-EiR (2200529) grants and the Ph.D. Program in Microbiology at Alabama State University. Topic Categories Vaccines and Immunotherapy (VAC)

Upregulation of autophagy related genes in the dorsal root ganglion in CD137L KO mice, link to peripheral nerve injury induced-peripheral neuropathy 2254504

Abstract Introduction CD137 Ligand (CD137L, AKA: 4-1BBL) is a co-stimulatory molecule facilitating the activation and function of adaptive immunity. Previously we have demonstrated that CD137L knockout (KO) mice display reduced pain-like behaviors and faster recovery following peripheral nerve injury. Autophagy is a cellular process to facilitate the selective degradation and recycling of cytoplasmic contents, playing a critical cellular function in maintaining intracellular homeostasis. Increasing studies have shown the contribution of the protective effects of enhanced autophagic activities to pain-like behaviors following peripheral nerve injury. Here we examined the potential association between autophagic activities and CD137L depletion mediated pro-nociception. Methods RNA profiling on several autophagy related genes was performed via a NanoString assay in both lumbar spinal cord (LSC) and dorsal root ganglion (DRG) tissues harvested from CD137L KO mice and corresponding wild type (WT) controls. Results An overall upregulation of autophagy related genes was observed, more so in the DRGs than in the LSC, at basal levels in CD137L KO mice compared to WT mice. Particularly, we detected a significant upregulation of DRG EPG5, ectopic P-granules 5 autophagy tethering factor, a protein facilitating the fusion between autophagosomes and lysosomes. Follow-up qRT-PCR verified the upregulation of EPG5 and showed the upregulation of genes encoding EPG5’s binding partners, LC3 and Rab7, at both basal level and 14 days following sciatic nerve crush in CD137L KO mice vs. WT controls. Assessment of these autophagy factors at protein levels is on-going. Conclusion Our current results support the potential contribution of enhanced autophagic activities to reduced pain-like behaviors in CD137L KO mice. Funding Source NIH/NINDS 1R01NS098426 (PI Cao). Topic Categories Immune Mechanisms of Human Disease (HUM)

Low Temperature Growth of High‐Quality Wurtzite Ferroelectric Through Quasi‐van der Waals Epitaxy

ABSTRACT Wurtzite‐type aluminum scandium nitride (AlScN) has emerged as a potential candidate for next‐generation ferroelectrics due to large polarization, high Curie temperature and compatibility with semiconductor technology. However, strategies that enable the low‐temperature growth of high‐quality films, and the exfoliation of freestanding membranes are still lacking, largely hindering integration in functional devices. Here, we demonstrate the growth of high‐quality AlScN films at the low temperature of 150°C on substrates with distinct crystal symmetries, achieved by using a two‐dimensional transition metal dichalcogenide (TMDC) monolayer as a buffer. The high crystallinity is stemmed from the quasi‐van der Waals epitaxy, which is universally demonstrated on a wide range of TMDC materials. The TMDC buffers further enable the fabrication of freestanding AlScN membranes, exhibiting excellent ferroelectric properties including high remanent polarization, low leakage current and rapid switching kinetics. Our findings provide a low‐thermal‐budget approach with high integration flexibility to develop wurtzite‐based ferroelectric, piezoelectric, and electro‐optic devices.

Surface‐Functionalized LLZO‐Incorporated Multilayer Composite Solid Electrolytes for Dendrite Suppression and Efficient Ionic Conduction in Lithium–Metal Batteries

