Browse Articles

Neutrophil Activation is Associated with Decreased Dengue Vaccine Replication in Human Recipients 2307750

Abstract Introduction Dengue virus (DENV) is a mosquito-borne flavivirus that impacts over 50% of the global population. A better understanding of DENV-specific immune responses is needed to improve vaccines. Antibody-dependent neutrophil phagocytosis has been associated with protection against hemorrhagic fever, yet excessive neutrophil activation contributes to severe dengue, and the phenotypes of protective neutrophils remain undefined. To characterize how neutrophils respond to DENV, we evaluated neutrophil phenotypes in dengue vaccine recipients and in vitro. Methods 10 participants, with distinct DENV exposure histories, were vaccinated with a monovalent DENV3 vaccine. Cellular neutrophil markers were measured by flow cytometry at baseline (day 0) and on days 1 and 9 post-vaccination. Neutrophils from healthy donors were stimulated in vitro with different DENV serotypes, and their phenotypes were evaluated by flow cytometry. Results Following DENV3 vaccination, the total neutrophil population from all recipients showed elevated SYK and decreased CD33 expression indicating activation and maturation. When compared to participants with high vaccine viremia (N = 7), those with low viremia (N = 3) had increased expressions of CD16 and CD15 and lower CD62L on day 1. Furthermore, low viremic participants had increased CD63 in SYK positive neutrophils on day 9. In-vitro, neutrophils exposed to DENV4 survived up to 96 hours post-stimulation with no evidence of viral infection at various multiplicities of infection (MOI 1-17). Conclusion Neutrophils from participants with low viremia show increased activation, maturation and degranulation supporting their protective role in dengue. Healthy donor neutrophils responding to dengue virus in vitro will be used to characterize how sera from participants with high or low vaccine replication alters neutrophil activity. Overall, a better understanding of neutrophil responses to DENV can inform therapeutic options. Funding Source Intramural Research Program of the National Institutes of Health, NIH Bench-to-Bedside Program Funds No. 994875, NIH Director’s Challenge Innovation Award, ReVAMPP grant 1 U19 AI181960-01, and P01 AI106695. This project has also been funded in part with f Topic Categories Viral Immunology (VIR)

Time to initial infusion therapy in Primary Immunodeficiency: A community-based retrospective analysis 2328544

Abstract Introduction Common Variable Immunodeficiency (CVID) and Specific Antibody Deficiency (SAD) require lifelong management to minimize recurrent infections. While immunoglobulin replacement therapy (IgRT) is standard of care, initiation criteria remain heterogeneous. Literature offers conflicting guidance on whether therapy is driven by serological criteria (IgG levels) or clinical manifestation of immune incompetence. This study evaluates the relationship between baseline IgG, clinical encounter frequency, and therapeutic timing. Methods A retrospective analysis was conducted on 26 patients (CVID n = 18; SAD n = 7; undefined n = 1) at a community-based immunology clinic. Variables included baseline serum IgG, unique clinical visits prior to IgRT, and the interval between presentation and first infusion. Non-parametric methods (Spearman correlation, Mann-Whitney U, Kruskal-Wallis) were employed due to non-normal distribution. Results The cohort was predominantly female (84.6%, n = 22) and geriatric. Mean baseline IgG was 619 ± 165 mg/dL; mean interval to therapy was 210 ± 159 days (median: 171). No significant correlation existed between baseline IgG and time to IgRT (r=-0.15, p = 0.478), indicating hypogammaglobulinemia severity did not predict urgency. Conversely, a significant positive correlation was observed between unique clinic visits and time to infusion (r = 0.56, p = 0.004), suggesting patients with complex clinical courses experienced longer delays. No significant differences occurred based on therapy type, age, or sex. Subcutaneous immunoglobulin (92.3%) and home infusion (96.2%) were preferred. Cost concerns (30.8%) and prophylactic antibiotic preference (11.5%) contributed to delays. Conclusion Baseline IgG levels did not correlate with IgRT timing, while clinic visits were significantly associated with longer delays. Findings suggest clinical complexity influences timelines more than serologic thresholds, reflecting management reactive to accumulating encounters rather than driven by serologic criteria. Funding Source GC Biopharma Topic Categories Translational and Interventional Immunology (TI)

