Browse Articles

Spatiotemporal and molecular factors determining T cell stemness and differentiation in autoimmune Type 1 Diabetes 2328677

Abstract Introduction Type 1 diabetes (T1D) is a T cell—mediated autoimmune disease driven by β cell-specific CD8 T cells. How autoreactive T cells arise and sustain disease remains unclear. Using the non-obese diabetic mouse model of T1D, we previously identified a stem-like CD8 T cell population in the pancreatic lymph node (pLN) which initiates and sustains β cell destruction: stem T cells (TSC) self-renew and continuously give rise to differentiated progeny (TDIFF) that migrate to the pancreas and kill β cells. Spatial positioning of somatic stem cells is critical for their maintenance, and that niche restricted signals (i.e., WNT and NOTCH) regulate the balance between self-renewal and differentiation. However, if and how T cell stemness is associated with distinct intranodal positioning in pLN, and whether interference in migration disrupts differentiation, is unknown. Methods We conducted (i) paired single-cell RNA- and ATAC-sequencing, (ii) adoptive T cell transfer studies, (iii) high-resolution imaging, (iv) CRISPR/Cas9 mediated gene editing of autoimmune T cells in pLN to identify the molecular and functional characteristics of TSC and TDIFF. Results We discovered unique transcription factors and epigenetic programs governing autoimmune T cell stemness and differentiation. TSC and TDIFF express distinct chemokine receptors and integrins, suggesting that T cell stemness and differentiation are driven by intranodal positioning. Strikingly, WNT and NOTCH signaling were enriched in TSC, driving the expression of critical stem genes, thereby connecting T cell stemness to somatic stem cell biology. Pharmacological blockade and CRISPR/Cas9-mediated deletion of integrins and cell-cell interactions prevented autoimmune T cell differentiation and disease. Conclusion Our studies identify novel transcriptional regulators and niche-dependent signals that determine autoimmune T cell stemness and differentiation, opening novel therapeutic avenues for the prevention and treatment of T1D and other autoimmune diseases. Funding Source NIH F31DK141119, NIH R01AI173249, Juvenile Diabetes Research Foundation JDRF SRA-2023-1410-S-B, MSKCC Basic Research Innovation Award (BRIA), Hearst Foundation Topic Categories Lymphocyte Differentiation and Peripheral Maintenance (LYM)

Electronic Structure Modulation of Heterogeneous Cathode Catalysts for Reversible Aprotic Li‐CO ₂ Batteries: Mechanisms and Strategies

ABSTRACT Lithium‐carbon dioxide batteries (Li‐CO 2 ), featuring a high discharge voltage (∼2.8 V) and a high theoretical energy density (1876 Wh kg − 1 ), have garnered significant attention for their dual capability in energy storage and CO 2 fixation. However, the complex reaction pathways across multiphase interfaces and sluggish discharge‐charge kinetics result in poor reversibility, which severely hinders their practical application. Addressing these challenges necessitates the development of efficient cathode catalysts, whose activity is fundamentally governed by their electronic structure. In this review, we systematically elucidate the structure‐performance‐mechanism relationships of cathode catalysts in Li‐CO 2 batteries by first examining the underlying reaction mechanisms at the electrode‐electrolyte interface. We then provide a detailed analysis of how the electronic structures of heterogeneous catalysts influence discharge‐charge processes. Particular emphasis is placed on specific electronic structure modulation methods or their combinations, through strategies targeting active sites, surface morphology, and interface structure, as a pivotal route for constructing high‐performance catalysts. Subsequently, we also discuss the underlying atomic‐level origins of these modulation effects. Finally, we propose several future research directions aimed at advancing the fundamental understanding of Li‐CO 2 electrochemistry, optimizing electrocatalytic performance, and accelerating the practical implementation of Li‐CO 2 batteries.