ABSTRACT The development of solid polymer electrolytes is central to safe, high‐energy lithium‐metal batteries (LMBs); however, persistent challenges including dendritic‐lithium‐growth, interfacial instability, and low ionic‐conductivity impede their commercialization. Herein, we report a tri‐layered composite solid electrolyte (CSE) that couples interfacial engineering with mechanical‐reinforcement to address them. The outer layers consist of PEO/LiTFSI, while inner layer comprises a PEO/LiTFSI matrix reinforced with polydopamine‐coated Li 7 La 3 Zr 2 O 12 (PDA@LLZO, 10–40 wt%) and poly(ethylene glycol)‐block‐poly(propylene glycol)‐block‐poly(ethylene glycol) (PPP). The PDA coating promotes strong hydrogen‐bonding with PEO‐matrix, leading to uniform dispersion and reduced interfacial resistance. LLZO enables percolated Li + ‐transport channels and disrupts PEO crystallinity, advancing segmental dynamics. Simultaneously, PPP elastomers offer mechanical compliance, redistribute localized stress, and dissipate dendritic intrusions to suppress crack propagation. The optimized CSE‐30 (30 wt% PDA@LLZO) exhibits an ionic‐conductivity of 5.60×10 −3 S cm − 1 at 60°C and 8.04 × 10 −5 S cm − 1 at 25°C, nearly four‐times higher than PEO, with a Li + ‐transference number of 0.81 and anodic stability up to 5.6 V vs. Li/Li + . In Li/LFP full cells, CSE‐30 delivered a capacity of 133.6 mAh g − 1 at 0.5C with 80% retention after 1000 cycles and Li/Li symmetric cells sustained over 1000 h cycling without short‐circuiting. This multifunctional CSE design advances next‐generation solid‐state LMBs by integrating efficient Li + ‐transport and mechanical resilience.

CCR4-NOT is required for suppressing pervasive transcription and retrotransposable elements

Construction, marine reworking, and stabilization of continental-shelf volcanic edifices in the Wollabong Volcanic Complex, Jeju Island, South Korea

Modeling Inflammation, Neutropenia, Bone Marrow Failure, and Lymphoproliferation caused by TLR8 (INFLTR8) in B6 Mice 2259831

Abstract Introduction Toll-like receptor 8 (TLR8) is an endosomal sensor of ssRNA expressed primarily in myeloid cells. TLR8 activation leads to expression of type I interferons and inflammatory cytokines. Recently, 12 patients who presented with neutropenia, lymphoproliferation, infections, and bone marrow failure were found to have gain of function (GOF) mutations in TLR8 (“INFLTR8”). Strikingly, many of these patients were mosaic for the mutations with variant allele frequencies of < 30% (Aluri et al; Blood 2021). It is unclear how these mutant harboring cells lead to such profound immune system dysfunction. We hypothesize that TLR8 mutant myeloid cells produce inflammatory cytokines leading to T cell activation and marrow failure. Methods To interrogate mechanisms of INFLTR8, we developed a transgenic B6 mouse model conditionally expressing wild type or GOF human TLR8 (TLR8WT or TLR8GOF) in the myeloid lineage. We verified expression of TLR8, obtained peripheral blood counts, analyzed serum cytokines, and performed competitive bone marrow transplants with peripheral blood and bone marrow chimerism tracking. Results TLR8GOF mice exhibit increased serum cytokines, cytopenias, and decreased engraftment potential in competitive bone marrow transplants. In addition, HSCs have decreased differentiation potential after transplantation. Ongoing experiments are aimed at identifying abnormal signaling pathways and cytokine production in the TLR8 GOF myeloid cells, as well as the cell non-autonomous effects on T cells and other bone marrow populations. In addition, we are testing potential anti-TLR therapies, including IRAK inhibition. Conclusion Our B6 mouse model of INFLTR8 recapitulates several hallmarks of the disease found in patients: cytopenias, inflammation, and bone marrow dysfunction. Our model reveals HSC dysfunction as an important component of the pathogenesis of this disease. Ongoing experiments will elucidate the mechanisms by which TLR8GOF cells impact HSCs and other cell populations. Funding Source Children’s Discovery Institute of WashU Topic Categories Immune Mechanisms of Human Disease (HUM)

GATA2 deficiency promotes a profibrotic program and metabolic dysfunction in alveolar macrophages 2253993