De-orphanizing CD271: a novel regulator of T cell function 2300697

Abstract Introduction Co-signaling molecules are central regulators of the immune system, positively and negatively tuning immune cell activation. Many co-signaling molecules belong to the immunoglobulin or tumor necrosis factor receptor superfamilies and are being targeted in the clinic to reinvigorate anti-tumor immunity. However, the cognate receptor of several family members with co-inhibitory activity remains unknown. Among these, CD271, the low-affinity nerve growth factor receptor, is expressed by immunomodulatory cells and cancer cells. While CD271 expression in melanoma correlates with a poor response to immune checkpoint blockade, its impact on T cell function is not well characterized. Therefore, we sought to determine if CD271 directly interacts with T cells to modulate their activation. Methods The impact of CD271 on T cell activation was assessed in vitro. We stimulated mouse and human T cells with plate-bound αCD3/αCD28 in the presence or absence of CD271-Fc. T cell proliferation and cytokine production were assessed by flow cytometry. To identify CD271 partners, we performed cell-based binding assays as well as a CRISPRa-based protein interaction screen. Results We find that CD271 inhibits T cell proliferation in vitro. We confirmed that CD271 binds to human CD80, but that this interaction does not account for the inhibitory effect of CD271. To further investigate which receptor interacts with CD271, we optimized a CRISPRa protein interaction platform that enables robust expression of all known surface receptors. Using CD271-coated beads, we enrich cells expressing CD271 ligands. Conclusion We identified CD271 as a novel immunoregulatory protein that can directly inhibit T cell activation in vitro. We are developing scalable, cell-based assays to systematically identify CD271 binding partners as well as de-oprhanize co-signaling molecules within the immunoglobulin and tumor necrosis factor receptor superfamilies, offering insights into immune regulation and new targets for immune checkpoint blockade. Funding Source Canadian Institutes of Health Research Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)

You are what you eat: Short-term western diet rewires neutrophil metabolism and enables Staphylococcus aureus to suppress NETosis 2254949

Abstract Introduction Immunometabolism ties diet to frontline antibacterial defense. Neutrophils rely on glycolysis to power the oxidative burst and on mitochondrial metabolism to drive neutrophil extracellular trap (NET) release. We asked whether brief exposure to a high-fat, high-calorie western diet (WD), in the absence of obesity or diabetes, is sufficient to alter neutrophil function during Staphylococcus aureus infection. Methods C57BL/6 mice were fed a WD for 2 weeks, then challenged systemically with S. aureus. Outcomes included survival, weight loss, organ bacterial burdens, and organ-specific neutrophil function. Ex vivo, neutrophil metabolism was quantified by extracellular flux analysis and effector functions (oxidative burst, NETosis) quantified by flow cytometry after S. aureus stimulation. Results In a 4-day systemic S. aureus infection model, short-term WD worsened infection outcomes, with higher bacterial burdens in the liver. Ex vivo, fatty acid oxidation (FAO) supports NETosis, indicating that fatty acid availability can fuel this effector program. However, despite increased fatty acid availability in mice on a western diet, NETosis was decreased because S. aureus exploits WD-derived fatty acids to generate or modify lipoproteins that actively suppress NET release. In addition, neutrophils from WD-fed mice display a diminished oxidative burst, consistent with Randle cycle-driven substrate competition that diverts metabolism away from glycolysis-dependent NADPH oxidase activity. Conclusion Together, these findings reveal a rapid, diet-driven vulnerability in innate immunity that S. aureus can leverage. Rather than fueling NETosis through FAO, the same fatty acids are used by S. aureus to blunt NET release, while the Randle cycle dampens the oxidative burst. Defining how diet shifts neutrophil fuel choice and how S. aureus capitalizes on that shift points to metabolic and nutritional strategies to restore NETosis and oxidative burst during infection. Funding Source NIH T32 IMP, NIH 1R35GM15838 Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