Spacer Regulation of the Novel Pyrene‐Based Tetrapodal Self‐Assembled Monolayers for Efficient and Stable Inverted Perovskite Solar Cells and Modules

ABSTRACT Multipodal self‐assembled monolayers (SAMs) composed of π‐conjugated aromatic units have emerged as highly promising hole‐transporting layers in perovskite solar cells (PSCs) due to their excellent interfacial anchoring and scalable fabrication. However, it remains a formidable challenge to develop high‐performance tetrapodal SAMs that can simultaneously achieve ideal surface coverage, enhanced device efficiency, and improved long‐term stability. Herein, we rationally designed and synthesized two novel pyrene‐centered tetrapodal SAMs, 4PACz‐Py‐C2 and 4PACz‐Py‐C4. Spacer engineering has been employed to regulate molecular packing, facilitate hole extraction, and suppress non‐radiative recombination. The optimized PSCs based on 4PACz‐Py‐C2 achieved a power conversion efficiency (PCE) of 26.61% and maintained 90.1% of their initial PCE after 2000 h of maximum power point (MPP) tracking, demonstrating outstanding commercialization potential. Moreover, perovskite solar modules (aperture area: 21 cm 2 ) and 1.68 eV wide‐bandgap perovskite devices based on 4PACz‐Py‐C2 yielded high PCEs of 23.52% and 23.48%, respectively. This work exhibits significant application value in the development of novel multipodal SAMs for enhancing the efficiency and stability of PSCs.

The riddle of sphingolipid structure-function relationship in the nervous system

Research on creep life prediction of entangled metallic wire material based on performance degradation parameters and time–temperature superposition principle

VEGF-C enhances BALT and skews IgE responses towards a pathogenic, anaphylactic profile in mouse models of allergic asthma 2259494

Abstract Introduction Understanding how environmental allergens elicit bronchus-associated lymphoid tissue (BALT) is key to elucidating mechanisms of asthma pathophysiology; however, the extent to which different allergens elicit BALT and IgE responses is poorly understood. We previously reported that intratracheal administration of VEGF-C drives lymphangiogenesis and increases BALT and IgE, but their pathogenicity was unclear. Methods To investigate this, we exposed mice intratracheally to house dust mite, Alternaria, and ragweed allergens and assessed BALT via fluorescence microscopy. Additionally, we implemented NP-conjugated OVA to measure IgE affinity and to distinguish high affinity (anaphylactic) from low affinity (protective) IgE responses. Results All allergens induced BALT, with Alternaria eliciting a stronger response, suggesting differential immune activation and lymphoid tissue formation to environmental allergens. ELISA with NP2, NP7 and NP36 conjugated antigens showed that VEGF-C driven BALT increased the NP2-to-NP36 IgE ratio, indicating a skew towards high affinity anaphylactic IgE responses. Furthermore, following allergen inhalation, VEGF-C treated mice exhibited exacerbated hypothermia, associated with worse anaphylaxis. By contrast, no significant difference was observed between the control and VEGF-C treated groups upon intravenous allergen exposure, implying a lung-localized response. Indeed, VEGF-C treated mice showed increased airway hyperresponsiveness to increasing methacholine, indicative of exacerbated local reactivity. Finally, in B cells within the BALT, we identified Iε transcripts, a necessary event delineating B cells poised to IgE class switching. Conclusion Overall, these findings demonstrate that environmental allergens promote BALT and that VEGF-C enhances this process by driving local high affinity IgE production, anaphylaxis and airway hyperresponsiveness. These results suggest that BALT is not only a site for immune activation but also a local source of IgE-producing B cells. Funding Source Alper Fund & Nucleate DojoGrant Research Fellowship 2025 Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

Microbial Metabolite D-Lactate Enhances CD4+ T Cell Effector Function by Rewiring Metabolism Independently of Its Catabolism 2255554

