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Enriching Magneto‐Optical Functionalities in Iron Garnet Films via Compensation‐Driven Magnetic Tuning
ABSTRACT Magneto‐optical functional devices based on iron garnet films are important for optical communication and integrated photonics, where Faraday rotation magnitude, sign, and spectral response can be tuned on demand. However, most reported compensation‐related magneto‐optical responses have been demonstrated in isolated compositions or different formulations, leaving it unclear how a single compositional variable can design compensation temperature, magnetic reversal, and telecommunication‐wavelength Faraday response in a Bi‐rich rare‐earth garnet film. Here, a Bi‐Eu‐Ho‐Ga iron garnet thin‐film platform is established, in which magnetic compensation is systematically tuned through Ga‐mediated Fe‐sublattice dilution. By adjusting Ga content, compensation temperatures of 77, 187 K, 29, and 431 K are achieved in the same materials family. Consequently, distinct Faraday responses are realized at 300 K, including changes in rotation magnitude, sign, and spectra, where large Faraday rotation (−0.081 deg µm −1 ) is achieved under a low saturation field (≈527 Oe), and a self‐biased state with full zero‐field rotation retention and a large reverse nucleation field (≈350 Oe) is realized. Temperature‐dependent Faraday spectroscopy reveals systematic evolution of the magneto‐optical transition energy associated with the compensation state. This work provides a composition‐guided route to compensation‐regulated Faraday responses in Bi‐rich Eu/Ho co‐substituted iron garnet films for telecommunication‐wavelength components.
Facile Induction of Immune Tolerance by an Interleukin-2-TGF-β Surrogate Agonist 2329867
Abstract Introduction CD4+ regulatory T (Treg) cells are essential for immune tolerance. Peripherally induced Tregs (pTregs) complement thymic Tregs by broadening Treg reactivity in response to a changing antigenic landscape. Although both TGF-β and Interleukin-2 (IL-2) synergistically promote functional pTreg development in vitro, their combined roles in inducing pTreg generation in vivo are yet to be exploited for tolerizing immunotherapy. Methods We designed an IL-2-TGF-β “surrogate” co-agonist by creating a single-chain fusion protein between IL-2 and a low-affinity TGF-β mimic agonist derived from a Helminth parasite. This IL-2-TGF-β surrogate functions as an AND-gated co-agonist and enabled simultaneous cis-activation of both IL-2-STAT5 and TGF-β-SMAD2/3 signaling specifically in IL-2 receptor-expressing T cells. Results The IL-2-TGF-β surrogate agonist robustly induced antigen-specific, functional, and stable pTregs in vivo within peripheral lymphoid organs in OVA- or MOG35-55-immunized mice. The induced pTregs display an effector-like, actively expanding state with high Rorγt expression, enabling efficient migration and suppression of intestinal inflammation. Conclusion Treatment with this agonist effectively quelled immune activation in mouse models of allergen-induced allergic inflammation and self-antigen-driven autoimmune neuroinflammation, portending a strategy for the induction of antigen-specific pTregs in vivo to establish immune tolerance in inflammatory, allergic, and autoimmune diseases. Funding Source n/a Topic Categories Lymphocyte Differentiation and Peripheral Maintenance (LYM)
B Cells Reside in the Healthy Murine Retina and are Altered by Lack of IgM 2245387
Abstract Introduction The retina, the central nervous tissue responsible for vision, undergoes functional decline with aging contributing to onset of many diseases. Preserving vision requires a better understanding of how retinal homeostasis is maintained. While the retina has historically been considered immune privileged, recent evidence indicates that ocular tolerance arises from strong, active immune regulation rather than immune system absence. Building on our prior findings that secreted IgM is required for proper retinal homeostasis through aging, we investigated whether retinal B cells contribute to this regulation. Methods Using uS-/- mice (no secreted IgM) and their wild-type counterparts, we collected lymphocytes from retinal extracts separating the vasculated choroid/sclera from the neural and non-neural retina. B cells were analyzed for phenotype by multiparameter flow cytometry, response to LPS