Paneth cell dysfunction regulates host response to SARS-CoV-2 infection 2260975

Abstract Introduction The extreme variability of infection severity between SARS-CoV-2 patients suggests that complex mechanisms regulate host responses to this respiratory pathogen. We addressed the role of the intestinal epithelium in host susceptibility and responses to SARS-CoV-2 and focused on Paneth cells. These cells of the small intestine are specialized in the production of antimicrobials, and their dysfunction is often associated with inflammatory bowel diseases. Methods Wild-type C57BL/6 and Paneth cell KO mice of both sexes were infected with the mouse-adapted SARS-CoV-2 MA10. Body weight, body temperature, and behavior were monitored to assess the severity of diseases. Early host responses to infection were determined by flow cytometry analysis of peripheral blood leukocyte subsets, viral load in lung tissues and the profile of host mRNA responses. We also quantified anti-SARS-Cov-2 antibody responses in the bloodstream and mucosal tissues. Results Loss of Paneth cells in the Paneth cell KO mice is associated with a dysbiosis broadly characterized by significant decrease in the amount of Bacteroidota. The profile of innate immune cells was also altered in the gut and lungs of Paneth cell KO mice. In response to SARS-CoV-2 infection, Paneth cell KO mice developed an early increase in the number of blood neutrophils, eosinophils, non-classical monocytes, T cells and B cells compared to the wild-type mice. In contrast, the early blood response of control wild-type mice was characterized by a significant increase in the number of monocytes, specifically classical monocytes. The profile of host mRNA responses 3 days post infection and the magnitude and profile of systemic and mucosal anti-SARS-Cov-2 antibody further confirmed the influence of Paneth cells on the outcome of SARS-CoV-2 infection. Conclusion These findings highlight the importance of gastrointestinal health in shaping innate immune cells in the airways and host response to respiratory viruses. Funding Source NIH PO1AI175399, T32 fellowship Topic Categories Viral Immunology (VIR)

Resonant Cavity‐Enhanced Intermolecular Charge‐Transfer Absorption for Near‐Infrared Photon Upconversion and Single‐Detector Imaging

ABSTRACT Organic semiconductors offer compelling advantages for facile and scalable optoelectronic integration, yet their limited absorption range constrains their applicability in near‐infrared (NIR) photonic technologies. Here, we report an organic upconversion device (OUD) that effectively harnesses the inherently weak but spectrally broad charge‐transfer (CT) absorption to convert NIR radiation into visible light. A resonant optical microcavity is strategically engineered to selectively amplify the CT absorption band and to establish optical isolation between the organic photodetector (PD) and the organic light‐emitting diode, thereby enhancing light‐coupling efficiency while suppressing reabsorption losses. The device achieves an impressive P–P conversion efficiency of 16.9% under 980 nm NIR illumination, despite the constituent materials lacking intrinsic absorption at this wavelength. Moreover, by simply adjusting the cavity thickness, an efficient OUD operating at a detection wavelength of 1550 nm is successfully developed for the first time. In addition, single‐detector NIR imaging is demonstrated using large‐area devices equipped with dot‐matrix connecting electrodes (DMCEs) without needing complex readout integrated circuits (ROICs) to scan signals. This work unveils the potential of intermolecular CT absorption as a versatile platform for applications in NIR sensing, upconversion, and imaging.

Utilizing Rationally Designed Photosensitizers to Drive Divergent Immunogenic Cell Death in Photoimmunotherapy

ABSTRACT Photodynamic therapy (PDT)‐based photoimmunotherapy represents a promising modality for cancer treatment, combining the precision of PDT with the sustained efficacy of immunotherapy. A key innovation in this field involves the use of organic photosensitizers to induce immunogenic pyroptosis. However, the fundamental question of whether type I and type II PDT elicit equally potent immune responses remains unresolved. To address this, we developed a series of A‐D‐A structured organic photosensitizers via rational donor–acceptor engineering. This molecular strategy enables precise control over the photodynamic pathway by fine‐tuning the intramolecular charge transfer strength, thereby establishing a platform for systematically comparing their immunogenic potential. Our mechanistic investigations reveal a critical distinction: type I‐dominant photosensitizers are more effective than their type II‐dominant counterparts at triggering caspase‐1‐mediated pyroptosis. This pyroptotic cascade stimulates the release of damage‐associated molecular patterns and pro‐inflammatory factors, culminating in potent immune activation. As a result, the leading type I photosensitizer is more capable of inducing a systemic antitumor immune response and suppressing distant tumors under a low‐power 808 nm photoirradiation. Overall, this work not only decouples the immunogenic roles of type I and type II photodynamics but also provides a rational design strategy for advanced photoimmunotherapy agents.

Post-disaster refeeding influences the effects of fasting duration on food craving: evidence from EEG beta-band analysis

Structural Insights and Immunogenic Enhancement of KRAS Neoantigen Recognition by TCRs in Cancer Immunotherapy 2260081