Abstract Introduction Lactate profoundly influences immune cell metabolism and function by stimulating mitochondrial oxidative phosphorylation and enhancing ATP production. The effects of D-lactate on CD4+ T helper cells remain largely unexplored. Since D-lactate is produced not only in trace amounts by mammalian cells but also by gut microbiota, elucidating how it modulates T helper cell responses may reveal fundamental mechanisms of immune regulation and provide insight into disease processes such as cancer. Methods In Vitro T Cell Activation and Treatment. Metabolic Assays. Genetic Mouse Model. In Vivo Tumor Control Studies. Functional and Phenotypic Analyses. Gene Perturbation Studies. Results D-lactate enhances CD4+ T cell cytokine production in vitro and improves tumor control in vivo, which depends on mitochondrial oxidative phosphorylation and preferential fatty acid utilization. The creatine kinase energy shuttle is essential for ATP delivery in D-lactate-treated cells, and disruption of this pathway markedly diminishes D-lactate—induced effects. Using a conditional knockout mouse model of its cognate enzyme, Lactate Dehydrogenase D (LDHD), we show that LDHD is dispensable, demonstrating that the effects are a direct consequence of D-lactate and not a downstream metabolite. Finally, a surprising finding is that D-lactate-treated CD4+ T cells display a cytotoxic phenotype, producing significantly higher levels of perforin and granzyme B, and exhibit enhanced antigen-specific killing in vitro. This enhanced cytotoxicity depends on oxidative phosphorylation and the creatine kinase system and can be inhibited by blocking another strongly induced gene, fascin. Conclusion Together, these findings demonstrate that the microbial metabolite D-lactate enhances CD4+ T cell cytokine production and effector function by rewiring cellular metabolism. Both of these effects enhance the ability of CD4+ T cells to mount an efficient immune response at sites of D-lactate accumulation. Funding Source n/a Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Decoding Histone-DNA Methylation Crosstalk in Exhausted T Cells to Enhance Immunotherapy 2253691

Abstract Introduction Epigenetic scarring restricts the long-term function of exhausted CD8 T cells (TEX), impairing their ability to control chronic infections and tumors, or to respond effectively to immunotherapy. While our prior work established that de novo DNA methylation reinforces terminal exhaustion, how upstream histone modifications influence these methylation programs remains largely unknown. Defining these molecular mechanisms is essential for reversing exhaustion and enhancing the durability of T cell immunotherapies. Methods We employed a novel in vitro model of human CD8 T cell dysfunction alongside preclinical murine models of T cell exhaustion. Using integrative epigenomic approaches, we profiled H3K4 methylation states (H3K4me1/3) and DNA methylation signatures across distinct TEX subsets. To investigate functional relevance, we performed CRISPR/Cas9-gene editing, retroviral transduction, and pharmacological inhibition of histone demethylases to assess their impact on TEX functions, stemness, and response to immune checkpoint blockade (ICB). Results While distinct histone and DNA methylation landscapes defined TEX subsets in both human and murine models, H3K4me1/3–histone marks that inhibit Dnmt3a-mediated DNA methylation–were enriched at effector/memory-associated genes in cytolytic/progenitor TEX but diminished in terminally exhausted cells. Genetic or therapeutic inhibition of specific H3K4 demethylases (KDM5A/B) improved effector function and cytotoxicity in dysfunctional human CD8 T cells. In vivo, KDM5A/B targeting enhanced TEX fitness and responsiveness to anti-PD-L1 therapy during chronic viral infection and cancer. Conclusion Our findings uncover a central histone—DNA methylation circuit, regulated by KDM5A/B and DNMT3A, that drives epigenetic scarring and terminal exhaustion in CD8 T cells. Therapeutic targeting of this circuit offers a novel approach to epigenetically reprogram TEX cells and enhance the efficacy of cancer immunotherapy. Funding Source R01AI170926 (NIH, NIAID) Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

Heat can STING: Defining the relationship between heat and cGAS/STING activation in iTreg and Th1 CD4+ T cells 2260369