in culture, and repertoire by single cell V(D)J sequencing. Results Phenotyping revealed a distinct B cell population that resided primarily in the retinal pigment epithelium layer (RPE), not the choroid/sclera or the neural retina. To our knowledge, this represents the first evidence of resident B cells in the healthy retina. In uS-/- mice a higher percent of these cells displayed CD80, indicating a larger proportion of activated cells than those found in the WT mice. Sorted CD19+ B cells from the RPE responded to LPS stimulation in vitro, demonstrating functional antibody production; while WT CD19+ cells preferentially secreted IgM, us-/- CD19+ cells produced IgG. Single cell sequencing data showed that the CD19+ RPE B cell repertoire shifts with both age and secreted IgM deficiency. Conclusion Together, these results identify a novel population of resident B cells in the RPE and demonstrate that secreted IgM regulates their activation state and repertoire. This work reveals an unrecognized role for B cells in retinal homeostasis and provides new insight into immune regulation within the central nervous system. Funding Source NIH NIAID F32AI174673-01A1 Topic Categories Neuroimmunology (NEUR)
Molecular Insights into the RELT—FLNA Interaction and its Role in Breast Cancer Cells 2259610
Abstract Introduction Receptor Expressed in Lymphoid Tissues (RELT), member of the Tumor Necrosis Factor Receptor Superfamily, is upregulated in breast cancer (BC). A proteomic screen identified Filamin A (FLNA), an actin-binding scaffold protein involved in many cell processes, as a potential RELT-interacting partner. This study aimed to reveal the interaction between RELT and FLNA and to characterize its physiological significance. FLNA has an established role in BC, where its expression correlates with tumor grade and stage, and has been shown to bind Breast Cancer Gene 1/2. Methods Co-immunoprecipitation (co-IP) with western blotting was performed to assess interactions between recombinant RELT and FLNA proteins expressed in HEK293 cells. Deletion mutants of RELT were utilized in co-IP assays to identify the FLNA binding site, using a carboxy-terminal fragment of FLNA (C-FLNA) identified in the proteomic screen. Immunofluorescence (IF) microscopy was used to evaluate RELT—FLNA subcellular colocalization. To examine the effect of co-expression, MDA-MB-231 (231) triple-negative BC cells were transiently transfected with differing combinations of plasmids for RELT, C-FLNA and empty vector control, and analyzed for apoptosis via Annexin V/Propidium Iodide (AV/PI) flow cytometry and X-gal morphology assays. Results Co-IP experiments demonstrated that C-FLNA binds within amino acids 340—400 of RELT’s intracellular domain. IF confirmed cytosolic colocalization of RELT and FLNA, supporting a direct interaction. Co-expression of RELT and C-FLNA induced significantly higher AV/PI staining in 231 cells compared to cells expressing either protein alone, corroborated by X-gal assays. Conclusion These results define a binding region on RELT for C-FLNA and show that co-expression of RELT and C-FLNA enhances apoptosis in BC cells, suggesting a synergistic effect. Ongoing studies are probing whether RELT mutant expression influences BC cell migration, given FLNA’s established role in cytoskeletal dynamics and motility. Funding Source Seed Grant-California Northstate University Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)
Microbiota-dependent IGF-1 limits alveolar macrophage inflammatory function 2257596
Abstract Introduction The impact of the systemic commensal microbiome on the lung microenvironment and alveolar macrophage (AM) polarization is largely unexplored. We find that AMs from mice lacking commensal microbiota (germ-fee) have heightened inflammatory function and that this is coincident with a reduction in IGF-1 protein in the germ-free lungs. The IGF-1 receptor gene (Igf1r) is highly expressed in alveolar epithelial cells (AECs), which are critical for mediating AM anti-inflammatory programming. Methods To define how microbe-dependent IGF-1 shapes AM function, we generated two lines of conditional knockout mice that are Igf1rfl/fl, and with either LysMCre for the conditional deletion in myeloid cells, or Nkx2.1Cre for the conditional deletion in AECs. For both steady-state and after LPS stimulation, AMs from these mice were phenotypically evaluated by