Abstract Introduction Alveolar macrophages (AMs) have homeostatic, anti-inflammatory programming to limit tissue damage against minor challenges and catabolize pulmonary surfactant. GATA transcription factors (TFs) shape immune cell fates and GATA2 is expressed in a lung-specific manner in macrophages. Both GATA2 mutations and downregulation in lung macrophages have been associated with chronic pulmonary pathologies in humans, but the role of GATA2 in AM function is not understood. Methods We generated mice with myeloid specific deletion of the GATA2 DNA binding C-terminal zinc finger domain to evaluate its role in AM homeostatic functions and responsiveness to inflammation. To assess homeostatic function, we evaluated AM phagocytic capacity, neutral lipid content, lipid uptake and processing. Given that GATA2 is downregulated in bleomycin-induced fibrosis, we leveraged IL-33 induced type 2 lung inflammation and RNA-seq analysis of sorted AMs to investigate the consequences of GATA2 deficiency on AM gene regulation. Finally, we used sea horse metabolic flux assay to address impact of GATA2 deficiency on the metabolic activity of AMs in steady state and type 2 inflammation. Results We observed that AM homeostatic functions remain unaffected in GATA2 deficiency. In contrast, RNA-seq analysis of AM revealed that GATA2 deficiency increased expression of genes associated with pulmonary fibrosis in IL-33-induced inflammation. Coincident with GATA2-dependent expression of genes in metabolic pathways, seahorse metabolic flux analysis suggests mitochondrial dysfunction in AM. AM GATA2-dependent gene networks are enriched for targets of TFs that regulate AM function, previously demonstrated to interact with GATA2 in other cellular contexts. Conclusion Our findings suggest that GATA2 supports lung-specific macrophage programming by helping to constrain AM metabolic and inflammatory responses, providing mechanistic insight into how GATA2 mutations and decreased expression may contribute to pathology in chronic lung diseases. Funding Source NIH/NHLBI R01HL162658 Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)

Activated MrgprD+ neurons shift γδ T cell responses and suppress imiquimod-induced dermatitis 2256517

Abstract Introduction Psoriasis is a chronic autoimmune skin disorder marked by excessive IL-17-driven inflammation and pruritus. Although intense itching is a key disease feature, the contribution of specific subsets of itch-inducing neurons to skin immunopathology is unknown. Methods This study employed a mouse model of psoriatic-like pathology induced by topical application of imiquimod (IMQ) to investigate the role of type 1 non-peptidergic (NP1) afferents bearing the Mas-related G protein-coupled receptor D (MrgprD). Results Although IMQ application reduced the epidermal density of MrgprD+ skin afferents, optogenetic or pharmacological activation of NP1 neurons before IMQ exposure significantly ameliorated epidermal thickness and psoriasiform clinical score. Conversely, ablation of MrgprD+ afferents resulted in increased skin inflammation after eight days of IMQ application. Data show that optogenetic or pharmacologic stimulation of NP1 neurons attenuated neutrophil skin influx, IL-17 cytokine responses, and γδ T cell accumulation in skin-draining lymph nodes (sdLN). Pre-emptive stimulation of NP1 neurons reduced γδ T cell-derived IL-17 and amphiregulin (Areg), but increased secretion of the immunosuppressive cytokine IL-10, and elevated γδ T cells expressing IL-13 and the transcription factor GATA3. Conclusion These data support a model wherein NP1 afferents that promote immunoregulatory responses by modulating γδ T cells are lost in the context of psoriatic inflammation. Funding Source National Institutes of Health (grant no. 1K99AI187730-01A1) Topic Categories Neuroimmunology (NEUR)

Does TCR signaling have to be so exhausting? The T cell adaptor Gads skews CD8 T cells towards exhaustion 2259399