Abstract Introduction For over 30 years, KRAS, a key oncogene, was deemed “undruggable” due to its intracellular nature and lack of a suitable binding site, posing a challenge for monoclonal antibody and small molecule targeting. Immunotherapy offers a promising approach by leveraging T cell receptor (TCR) recognition of mutant KRAS peptides presented by human leukocyte antigen (HLA) class I on cancer cell surfaces. Driver mutations like KRAS-G12D generate public neoantigens shared among patients, making them ideal targets for T cell therapy. Methods We investigated the structural and biophysical basis for the specificity of five patient-derived TCRs that recognize the KRAS-G12D neoantigen presented by HLA-A11. To define their binding mechanisms, we solved the crystal structures of three representative TCRs in complex with KRAS-G12D/HLA-A11 and measured their binding affinities using surface plasmon resonance (SPR). Results All five TCRs recognize KRAS-G12D with high specificity. Structural analysis revealed a large conserved conformational shift in the peptide upon TCR binding, with residues A5 and D6 reorienting from an exposed to a downward-facing position, adopting a polyproline type II conformation, indicating a shared recognition mechanism. Conclusion Building on these insights, we synthesized N-amino-modified KRAS peptides designed to stabilize this conformation and test whether pre-paying the entropic penalty enhances TCR binding. These findings lay the groundwork for engineering a KRAS superagonist peptide and advancing T cell-based immunotherapies targeting KRAS. Funding Source NIH-CBBI fellowship Topic Categories Vaccines and Immunotherapy (VAC)

The Female Reproductive Tract is a Sex-Specific Site for Rheumatoid Arthritis Specific Biomarkers 2334718

Abstract Introduction Women have a three-fold higher rate of rheumatoid arthritis (RA) as compared with men, and several reproductive factors are correlated with increased risk of RA in women. RA autoimmunity can develop when citrullinated (cit) proteins are generated at a mucosal surface by peptidylarginine deiminase (PAD) enzymes. Anti-citrullinated protein antibodies (ACPAs) are produced in the mucosa and when they become systemic they trigger joint inflammation. Neutrophil extracellular traps (NETs) can generate cit-proteins in RA patients and are present in mucosal surfaces, including the female reproductive tract (FRT). Shared mucosal sites have yet to explain the sex disparity in RA, leading us to hypothesize the FRT mucosa is a sex specific site of cit-protein generation, ACPA production, and NET formation. Methods Cit-proteins were identified by mass spectrometry from FRT fluid (FRTF) collected at day 25 of the menstrual cycle in RA positive women (RA+) and healthy controls (HC) and from mice during the estrous cycle. ACPA were quantified via the anti-CCP assay (humans) and from wild type (wt) and PAD2/4 double knockout (DKO) female mice using an in house ELISA specific to individual cit-proteins. NETs were visualized in mouse FRTF and from isolated neutrophils via confocal microscopy. Results RA+ women FRTF cit-proteins were elevated compared to HC with many cit-proteins also present in wt mouse FRTF. RA+ FRTF ACPA were significantly elevated compared to HC, while DKO mice had significantly decreased FRTF ACPA to cit-fibrinogen and NETs compared to wt. Conclusion The FRT is a sex-specific site of cit-protein generation, ACPA production, and NET formation. RA+ women have significantly elevated cit-proteins and ACPA compared to HC in FRTF. The wt mouse FRTF citrullinome is comparable to that of the human. ACPA specific to individual cit-proteins are quantifiable with our ELISA. Female PAD2/4 DKO show decreased ACPA production and NET formation compared to wt female mice. Funding Source Wyoming IDeA Networks for Biomedical Research Excellence (INBRE) Topic Categories Basic Autoimmunity (BA)

Effects of the fermentation products of Agave Tequilana inulin on allergic inflammation and mast cell activation 2261171

Abstract Introduction Agave inulin is a fructose-based prebiotic found in Agave Tequilana blue var. Weber exclusively from Jalisco, Mexico. The consumption of prebiotics by microbiota generates fermentation products (FPs), such as short-chain fatty acids (SCFAs). SCFAs travel from the gut to the bloodstream, exerting multiple effects on the immune system. Type I hypersensitivity reactions (allergies) are initiated by allergen-induced immunoglobulin E (IgE), which binds to the high-affinity IgE receptor (FcεRI) at the surface of mast cells (MCs). A second exposure to the allergen (antigen, Ag), IgE/Ag conjugates, and promotes FcεRI crosslinking, activating a signaling cascade leading to MCs degranulation and the release of preformed mediators like β-hexosaminidase, inducing inflammation. Methods We administered Agave Tequilana inulin as an oral pretreatment to C57BL6/J mice and determined its effect in the passive cutaneous anaphylaxis (PCA) reaction. To evaluate the participation of FPs in the observed effects, mice feces were harvested and fermented with inulin under in vitro anaerobic conditions. FPs were then used to pretreat bone marrow mast cells (BMMCs) for 24h. The effects of one of the FPs were analyzed by performing long and short-term exposure of bone marrow-derived mast cells (BMMCs) to sodium Butyrate (Bt). Results Inulin consumption reduced inflammation in a dose-dependent manner, except at the highest concentration tested. FPs treatment reduced FcεRI-induced β-hexosaminidase release. A 24h-long Bt treatment decreased FcεRI-induced and phorbol-myristate acetate/A23187-induced degranulation of BMMCs. Bt treatment reduced FcεRI γ subunit protein expression and blunted calcium mobilization. Fifteen min-long exposure to Bt also reduced BMMCs degranulation, affected calcium mobilization, and increased tubulin acetylation. Conclusion Results suggest that Agave inulin consumption reduces allergic inflammation through the production of FPs that modify the FcεRI signaling system. Funding Source SECIHTI, Cinvestav Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)