Abstract Introduction Heat is a cardinal feature of inflammation that is also generated by many solid tumors. We have recently shown that heat promotes Th1-mediated inflammation via cGAS/STING activation, and also decreases suppressive capacity of regulatory T cells (Tregs) with no detectable STING activation. The cGAS/STING pathway detects cytosolic nucleic acids, inducing Type I Interferon (IFN-I) production and stimulating T cell immunity when activated in innate cells. It is also highly expressed in T cells, yet the CD4+ T cell-intrinsic effects of STING remain underexplored, and are especially unclear within regulatory T cells. Methods Given the pro-inflammatory effects of heat, and the likelihood that Tregs are exposed to heat while suppressing inflammation, we explored the effects of STING and heat (39 °C) on induced Tregs (iTregs) compared to Th1 cells. Results Notably, we have found that STING activation reprograms iTregs into IFN-I-producing T helper-like cells with inflammatory function accompanied by decreased oxidative metabolism and suppressive function. Both heat and STING increased ROS and DNA damage in iTreg and Th1 cells, and activating STING at 39 °C revealed that heat potentiates STING-induced inflammation in iTregs and Th1s, but Th1s experienced significantly more cell death in response to cGAMP and/or heat. Our data show that Th1 cells have increased expression of cGAS/STING at 39 °C, and at baseline (37 °C) compared to iTreg cells, indicating a potential mechanism for the resilience of iTreg cells during cell stress responses to heat and STING activation. Conclusion These data suggest a novel axis linking heat to STING that can be leveraged to understand and modulate Treg function in inflammation and promote CD4+ T cell responses without inducing significant cell death. These findings motivate further investigation into the mechanisms intertwining STING and heat in Tregs and suggest potential synergy between temperature and Treg-targeted STING modulators for broad applications in immunotherapies. Funding Source NIAID (F31AI186436) Topic Categories Cellular Adhesion, Migration, and Inflammation (CAM)

The Influence of B-Cell Intrinsic IL-1β on the Long-Term Maintenance of Antibody Secreting Cells 2257827

Abstract Introduction Antibody secreting cells (ASCs) are an integral component of immunological memory and can play a pathogenic or protective role in the setting of autoimmunity or infection, respectively. Long-term survival of ASCs, and thus durability of the antibody response, is dependent on the microenvironment in the bone marrow (BM). In vitro studies have shown that mesenchymal stem cells (MSCs) express interleukin 1 receptor (IL1R1) and produce ASC survival factor interleukin 6 (IL-6) upon stimulation with interleukin 1β (IL-1β). IL-1β is a key pro-inflammatory cytokine that has typically been associated with innate immune cells, though our group has demonstrated B cells as a source of IL-1β in the germinal center. Thus, its presence on B cells raises questions about the role of IL-1β in modulating adaptive immune responses. As cytokines have been shown to function locally, we hypothesize ASCs as a source of IL-1β in the BM, enhancing their survival and homeostasis. Methods To explore the role of B cell derived IL-1β on ASC maintenance in the BM we utilized a murine B cell specific depletion of IL-1 β in the setting of influenza infection to assess ASC response. Results In wild type mice we observe that >90% of BM ASCs express IL-1β and that BM ASCs express IL-1β at higher levels than peripheral ASCs. In the setting of B cell intrinsic IL-1β deficiency we observe a significant decrease in all ASCs and antigen specific ASCs in the BM at 40 days post influenza infection. This decrease was specific to the BM and was not noted in the lymph node. Conclusion Hence, B cell derived IL-1β is vital for optimal long-term maintenance of ASCs in the BM post influenza infection and thus implicates the role of this cytokine in durable antibody-mediated memory. Subsequent studies will further probe the dependence of ASC homeostasis in the BM on B cell derived IL-1β as well as the potential role of agonistic effects on its cognate receptor IL1R1 on MSCs to produce IL-6 on ASC survival and maintenance in the BM. Funding Source n/a Topic Categories Lymphocyte Differentiation and Peripheral Maintenance (LYM)