Abstract Introduction Cytotoxic T lymphocytes (CTL) may limit tumor growth by responding to neoantigens. Yet within the tumor, chronic antigen recognition triggers a hyporesponsive state (exhaustion), in which multiple immune checkpoints repress CTL activity. Downstream to the TCR, a cascade of tyrosine kinases triggers the assembly of a signalosome, nucleated by three adaptor proteins, SLP-76, LAT and Gads. Whereas LAT and SLP-76 are absolutely required for TCR responsiveness, Gads performs a modulatory role, encompassing both positive and negative regulatory functions. Rationale TCR signaling is a key driver of tumor immunity; yet also induces exhaustion. We propose to uncouple these responses, by moderate perturbation of the TCR signaling pathway. Methods We inducibly deleted Gads in developmentally normal OT-1 T cells. Gads-deficient T cells were clearly marked by the expression of tdTomato. OT-1 T cells were then expanded and differentiated ex vivo, under conditions of acute or chronic exposure to their cognate antigen. Results Gads was largely dispensable for the antigen induced proliferation and differentiation of OT-1 T cells into perforin- and granzyme-expressing CTL. Upon restimulation, Gads-deficient OT-1 CTL matched or exceeded wild type cells in antigen induced degranulation, production of cytokines, and killing of OVA-expressing target cells. Remarkably, deletion of Gads appeared to render the cells exhaustion resistant. Following chronic antigen stimulation the frequency of PD-1 hi - TIGIT hi cells was markedly reduced in Gads-deficient OT-1 CTL, whereas the PD-1 lo - TIGIT lo population markedly increased. Conclusion Our data strongly support the possibility of uncoupling antigen-induced effector functions from antigen-induced exhaustion. Funding Source The Israel Science Foundation Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

Uncovering the immunological determinants of progressive liver disease in X-linked Myotubular Myopathy 2260077

Abstract Introduction X-linked myotubular myopathy (XLMTM) is a fatal cogenital neuromuscular disease caused by mutations in MTM1. While adeno-associated virus (AAV) gene therapy has shown promising outcomes in the first clinical trial for XLMTM, its progress has been halted by unexplained and often lethal hepatotoxicity. XLMTM is hallmarked by an accumulation of phosphatidylinositol 3-phosphate, which is a known regulator of macrophage phagocytic activities. Given that Mtm1 is also highly expressed in resident liver myeloid cells, we hypothesized that MTM1 deficiency disrupts intrinsic myeloid regulatory processes, creating a hyperinflammatory microenvironment that sensitizes the liver to gene therapy-associated injury. Methods We compared wild-type (WT) and Mtm1 knock-out (KO) mice challenged with H1N1 infection or bacterial endotoxemia (LPS) starting at postnatal day 21 to unmask latent immunopathology. Plasma cytokines analysis, liver histopathology and immunophenotyping were performed at the clinical endpoint. Results Following H1N1 infection, KO mice exhibited reduced survival (within a week post infection) and heightened liver inflammation characterized by F4/80+ myeloid cell infiltration alongside a systemic cytokine storm. This hyper-inflammatory state was starkly highlighted during endotoxemia, where a sublethal dose of LPS for WT mice was fatal to all KO mice within four hours and associated with a 2-fold increase in plasma IL-6 concentrations. This extreme sensitivity to immune stimuli is consistent with the predicted hyper-inflammatory state of myeloid sentinels due to the lack of MTM1. Conclusion The absence of MTM1 heightens the susceptibility to severe, immune-mediated inflammatory damage during early life, underscoring the urgent need for immunomodulatory co-therapies. Future work using macrophage models will serve as a crucial platform to test targeted immunomodulatory therapies designed to prevent this lethal inflammatory response and improve the safety of AAV gene therapy for XLMTM patients. Funding Source CIHR Topic Categories Immune Mechanisms of Human Disease (HUM)

Sex-Specific Effects of Pyraclostrobin Exposure on Hematopoiesis and Thymic Development in Mice 2260076