Dietary alterations in gut microbiota impact anti-tumor immunity: towards novel strategies to boost cancer immunotherapy 2267281

Abstract Introduction Dietary factors could profoundly shape host immunity and gut microbiota and disease. High salt intake has been shown to be detrimental in autoimmune conditions by directly affecting the immune cell balance or indirectly altering gut microbiota and metabolites. We have recently demonstrated that a high salt diet (HSD), could be beneficial in cancer by promoting enhanced antitumor immunity through modulation of myeloid-derived suppressor cell (MDSC) function. Methods We investigated different tumor transplantation models in mice by using various microbial, immunological, bioinformatics and molecular biology state-of-the-art techniques. Results Here we show that HSD can further boost the efficacy of checkpoint inhibitors and the gene expression analysis of MDSCs from tumor bearing mice revealed that HSD disrupts key immunosuppressive signaling pathways in vivo. Interestingly, the effect of HSD on tumor growth is highly dependent on the gut microbiota. The inhibitory effect of salt intake on tumor growth was absent in germ-free mice and profiling of the gut microbiota revealed significant changes upon HSD. The salt mediated inhibitory effect on tumor growth could be transmitted by fecal microbiome transplantation to animals receiving a regular diet and metagenomic analysis revealed specific microbial signatures contributing to this effect. Importantly, the administration of a single identified microbial taxa alone results in delayed tumor growth by reducing MDSC-mediated immunosuppression in tumor-bearing mice. Conclusion Overall, our data suggest that salt-sensitive changes in the gut microbiota could potentially be explored to inhibit tumor growth and boost checkpoint inhibitors. Thus, our findings may have critical relevance for cancer immunotherapy. Funding Source FWO Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

Contribution of Influenza H5 Head and Stalk Domains to the Development of Functional Non-Neutralizing Antibodies Following Mucosal rH5-NE Vaccination 2333118

Abstract Introduction In a prior Phase 1 trial we showed that an intranasal (IN) recombinant hemagglutinin (HA) H5 vaccine (rH5; A/Indo/05) nanoemulsion-adjuvanted (rH5 NE) and given on days 1 and 29 effectively primed the immune system. Participants received rH5 NE (25—100 µg; IN; n = 24), unadjuvanted rH5 (100 µg; IN; n = 7), or placebo (n = 6). Only rH5 NE recipients exhibited significant increases in HAI titers after a heterologous intramuscular (IM) H5N1 booster on day 197, confirming successful mucosal priming. Anti-H5 antibody-dependent cell cytotoxicity (ADCC) activity also demonstrated this priming effect. Here, we evaluated whether rH5 NE elicited cross reactive ADCC and antibody-dependent cell phagocytosis (ADCP) responses to diverse H5 HAs and examined contributions of HA head and stalk domains. Methods Plasma from days 1, 57, and 225 was analyzed. ADCC was assessed using beads coated with whole, head only, or stalk only H5 HAs incubated with plasma and exposed to a CD16a expressing reporter cell line. ADCP was quantified by THP 1 uptake of antigen-coated AF488—beads. ADCC seroconversion was defined as a ≥ 4 fold increase; ADCP seroconversion as a ≥ 2 fold increase. Results By day 57, 33% (8/24) rH5 NE recipients showed ADCC seroconversion to A/Indo/05 whole HA, rising to 50% after the day-197 IM boost. Unadjuvanted rH5 and placebos seroconverted only after boosting (4/7=57% & 4/6=67%, respectively). Similar trends were seen for A/Viet/04 and A/cow Tx/24. Head specific ADCC seroconversion in rH5 NE reached 46% (11/24) at day 57 and 88% (21/24) at day 225, whereas unadjuvanted rH5 responded only at day 225 (4/7=57%). Placebos showed no responses. Stalk specific ADCC was largely preexisting across all groups, with minimal vaccine induced increases. ADCP trends mirrored ADCC findings. Conclusion Intranasal rH5 NE induces cross reactive ADCC and ADCP responses driven primarily by antibodies targeting the H5-head, supporting its capacity to induce effective mucosal priming. Funding Source Support from the following Grants: NIH U01AI148081, BlueWillow Contract, lead author is a UMB-ITP-Vax scholar (NIH R25AI175011), Topic Categories Vaccines and Immunotherapy (VAC)