Anti-integrin autoantibodies associated with ulcerative colitis inhibit mucosal TGF-beta activation 2309966

Abstract Introduction Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by inflammation of the colonic mucosa. Recent reports have shown that UC patients develop autoantibodies against the epithelial cell-specific integrin αvβ6 that can be detected up to 10 years prior to clinical diagnosis. A key function of αvβ6 is activation of the cytokine TGFβ, a central regulator of gut immunity and homeostasis. We hypothesized that autoantibodies may predispose individuals to chronic intestinal inflammation by disrupting αvβ6 activation of TGFβ. Methods Serum and mucosal biopsies from UC patients and matched healthy controls were analyzed for anti-integrin autoantibodies by ELISA, and numbers of autoantibody-producing cells by ELISPOT. The ability of autoantibodies to block TGFβ activation was assessed using patient samples. Effects of αvβ6 blockade on intestinal epithelial cell function were tested using colonic cell lines and primary human epithelial cells. Results We detected αvβ6 autoantibodies in almost all UC patients tested, confirming earlier reports. We identified αvβ6-specific B cells and autoantibodies in colonic biopsies from UC patients, demonstrating that antibodies are produced at sites of inflammation in UC. We found that IgG from autoantibody-positive UC patients inhibited αvβ6-mediated TGFβ activation and that αvβ6 blockade in human intestinal epithelial cells (IECs) decreased TGFβ-response genes while upregulating goblet cell-associated genes. In a mouse model in vivo, loss of epithelial αvβ6 caused goblet cell expansion in the colon and increased susceptibility to DSS-induced colitis. Conclusion Collectively, our data support a model in which UC-associated αvβ6 autoantibodies disrupt TGFβ signaling in IECs, predisposing individuals to colitis. These findings suggest that αvβ6 autoantibodies serve not only as an early biomarker but also contribute to development of disease and may represent a novel therapeutic target. Funding Source NIH (NIDDK), Kenneth Rainin Foundation Topic Categories Mucosal and Regional Immunology (MUC)

Serotonin receptor HTR2B signalling modulates adaptive immune response to colon cancer and metastasis 2258790

Abstract Introduction Neuro-immune communication is essential for body regulation in both health and disease. Serotonin, a neurotransmitter, influences the functions of immune cells and promotes the growth of cancer. The specific roles of serotonin receptors in immune responses and cancer progression are still unclear. Methods An orthotopic colon tumor model was developed in C57BL/6 mice by injecting the colon tumor cell line, MC38 cells. Spectral flow cytometry, multicolor immunohistological analysis, and quantitative real-time PCR (qRT-PCR) were used. Results Our analysis of TCGA colon cancer patients’ data (n = 220) revealed a significant negative correlation between HTR2B expression in tumor tissue and patient survival. Colon cancer tissue biopsies showed higher levels of HTR2B and tryptophan hydroxylase (an enzyme required for serotonin synthesis) than those in healthy tissues. Treatment of tumor-bearing mice with the HTR2B-specific agonist BW-723C86 promoted tumor growth, whereas the specific antagonist RS-127445 significantly reduced colon tumor growth and metastasis. Tumor-induced using MC38-expressing ovalbumen showed that HTR2B antagonism promotes ova-antigen-specific effector CD8 T cell response. Furthermore, HTR2B agonism in mice promoted the serum circulation of PD-L1 molecules, which were significantly reduced with the HTR2B antagonist. HTR2B-antagonist treatment enhanced CD8 T cell function by decreasing the expression of checkpoint molecules (CTLA-4, PD-1, TIM-3) and inhibiting Foxp3+ Tregs in the tumor. Combining a low-dose HTR2B Antagonist with minimal doses of checkpoint inhibitors (anti-PD1, anti-PD-L1, or anti-CTLA4 mAb) or chemotherapeutic agents resulted in significantly reduced tumor growth. Conclusion We demonstrate that colon tumors exhibit altered HTR2B expression, and targeting HTR2B promotes antigen-specific anti-tumor immunity. These results suggest that the neuro-immune axis of HTR2B signaling forms a promising therapeutic strategy for controlling tumor growth and metastasis. Funding Source GL received a Swarna Jayanti Fellowship (DST/SJF/LSA-01/2017-2018) from the Department of Science and Technology, a TATA Innovation Fellowship (HRD-16012/5/2024) from the Department of Biotechnology, and a research grant from the Science and Engineering Research Board (CRG/2022/007108), Ministry of Science and Technology, Government of India. Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Persistent expression of myeloid lineage markers in resident and circulating T cells induced by SARS-CoV-2 infection 2328943