flow cytometry and assessed for functional capability such as cytokine secretion and phagocytosis. We also performed RNAseq analysis of AMs isolated from Igf1r deficient mice and germ-free mice. Results We find that IGF1R deficiency in AECs largely recapitulates AM phenotypes overserved in germ-free mice, with increased phagocytic capacity and enhanced inflammatory cytokine production in response to microbial stimuli. RNAseq analysis of germ-free AMs revealed 1639 differentially expressed genes, and protein interaction networks allowed us to identify a microbiota-dependent subnetwork of transcription factors including CEBPβ, PU.1, and Smad3. We are analyzing RNAseq from Igf1r deficient mice to identify AM programs regulated by IGF-1-dependent transcription factors. Conclusion Next steps include spatial transcriptomics analysis of lungs from conditional Igf1r knockout mice to interrogate IGF-1 dependent AM-AEC crosstalk via ligand-receptor analysis and gene regulatory networks. This work will determine how microbiota-dependent IGF-1 stabilizes cell-cell communication to support lung homeostasis and regulate inflammation. Funding Source n/a Topic Categories Mucosal and Regional Immunology (MUC)
Evaluating the Immune Response to the Artificial Oxygen Carrier OxyVita® 2308574
Abstract Introduction A major challenge in treating uncontrolled blood loss through hemorrhage is the lack of an oxygen delivery system to support vital organs when whole blood is unavailable. OxyVita is a polymerized stroma-free bovine hemoglobin-based oxygen carrier (HBOC) that was developed by OXYVITA Inc. to deliver oxygen in emergency medical situations. The current study examines the immunological consequences of exposure to OxyVita both in mice and in cell culture. Methods We immunized BALB/c mice with OxyVita or saline either in the peritoneal cavity (IP) or in the tail vein (IV) two to three times. Collected blood sera were evaluated for the presence of antibodies reactive to the OxyVita polymer by ELISA. We further evaluated the ability of OxyVita to stimulate the RAW 264.7 macrophage cell line to secrete various cytokines in vitro by ELISA. Results OxyVita immunization stimulated high concentrations of circulating antibodies in mice after a single exposure via both the IP and IV routes. These concentrations increased with subsequent exposures demonstrating immunological memory responses. Importantly, the mice appeared to remain in good health throughout the experiment and immunized and non-immunized animals gained weight at similar rates. OxyVita stimulated RAW 264.7 cells to secrete the inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) as well as the anti-inflammatory cytokine interleukin-10. Conclusion These results suggest that the OxyVita polymer has the potential to stimulate both the innate and adaptive immune responses in vivo and in vitro, however, there may be a balance struck between the pro- and anti-inflammatory signals elicited. The lack of obvious pathology in mice following multiple exposures provides encouraging support for continued preclinical studies with this novel HBOC. Funding Source College departmental research budget less than $1000 per year Topic Categories Translational and Interventional Immunology (TI)
Influenza-specific lung-resident memory B cells assist CD4 recall responses during challenge infections 2256984
Abstract Introduction In repeated influenza A virus (IAV) infections, lung-resident memory B cells (BRMs) enhance early recall responses. However, in heterosubtypic infections, antibodies produced by lung BRMs do not neutralize the challenge virus’s surface glycoproteins, suggesting multifaceted functions of BRMs beyond antibody secretion. Methods Single-cell RNA sequencing of CD45+ lung cells after primary IAV/PR8 infection and subsequent IAV/X31 challenge revealed significant changes in B and T cell populations between B cell-specific STAT1 knockouts and C57BL/6 mice. B-STAT1 KOs failed to generate BRMs and exhibited a marked reduction in antibody secreting cells (ASCs), confirmed by ELISPOT assays showing decreased flu-specific IgA and IgG ASCs post-challenge. Flow cytometry analysis further showed decreased CD4+PD1hiCD11a+ and CD4+IFNγ effectors in the lung. Results Functionally, B-STAT1 KOs were more susceptible to reinfection, with reduced viral clearance compared to wildtypes. Importantly, antibody deficiency