Abstract Introduction Populations with high pesticide exposure face elevated risks of immune and hematologic disorders, yet the mechanisms remain unclear. Pyraclostrobin (PYRA), a fungicide known to disrupt mitochondrial function, may alter hematopoietic and thymic processes. We hypothesized that PYRA induces mitochondrial stress leading to immune dysregulation in a sex-dependent manner. Methods Eight-week-old C57BL/6 mice were exposed to PYRA (10—100 mg/kg b.w.) for 14 or 30 days via intraperitoneal injection. Hematologic profiles were obtained by complete blood count, while flow cytometry assessed bone marrow progenitors, thymic and splenic cell populations. Results PYRA exposure at 10 mg/kg altered T lymphocyte populations in both differently, suggesting sex-specific immune modulation. Males showed increased MPP2 and decreased MPP3 frequencies, with reduced Lin⁻c-Kit+Sca1⁻ progenitors; females exhibited decreased ST-HSCs, increased GMP%, and decreased MEP%. Thymic analysis revealed increased total thymocyte counts in males, including CD8+SP cells, while females showed selective CD8+SP increases. Conclusion PYRA disrupts hematopoietic and thymic development in a sex-dependent manner, potentially through mitochondrial dysfunction. Ongoing gene expression analysis will clarify mitochondrial—hematopoietic interactions, enhancing understanding of pesticide-induced immune and marrow failure mechanisms. Funding Source California Institute for Regenerative Medicine (EDUC5-13686) (J.O.M.); UCM Committee on Research Faculty Grant (J.O.M.); Fulbright Philippines Fellowship (M.G.R.) Topic Categories Hematopoiesis and Immune System Development (HEM)

Defining the role of continued antigen engagement in regulating tumor-specific CD8+ T cell differentiation, migration, and survival 2256732

Abstract Introduction In chronic infections or cancer, stimulated CD8+ T cells progress along a trajectory towards terminal exhaustion in sites of antigen abundance. However, how these cells respond when antigen recognition is lost has not been concretely elucidated. Methods The Masopust lab generated a UBC-CreERT2 x P14 fl/fl mouse model that allows for the inducible excision of P14 TCR to precisely answer these questions, which has been used successfully in the setting of acute and chronic infections (unpublished work). Here, we combined this mouse model with the KP-NINJA tumor model (Fitzgerald et. al., 2021) that develop autochthonous lung tumors that progress slowly and express the gp33/H-2Db epitope that is recognized by the P14 TCR. Results Preliminary results showed successful infiltration and activation of these transgenic T cells in the KP-NINJA tumor microenvironment as well as accumulation within the tumor-draining lymph node following adoptive transfer. After three weeks of antigen exposure, the TCR was eliminated from 50% of transferred T cells and flow cytometry of the tumor, tumor-draining lymph node and additional tissues was performed one-week post-excision. TCR-negative T cells persisted within solid tumors and draining lymph node, although their phenotype was distinct from co-transferred TCR-positive P14 T cells. TCR-negative cells had decreased PD-1 and TOX expression in the tumor and tumor-draining lymph node and increased CXCR6 and CD127 expression within these tissues. Conclusion Ongoing studies will define tumor-specific T cell differentiation and fate after TCR excision, investigate changes to cell localization, and test functional potential. This work will add to our understanding of the development of T cell exhaustion and the plasticity of lineage commitment in cancer to better inform future anti-cancer therapeutics. Funding Source n/a Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

IL32 contributes to endometriosis pathogenesis through the regulation of cytokine production and improved macrophage survival 2256204

Abstract Introduction Endometriosis involves the ectopic growth of endometrial-like cells, often in the ovaries and peritoneal cavity, leading to pain and infertility in many patients. Chronic inflammation plays a central role in endometriosis pathogenesis. Upon interrogation of an endometriosis scRNA sequencing dataset, we found IL32 to be one of the most highly expressed cytokines in endometriosis compared to eutopic endometrium and unaffected ovary tissues. IL32 is an understudied cytokine elevated in several inflammatory diseases. In some contexts, IL32 positively regulates production of IL1α, IL1β, IL6, TNFα, and IL8, but its specific role in endometriosis is unknown. Methods To establish the effect of IL32 on immune cells, we tested unstimulated, IL32-treated, stimulated, and stimulated+IL32 conditions on whole human PBMCs in 18hr cultures, and sorted human PBMCs in 7-day cultures. Cytokine expression was measured using RT-qPCR. Proliferation, viability, and activation markers were quantified using flow cytometry. Results IL32 treatment induced a 200-fold increase in IL1β expression and a 12-fold increase in IL6 expression. This increase was dampened but remained significant in stimulated cells. 7-day treatment with IL32 did not affect differentiation of T, B, or NK cells. However, viability of unstimulated T cells was increased 3.4-fold, with similar effects on B (1.7-fold), NK (1.5-fold), and myeloid cells (2.6-fold). Notably, IL32 increased the viability of stimulated myeloid cells 6-fold, whereas other stimulated immune cell types were unaffected. Conclusion Inflammatory IL32-inducible cytokines are highly transcribed in endometriosis M2 macrophages. We hypothesize that IL32 contributes to endometriosis pathogenesis by inducing inflammatory cytokine production and cell survival in macrophages, possibly through the regulation of NFkB signaling. Our ongoing research is focused on deciphering the downstream targets of IL32 through CITE-seq profiling of IL32-treated cells. Funding Source n/a Topic Categories Cytokines and Chemokines and their Receptors (CCR)