Abstract Introduction Coronavirus disease 2019 (COVID-19) is an acute respiratory disease caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Impaired and dysregulated host immunities, such as impaired coordination and disruption of CD4/CD8 T-cell-mediated virus-specific adaptive immune responses to SARS-CoV-2, have been hypothesized as age-related risk factors in COVID-19 disease severity. However, the characteristics and heterogeneity of CD4/CD8 T cell subsets that respond to SARS-CoV-2 remain elusive. In the present study, we focused on investigating those subsets and there role in COVID-19 infection. Methods We established an age-dependent COVID-19 model by infecting middle-age mice (7-8 months old) or young mice (6-8 weeks old) with 100 or 500pfu of a mouse adapted SARS-CoV-2 virus (SARS2-N501YMA30). Lung, spleen tissues and blood harvested at 60 and 90 days post infection (dpi) were subjected to flow-cytometry and CyTOF for CD4/CD8 T cell profiling. Data was analyzed using FlowJo_v10.10.0 software. Results Only middle-age mice showed an average weight loss of 10% and 20% in low (100pfu) and high (500pfu) viral dose infected group respectively. Immune profiling revealed increase in the CD11b, CD11c expressing CD4/CD8 T cell subsets in the infected mice. These infection-prompted subsets increased significantly in middle-age mice and were found to contribute in effector functions as well as consist T cell-mediated immune memory, characterized by higher Granzyme B and Perforin expression. Conclusion This study characterizes CD11b, CD11c expressing CD4/CD8 T cell subsets with potent antiviral effects, which is in accord with the reported data of association of CD11b and CD11c T cell with increased cytotoxic activity in other viral infections like Influenza, RSV. Further analysis of these immune cells is underway to better understand their roles in driving protective or pathogenic immune responses upon SARS-CoV-2 infection in mice. Funding Source Functional Microbiomics, Inflammation and Pathogenicity- COBRE pilot grant (OGMB220226F1) (JZ); UofL starting package (F1256, F1260) (JZ) Topic Categories Viral Immunology (VIR)

From Experiment‐Driven to Theory‐ and Data‐Driven: A Computational Paradigm Shift in High‐Entropy Electrocatalyst Design

ABSTRACT High‐entropy materials (HEMs) have emerged as promising electrocatalyst platforms because compositional diversity enables tunable electronic structures and abundant active sites. With rising demands in energy conversion and environmental applications, theory now plays a central role in HEM design, in particular density functional theory (DFT), molecular dynamics (MD), and machine learning (ML). Recent advances in computational strategies for elucidating mechanisms and selecting optimal compositions are synthesized. The shift from experiment‐driven studies to proactive, theory‐ and data‐driven discovery is highlighted, enabled by the integration of high‐throughput calculations with ML for efficient screening. Method limits and key challenges are assessed, including black‐box interpretability, modeling of disorder and coverage, and gaps between theoretical models and experimental conditions, and directions in workflow standardization, open databases, and reproducible benchmarks are outlined. Building on these elements, a compact DFT‐ML‐MD closed‐loop framework is proposed that links atomic‐scale energetics to device‐level metrics, with the aim of guiding the accelerated discovery and deployment of high‐activity, durable high‐entropy electrocatalysts for sustainable energy.