did not account for these observations, as antibody-deficient AID−/−α¼s−/− mice and B cell-specific BLIMP1 knockout mice, which still generated BRMs but produced minimal flu-specific antibodies, showed intact or enhanced CD4 T cell recall responses. To understand the mechanisms involved, we used B cell-specific MHCII inducible knockout mice and observed that deletion of MHCII in BRMs before challenge led to higher peak viral titers and fewer lung CD4+PD1hiCD11a+ effectors, along with abrogated secondary germinal centers and decreased flu-specific ASCs. Additionally, intranasal immunization with flu-specific B cell tetramers in wildtype mice showed that BRMs rapidly captured antigen in vivo, in contrast to their lymphoid counterparts. Conclusion Collectively, these findings emphasize that local interactions between BRMs and effector CD4 T cells are vital for effective antiviral responses in the lung, with BRMs supporting CD4 T cell functions, especially at low antigen doses through antigen presentation. Funding Source NIH 1R01AI153413-01 Topic Categories Mucosal and Regional Immunology (MUC)
Single-cell RNA sequencing reveals conserved T cell populations across kidney tissue and urine of patients with immune checkpoint inhibitor nephritis 2262974
Abstract Introduction Immune checkpoint inhibitors inhibit the negative regulation of T cells, leading to both anti-tumor activity and immune-related adverse events such as acute interstitial nephritis (ICI-AIN). The immunologic drivers of ICI-AIN are unknown. We hypothesized that both resident and circulating CD8+ T cell subsets are present in ICI-AIN and that they are conserved across kidney tissue and the urine sediment. Methods To characterize the cellular populations that are enriched in ICI-AIN, we used scRNAseq to analyze epithelial and immune cells in kidney tissue and urine from a cohort of 25 patients with biopsy-proven or clinically-adjudicated ICI-AIN, 12 ICI-treated controls with non-AIN AKI, 12 ICI-treated controls with stable kidney function, and 12 ICI-naive patients with stable kidney function prior to ICI initiation. A total of ∼250,000 cells were analyzed and revealed 24 transcriptionally distinct cell subsets, including CD8+ and CD4+ T cells, NK cells, B cells, myeloid cells, renal tubular epithelial cells, and urogenital epithelial cells. Results A range of T cell subsets was identified, existing on a phenotypic spectrum spanning circulation (KLF2) to residency (ITGAE), and cytotoxicity (IFNG, GZMK) to exhaustion (TIGIT). These cell subsets were conserved across both kidney tissue and urine. Gene expression analysis in ICI-AIN samples revealed populations of CD8+ T cells expressing CXCR3 and myeloid cells expressing the interferon-y-stimulated ligands CXCL9/10, suggesting potential cell-cell interactions. Conclusion Taken together, our data contribute to improved understanding of the cellular perturbations in ICI-AIN and reinforce a role for the IFN-y pathway in driving ICI-AIN. The conservation of T cell types observed across kidney tissue and urine suggests the potential for development of a non-invasive urine-based diagnostic test for ICI-AIN. Funding Source American Kidney Fund Clinical Scientist in Nephrology Award; NIH/NIDDK Topic Categories Immune Mechanisms of Human Disease (HUM)
The Immunological Landscape of Biliary Atresia: Focus on Th2 and Th17 Profiles 2330296
Abstract Introduction Our understanding of the underlying causes and immunological mechanisms of biliary atresia remains limited. Hence, the study aimed to investigate the Th2 and Th17 immune profiles and autoimmune features in infants with biliary atresia. Methods A comprehensive analysis of immune markers, T and B cell subsets, cytokines, gene expressions, autoantibodies, and serum immunoglobulin levels was conducted in a prospective case-control study, correlating the results with liver histology and immunohistochemistry. Results A heightened surface expression of costimulatory molecules (CD40/CD40L and ICOS), increased plasma B cell percentages, and raised IgA and IgG levels were observed. Plasma cytokines, i.e., IL-2, IL-4, IL-6, IL-10, IL-17, TNF, and IFNγ, were significantly elevated with four-fold higher expression of RORγt compared to FOXP3 in all patients. Liver histology displayed characteristic features of BA with dense lymphoplasmacytic infiltrate comprising CD3+ T and CD20+ B cells around portal tracts and weak positivity for autoantigens and autoantibodies. Conclusion The presence of Th1/Th2 imbalance and Th17 immune response, characterised by an imbalance in proinflammatory gene expression, heightened secretion of cytokines, overactivation, and expansion of lymphocytes, along with the detection of autoantibodies, collectively point to immune-mediated mechanisms playing a notable role in the progression of biliary atresia. Funding Source ICMR, India Topic Categories Immune Mechanisms of Human Disease (HUM)