O ₂ ‐Tolerant Electroreduction of Dilute CO ₂ to Formate at Industrial Current Density by a Kinetic Molecular Sieving Strategy

ABSTRACT Electrochemical CO 2 reduction must move beyond purified CO 2 to use real‐world sources like flue gas or captured CO 2 . But such low‐concentration feeds pose two problems: residual O 2 poisons the reaction, triggering competing oxygen reduction reaction, cutting carbon efficiency, and degrading the catalyst, while low CO 2 concentration limits mass transfer and conversion. We solve both with a kinetic molecular sieve: polyethylene glycol‐coated bismuth nanoparticles (Bi@PEG). Under simulated flue gas (15% CO 2 , 5% O 2 , 80% N 2 ), Bi@PEG demonstrates record‐breaking performance for CO 2 electroreduction to formate, achieving a Faradaic efficiency of 94.1 ± 0.6%, a current density of 0.91 A·cm −2 , and a single‐pass CO 2 conversion of 72.5%, and maintains this performance even at 8% O 2 . Mechanism studies show the PEG layer selectively admits CO 2 (small size, quadrupole moment, strong Lewis acid, base interaction with ether oxygens; binding energy −27.4 kJ mol −1 ; diffusion barrier 0.57 eV), resulting in interfacial CO 2 enrichment. In contrast, O 2 transport is significantly impeded due to a higher diffusion barrier (0.83 eV), weak binding affinity (−3.0 kJ mol −1 ), and steric hindrance. By overcoming the dual challenges of low CO 2 concentration and oxygen interference, this work establishes “armored catalysis” as a universal approach for electrochemical CO 2 conversion using realistic, low‐concentration, oxygen‐containing carbon sources.

Molecular Interfacial Engineering of Lithiophilic Protection Layer Realizing 600 Wh kg ⁻¹ Anode‐Free Lithium Metal Batteries

ABSTRACT Anode‐free lithium (Li) metal batteries (AFLMBs) can achieve higher energy densities at lower costs and easier production processes, but the uneven plating of Li leads to dendrite growth, making safety issues unavoidable. Here, we propose a convenient and scalable molecular interface engineering strategy: the 5‐methyl‐1H‐tetrazole (MTZ) molecule forms chemically bonded, stable self‐assembled monolayer (SAMs) interface on Cu foil surfaces, thereby producing modified Cu foil (MTZ‐Cu). Anchored by strong Cu─N bonds, the SAMs not only introduce high‐density nucleation sites with molecular precision but also promote preferential decomposition of LiNO 3 in electrolytes, forming a stable solid electrolyte interface that enhances plating uniformity and reversibility. When used in combination with LiNi 0.8 Co 0.1 Mn 0.1 O 2 and LiNi 0.9 Co 0.05 Mn 0.05 O 2 cathodes, the assembled 8.44 Ah and 9.96 Ah MTZ‐Cu‐based anode‐free pouch cells achieve benchmark energy densities of 505.31 Wh kg total −1 and 605.96 Wh kg total −1 for 100 cycles, respectively. This work demonstrates the advantages of molecular interface engineering in constructing practical AFLMBs, with the potential for large‐scale production to meet commercial applications.