Active Hydrogen Reservoir Enabled by <i>p</i> – <i>d</i> Orbital Hybridization in PdSb Metallene for Electrocatalytic Alkynol Semi‑Hydrogenation at Large Current Densities

ABSTRACT Electrocatalytic semi‐hydrogenation reaction (ESHR) represents a promising sustainable production route, making the electrocatalytic synthesis of alkenol from alkynol at near‐industrial current densities particularly significant. However, large current densities readily promote the competing hydrogen evolution reaction (HER), which consequently reduces the overall reaction efficiency. Here, we report a PdSb metallene (PdSb ene) electrocatalyst that overcomes this limitation by functioning as an efficient “active hydrogen reservoir”. The p – d orbital hybridization induced by Sb incorporation modulates the electronic structure of Pd, which facilitates water dissociation, stabilizes H* intermediates, and steers the hydrogenation pathway toward thermodynamic favorability. Operating at a current density of −200 mA cm −2 , the PdSb ene catalyst achieved the semi‐hydrogenation of 2‐methyl‐3‐butyn‐2‐ol (MBY) to 2‐methyl‐3‐buten‐2‐ol (MBE) with a 92% conversion, 96% selectivity, and 88% Faradaic efficiency, while maintaining stable performance for over 400 h. This work demonstrates that constructing an orbital‑hybridization‑driven “active hydrogen reservoir” is a viable strategy for efficient electrosynthesis under demanding conditions.

Correction: Characterization of Mast2 kinase defines structural features, regulation, and substrates

Beyond flat patching: wavelet tokens with cross-scale and decoupled attention for electricity load forecasting

Vaccination Consolidation: Dual-Engineered Vaccine Confers Protection against Yersinia pestis and Burkholderia pseudomallei Aerosol Challenge 2259579

Abstract Introduction Yersinia pestis (Yp) and Burkholderia pseudomallei (Bp), the causative agents of plague and melioidosis respectively, are both responsible for extremely high lethality. There are no FDA-approved vaccines against these pathogens, and treatments are challenging due to antibiotic resistance. Methods Here we developed a multi-pathogen vaccine against Yp and Bp. Mice were vaccinated with a nanolipoprotein (NLP) formulated with Yp Fraction 1 protein (F1), Yp low calcium response V protein (V), Bp hemolysin-coregulated protein 1 (Hcp1) as well as Bp capsular polysaccharide (CPS) admixed with CpG and aluminum hydroxide wet gel (AlOH), following a two-dose vaccine schedule. We used a model of pneumonic plague and melioidosis in which C57BL/6 mice were initially aerosol challenged with Yp, and following convalescence mice were then challenged with Bp. Results The multi-pathogen vaccine conferred 100% and 60% protection following Yp and Bp challenge, respectively. Anti-F1, -V, and -Hcp1 IgG titers in serum reached similar levels between all vaccine groups and appeared to diminish at a similar rate. The magnitude of the IFN-gamma recall response of splenocytes was less pronounced in the multi-pathogen vaccine, although it conferred similar protection as current benchmark vaccines. Conclusion The multi-pathogen vaccine was comparably protective to benchmark vaccines but with the advantage of reduced number of injections and dose sparing. These data show that the NLP platform is amenable to multi-pathogen formulations and a single vaccine regimen can protect from both pneumonic plague and melioidosis. Funding Source DTRA-JSTO Topic Categories Vaccines and Immunotherapy (VAC)

Integrin-mediated entry and fibroblast-supported retention in memory B cell residency in allergic lungs 2256174