Manufacturing CAR-T Cells in a Closed-System, End-to-End Manufacturing Workflow Enhances CAR-T Cell Function 2303378

Abstract Introduction The Tumor Microenvironment (TME)–characterized by hypoxia and altered biophysical stress–is a primary driver of resistance in Chimeric Antigen Receptor (CAR) T cell therapy. Current manufacturing protocols fail to prepare CAR-T cells for hostile in vivo environments, leading to reduced potency and decreased persistence against cancer cells. This study presents a novel, closed-system, end-to-end CAR-T manufacturing workflow that incorporates automated liquid handling and cell harvest capabilities to reduce manufacturing time, complexity and cost. The core innovation lies in the platform’s ability to accurately model key TME stressors through advanced environmental controls, including sustained hypoxia and hyperbaric pressure to produce highly resilient therapeutic T cells. Methods The manufacturing process is fully automated and contained within a single, modular consumable, providing a high-throughput and robust workflow designed to operate in GMP environments. Key steps–including media changes, transduction, and cell harvesting–are performed without operator intervention. Results Expanding anti-CD19 CAR-T cells under hypoxia (5-10% O2) and hyperbaric pressure (5 PSI), conditions analogous to the bone marrow niche, significantly enhanced their potency and persistence. Following tumor target engagement, these cells demonstrated a 3- to 5-fold improvement in efficacy and persistence compared to CAR-T cells cultured under standard conditions (21% O2). In vitro data confirm improved function and increased resistance to TME-like stress. This enhanced therapeutic profile correlates with the enrichment of a stem-like memory T cell (Tscm) subpopulation (characterized by CD45RA+, CD62L+, CCR7+, and CD95+) and the upregulation of the metabolic regulator GLUT1, facilitating metabolic adaptation to the low-oxygen environment. Conclusion This workflow validates the AVATAR Foundry system as a robust, standardized platform for commercial-scale production of complex, physiologically relevant cell therapies. Funding Source n/a Topic Categories Technological Innovations in Immunology (TECH)

Development of novel mouse models to study Clec10a/Mgl2 dynamics in the setting of Mycobacterium tuberculosis infection 2258778

Abstract Introduction Macrophage galactose-type lectin (MGL) is an important modulator of inflammation in various disease settings. While humans possess a single MGL molecule (hMGL/CLEC10A), mice have two homologs of the receptor (mMGL1/Clec10a and mMGL2/Mgl2) that may have overlapping functions with hMGL. We have previously demonstrated that mMGL1 plays an important role in the immune response to Mycobacterium tuberculosis (Mtb) infection by limiting inflammation and augmenting antibacterial activity of macrophages. In contrast, the effects of mMGL2 or mMGL1/2 deficiency have yet to be investigated due to the lack of available knockout mouse models. Methods To address this gap, we generated novel mouse lines that lack mMGL2 alone or in combination with mMGL1 via CRISPR-Cas9 mediated disruption of Mgl2 on the B6.129-Clec10atm1Hed/J background. In vitro assessment was performed in bone marrow derived macrophages (BMDM) from WT, mMGL1 KO, mMGL2 KO, and mMGL1/2 KO mice. Additionally, male and female WT, mMGL2, and mMGL1/2 mice were infected with 400 CFU Mtb via aerosol, and microbiological, immunological, and histological outcomes were assessed 8 weeks post-infection. Results Our in vitro killing assay confirmed that while mMGL1 KO macrophages exhibit significantly higher Mtb burden compared to WT, there was only a modest increase in bacterial burden in mMGL2 KO BMDM and no difference between WT and mMGL1/2 BMDM. In contrast, our preliminary in vivo study showed no difference in lung bacterial burden between WT and mMGL2 KO and significantly reduced bacterial burden in mMGL1/2 KO mice. Interestingly, assessment of lung cytokine levels revealed that mMGL2 KO mice exhibit more pro-inflammatory cytokine production (e.g., IL-1β) than WT counterparts. In comparison, mMGL1/2 KO mice had generally similar or depressed cytokines compared to WT, consistent with microbiological outcomes. Conclusion These results highlight the functional divergence of mMGL1 and mMGL2 in the murine immune response to Mtb. Funding Source NIH/NHLBI R01HL181469 Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