Germline-encoded recognition underlies development of convergent antibodies in humans 2246040
Abstract Introduction The presence of food-specific IgG in response to dietary ingestion has been long-observed. In a subset of individuals, food-specific IgG can class-switch to IgE, potentially causing anaphylaxis. We and others have previously identified highly homologous, or public, peanut-specific antibodies in allergic individuals. We hypothesized that we can use the similar, stereotyped pathways of convergent antibodies to peanut to construct germline-encoded structural models of antibody convergence. Methods Using a set of epitope-specific antibodies to peanut cloned from peanut-allergic patients, we probed antibody-antigen interactions using mutagenesis, biolayer interferometry and molecular modeling. Results Using this set of convergent antibodies with distinct antibody gene rearrangements and similar complementary determining regions (CDRs), we identified had identical epitope-paratope interactions and highly similar energetics in structural models. Peanut specificity of these antibodies is germline-encoded across commonly used gene rearrangements, occurs irrespective of allelic heterogeneity, and has significant junctional malleability. Using molecular modeling, we identified the paratope residues critical for these convergent binding interactions and probed the entire human antibody repertoire to understand the genetic constraints on this stereotyped recognition of a public epitope on a dominant allergen. Conclusion We can utilize molecularly defined germline-encoded recognition of peanut allergen to better understand how the human antibody genome predisposing humans to recognizing peanut proteins. Funding Source n/a Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)
Distinct Innate Immune Correlations to Tissue-Resident Memory T Cell Distribution across the Female Reproductive Tract 2259843
Abstract Introduction Tissue resident memory T cells (TRM) positioned within immune-restricted tissue sites, including the female reproductive tract (FRT), are essential contributors to immunity against invading pathogens. Although tissue environments provide homeostatic supports required for TRM maintenance, the mechanisms that regulate immune memory surveillance in distinct regions of the FRT are unclear. Methods Here, we compared cellular and transcriptomic profiles from the different FRT anatomic regions using hysterectomy hemi specimens from healthy donors of reproductive age and known hormonal status. Results We found that the TRM populations exhibited region-specific differences in abundance and phenotype, with overall greater heterogeneities identified in uterine tissue. Correlations between innate cell subsets and TRM properties across FRT compartments were identified with NK cell subtypes and migratory memory T cells, which indicated an association of these populations with endogenous levels of the sex hormone, progesterone. Single-cell RNA sequencing revealed regional changes in TRM transcriptional programming associated with T cell functionality and plasticity. Ex vivo treatment of FRT epithelial cell populations with IFNg showed disparities in response kinetics associated with T cell activation. Conclusion Taken together, this study describes compartmental differences in innate cell contributions to TRM programming that are influenced by sex hormone status. We further identify correlations between distal tissue sites in the FRT that might inform upon uterine health. Funding Source NIH R21AI180610 Topic Categories Mucosal and Regional Immunology (MUC)
Defects in CD8+ T cell suppression by Foxp3-dE2 regulatory T cells 2257749