Abstract Introduction Allergic asthma is a chronic inflammatory disease of the airway driven by allergen-specific IgE antibodies. We recently identified lung-resident memory B cells (MBCs) as a major source of allergen-specific IgE in the airway. Compared to circulating MBCs, lung MBCs upregulate integrin subunits a4 and aL. Thus, we hypothesize that integrins mediate MBC entry into the lung where the lung stroma supports MBC residency and survival. Methods To disrupt integrin-mediated interactions, we i.v. administered blocking antibodies against integrins a4 and aL during sensitization in a mouse model of airway hypersensitivity. Lung B cells were identified by flow cytometry and i.v. CD45-labeling. Allergen-specific IgE was quantified by ELISA. To analyze the lung stroma, we performed single cell RNA-seq on FAC-sorted CD45- cells from sensitized and unsensitized lungs. Gene expression and cell-cell communication analyses were performed using Seurat v5 and CellChat, respectively. Results Blocking both integrins a4 and aL, but not a4 or aL alone, significantly reduced MBCs in the lung and increased MBCs in the lung vasculature, suggesting MBCs are stuck in the lung vasculature. Notably, integrin blockade also reduced antigen-specific IgE in the airway to undetectable levels. Cell-cell communication analyses on bioinformatically paired single cell RNA-seq data on the lung stroma and MBCs predicted interactions between MBCs and lung fibroblasts expressing extracellular matrix (ECM) proteins and MBC survival factors such as BAFF. Top upregulated gene pathways in fibroblasts after allergen sensitization also included ECM synthesis and integrin-mediated cell-cell interactions. Conclusion Altogether, these results support that MBCs enter the allergic lung via upregulation of select integrins and may be retained in an ECM-rich survival niche provided by activated fibroblasts. These findings provide a mechanism for lung-resident MBC formation in allergic asthma and potential targets for disrupting pathogenic IgE responses. Funding Source R01 HL165120 Topic Categories Cellular Adhesion, Migration, and Inflammation (CAM)

Loss of Foxo3a—IL-10 antagonism promotes terminal myelopoiesis via Dgat2-mediated upregulation of lipid droplet accumulation 2253907

Abstract Introduction Haematopoietic Stem Cells (HSCs) have the potential to develop into all the blood and immune cells in the body through haematopoiesis. This stepwise differentiation of lineage-committed HSCs is primarily governed by a range of transcription factors and epigenetic modulators. However, inflammatory signals from infections and acute or chronic conditions can impact the functional and differentiation capacity of HSCs, activating the first responders and driving HSC differentiation towards myeloid cell type, triggering a state of emergency myelopoiesis, thereby disrupting homeostasis. The transcription factor Foxo3a is an important modulator of cellular processes such as cell cycle, apoptosis, and DNA repair. While Foxo3a acts as a tumor suppressor, it has also been implicated in attenuating inflammatory responses. We have previously reported that Foxo3a prevents the development of spontaneous and fulminant inflammatory response in the gut of Il10-deficient mice. Since myeloid cells, generated in Bone Marrow (BM), are the primary mediators of potent inflammatory response, we hypothesized that Foxo3a may inhibit the key cell signaling mechanisms in the BM compartment to restrict the escalation of inflammatory response in Il10-deficient mice. Methods BM cells isolated from WT, Foxo3a-/-, Il10-/- and Foxo3a-/-IL10-/- mice were used for flow cytometry, immunohistochemistry, ELISA, qRT-PCR and western blot techniques. Results Foxo3a restricts the expansion of the myeloid progenitors and mature cells, exacerbates inflammatory response in BM, regulates terminal differentiation and survival of myeloid cells, and also represses the accumulation of neutral lipids and metabolism in myeloid cells in Il10-deficient hosts. Conclusion Foxo3a attenuates the exacerbation of myelopoiesis in Il10-/- mice through the repression of Dgat2 and Calprotectin. Dgat2 catalyses the terminal step in triglyceride generation, leading to increased accumulation of neutral lipids, upregulation of cytokine expression and myelopoiesis. Funding Source NA Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)