Lactoferrin Supplementation Improves Neonatal Phagocyte Function in a Murine Model of E. coli Sepsis 2261096

Abstract Introduction E.coli K1 is a neonatal specific pathogen with extremely high mortality rates. We hypothesize this mortality is a result of the decreased phagocytic capacity of neonatal immune cells in combination with decreased barrier function due to their open gut barrier. Lactoferrin(LF) is an immune modulator present in all breastmilk. Importantly, it has also been shown to increase support intestinal barrier function. . Utilizing our murine model, we seek to determine the efficacy of LF supplementation on influencing sepsis-associated outcomes. Methods Neonates were enterally gavaged with 0.3mg/g body weight LF or PBS control daily from P0 to P4/5. Sepsis was induced by oral gavage or IP injection of E.coli K1 on P4/5. Results LF significantly decreased sepsis-associated morbidity(p < 0.0001) and mortality(p<.01). LF decreased intestinal permeability (p < 0.0001) and subsequent E.coli translocation into the IP cavity(p=.0011), bacteremia severity was equivalent in both groups (p = 0.3). Serum cytokines were also equivalent in both groups. However, significant difference in immune responses were seen. 12 hours post infection(hpi), LF pups have a higher macrophage (p<.001) count in the IP cavity than control pups, with a higher frequency of activated macrophages(p<.01). 12hpi, LF pups trend towards an increased neutrophil count in the IP cavity(p=.06) and have a significant increase in the frequency of activated neutrophils(p=.05). At 18 hpi, LF and control pups have broadly equivalent frequencies of activated neutrophils, but LF pups have a higher proportion of TLR2+ neutrophils (p=.05) within their activated population. Further immune phenotyping of the IP cavity and spleen/systemic response are underway. Conclusion LF increases phagocyte activation without a cytokine storm, tempering morbidity and ultimately decreasing mortality following E.coli K1 sepsis. Funding Source 1R01AI150687-01 Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

Crystal Domain Engineering of Ni‐based Co‐Free Layered Cathodes for High‐Performance Li‐Ion Batteries

ABSTRACT Ni‐based layered oxides (NCMs) are one of the crucial candidates for high‐energy Li‐ion batteries, but suffer from severe structural degradation owing to diverse irreversible phase transitions, especially when Co is removed. Addressing such intrinsic instabilities calls for creative bulk design strategies, wherein crystal domain engineering emerges as a compelling approach. In this research, we developed a simple one‐step strategy based on crystal domain engineering to controllably integrate locally ordered Li‐rich Li 2 TMO 3 crystal domain, which is composed of LiNi 6‐ x Mn x hexatomic‐ring, into the NMs bulk lattice. By precisely controlling the lithium stoichiometry to obtain “twin domain” Ni‐based cobalt‐free lithium‐rich layered oxides (Ni‐LLOs) with a tunable lithium‐rich functional unit. Benefiting from such crystal domain engineering, the optimal cathode material with competitive capacity (∼200 mAh g −1 ) can deliver an excellent capacity retention of 90.59% after 600 cycles in pouch‐type cells at 1 C. Further mechanistic investigation reveals that the intergrown Li 2 TMO 3 crystal domain suppress the formation of H3 phase and mitigate lattice contraction through a pinning effect, while simultaneously alleviating Li/Ni cation mixing, thereby reducing the necessity for cobalt incorporation. Collectively, this work establishes crystal domain engineering as a versatile and powerful strategy for developing high‐energy, long‐lifespan cathode materials for next‐generation high‐performance lithium‐ion batteries.

Prevalence and impact of bopyrid isopod infestation on mud shrimp populations in the eastern Yellow Sea

Abstract The prevalence and effects of Gyge ovalis (Shiino, 1939) infestation on its host, Upogebia major (De Haan, 1841), were monitored monthly between 2012 and 2015 at two tidal flats in Seonjaedo and Jugyo on the west coast of Korea, eastern Yellow Sea. Gyge ovalis was the predominant parasite on mud shrimp, accounting for over 90% of macroparasite occurrences at both sites. The mean prevalence was 5.0% in Seonjaedo and 29.1% in Jugyo. Monthly prevalence declined over the study period but peaked in summer due to a reduced catch of uninfested mud shrimp. Ovigerous G. ovalis were present from April to September. Infestation of newly settled mud shrimp, together with the infrequent occurrence of small G. ovalis on large hosts, is consistent with predominant establishment during host recruitment and limited later establishment. The size-specific prevalence did not differ significantly between males and females. Estimated apparent annual mortality was 6.2 and 11.5 percentage points higher in infested mud shrimp at Seonjaedo and Jugyo, respectively. Infested mud shrimp were 7.3–14.2% smaller in size, with older cohorts showing larger relative differences. In particular, infested mud shrimp rarely reached the minimum carapace length required for reproduction (25 mm). Size-adjusted weight loss in infested mud shrimp was 14.8% in Seonjaedo and 8.5% in Jugyo, with no difference between sexes. None of the infested females were ovigerous, suggesting female castration by G. ovalis . In the context of its lifespan, the observed persistence of G. ovalis broadly aligned with the duration of the host cohort, with both rarely detected 5–6 years after host recruitment.

Gli3 Regulates PD-L1 Expression in Macrophages and Alters Maturation and Cytokine Profiles in Plasmacytoid Dendritic Cells 2260198

Abstract Introduction Our lab previously demonstrated that TLR—TRIF—IRF3 signaling induces the transcription factor GLI3, revealing a non-canonical regulatory axis beyond Hedgehog (HH) signaling. However, how GLI3 influences myeloid cell function downstream of innate activation remains unclear. Methods Bone-marrow-derived macrophages (BMDM) and dendritic cells (DC) were generated from wild-type (Gli3fl/fl LysMcre-/-) and myeloid-specific Gli3 knockout (Gli3fl/fl LysMcre+/-, referred to as M-Gli3-/-) mice. Macrophages were in vitro polarized to M2 and analyzed for Cd274 (PD-L1) expression by qPCR and flow cytometry. DC subsets (moDCs, cDC1, cDC2, pDC) were in vitro derived and assessed for lineage differentiation, CD86 expression, and cytokine production. Results M2 macrophages from WT mice showed robust PD-L1 expression, whereas MGli3⁻/⁻ macrophages exhibited markedly reduced PD-L1 transcript and surface expression by flow, independent of HH/SMO signaling, as supplementation with sonic hedgehog (Shh) ligand did not restore PD-L1 levels. GLI3 deletion did not impair DC subset differentiation, indicating normal myeloid development. However, matured pDCs from MGli3⁻/⁻ cultures displayed reduced TNF-α and CD86 expression compared with WT DCs, suggesting a selective role for GLI3 in pDC activation rather than lineage specification. Conclusion Building upon our prior demonstration that TLR-TRIF—IRF3 signaling induces GLI3, these findings reveal that GLI3 functions downstream to regulate macrophage PD-L1 and pDC activation markers, positioning GLI3 as a context-dependent modulator of myeloid immunoregulatory functions independent of canonical Hedgehog signaling. Funding Source n/a Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Vaccine Literacy in a Misinformation Era: Implications for Education and Public Trust 2309409

Abstract Introduction The current 92% kindergartner vaccination coverage, central to disease/death prevention, has decreased from last year, with rising nonmedical exemptions, likely driven by widespread misinformation and myths. Public polling shows some parents trust non-medical influencers over public-health experts. Strengthening immunology literacy across undergraduate, graduate, and clinical education supports critical thinking, evidence-based interpretation, and credible source evaluation. Methods An IRB-approved, anonymous assessment (n = 11,153) across science (SM) and non-science (NSM) majors. Results Results showed that, while SM had more positive and correct vaccine beliefs, like only 37% NSM noted strongly agree to “Vaccine benefits, in general, are larger than their risks”, in contrast (p = 0.05) to 57% SM, but many were not sure. Similar results were obtained from “vaccines cause autism” with 62% of SM strongly disagreeing vs 38% NSM (p = 0.05). The value of vaccine discussions in science classes was evident from inaccuracies, like “Mercury is a component in childhood vaccines” where more SM than NSM disagreed (mercury-based thimerosal was removed from childhood vaccines in 1998), indicating the effectiveness of teaching vaccine literacy in a misinformation era. Overall data revealed that even SM could benefit from more formal discussion of myths and misinformation, as only 50.5% of SM agreed with “You do not think that you can get the flu from the flu vaccine” (vs 31.8% NSM, p = 0,05). Conclusion Strengthening immunology training equips learners to evaluate scientific evidence, identify credible sources, and counter vaccine misinformation. Persistent gaps among both science and non-science majors highlight the need for more explicit instruction in debunking myths. Vaccine literacy education that emphasizes critical source evaluation, evidence-based reasoning, and applied strategies such as role-playing is essential to sustaining vaccine confidence and public trust. Funding Source n/a Topic Categories Vaccines and Immunotherapy (VAC)