Abstract Introduction Regulatory T-cells (Tregs) prevent autoimmunity through suppressive functions which are largely programmed by the transcription factor FOXP3. Healthy humans express two major alternatively spliced isoforms of FOXP3: One full-length version containing all coding exons (FOXP3-FL) and one version lacking the second exon (FOXP3-α”E2). Although healthy humans have Tregs programmed by either or both isoforms, humans with sole FOXP3-α”E2 expression develop lethal autoimmunity. The overall goal of this study is to identify the defects in suppression by FOXP3-α”E2 Tregs. Methods This study used novel mouse models including Foxp3-α”E2 mice, influenza A viral infection, RNA-seq, ATAC-seq, spectral flow cytometry, confocal microscopy, and standard molecular biology techniques. Results Foxp3-α”E2 Tregs have reduced expression of core Treg signature genes, including CD25 and IL-2/STAT5 signaling targets. Reduced CD25 expression on Foxp3-α”E2 Tregs leads to lowered pSTAT5 responsiveness to IL-2 stimulation in vitro. Diminished regulation of IL-2 by Foxp3-α”E2 Tregs associates with enhanced CD8+ T-cell expansion, activation, and memory formation in response to influenza viral infection. These defects in T cell restraint are intrinsic to Foxp3-α”E2 Tregs as the phenotype is maintained in a Foxp3-FL-DTR/α”E2 mouse model where WT Tregs are depleted immediately prior to infection. These phenotypic and functional defects in Foxp3-α”E2 Tregs are putatively driven by impaired binding of the Foxp3-α”E2 isoform to Runx1 which is the only transcription factor with enriched promoter binding motifs amongst differentially expressed genes and differentially accessible chromatin. Conclusion Reduced expression of key inhibitory molecules on Foxp3-α”E2 Tregs results in diminished IL-2 regulation and enhanced CD8+ T-cell activation and memory formation. These findings are critical for understanding the defects in suppression by Foxp3-α”E2 Tregs and how these cells may contribute to aberrant immune responses. Funding Source NIAID 1R01AI188364-01 awarded to Steven Ziegler & NSF-GRF DGE-2140004 awarded to Kristin Weinstein Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)
Peripheral memory T cells with self-renewing properties increase with tumor-targeting IL-12 immunocytokine therapy 2308731
Abstract Introduction Stem-like memory T cells (TSCM) are a rare subset of multipotent, self-renewing cells important for antitumor control. Accumulation in the tumor or tumor-draining lymph node of TSCM or T cells expressing TCF1, critical in self-renewal, are associated with improved response of patients to immune checkpoint blockade. These tissues, however, are often not available for study. Here, we evaluated the effects of a tumor-targeting IL-12 immunocytokine PDS01ADC (previously termed NHS-IL12), with promising activity in preclinical and clinical studies, on peripheral T cell stemness in murine hosts and cancer patients. Methods Prevalence of TSCM and expression of the murine T cell stemness marker SCA1 were evaluated by flow cytometry in spleens of mice treated with PDS01ADC. Similarly, TSCM and TCF1+ T cells were assessed in peripheral blood of 28 patients with advanced solid tumors treated with PDS01ADC (NCT01417546). Results PDS01ADC treatment in mice increased peripheral CD8+ and CD4+ TSCM and effector memory T cells (TEM) expressing SCA1. In patients, treatment with PDS01ADC increased CD8+ and CD4+ TSCM and TEM in the periphery expressing TCF1, with increased TCF1+ T cells associated with disease control. Most peripheral TSCM were negative for PD-1 and TIGIT throughout treatment, indicating their continued quiescence and self-renewal. Additionally, expanded TCF1- CD8+ TEM expressing PD-1 and/or TIGIT showed increased intensity of granzyme B, indicating that treatment did not induce CD8+ T effector cell dysfunction. Conclusion This is the first report of a cytokine-based therapy increasing peripheral T cell stemness in mice and humans. Increases in peripheral T cell stemness induced by PDS01ADC correlated with disease stabilization and may serve as an indicator of which patients are more likely to benefit from therapy. These data support future studies combining PDS01ADC with other agents to synergize with this increase in T cell stemness. Funding Source NIH/NCI Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)
Development and Therapeutic Evaluation of a Uniform Lymph Node Cell Transfer Model of Alopecia Areata 2256823
Abstract Introduction Alopecia areata (AA) is an autoimmune disease characterized by non-scarring hair loss, primarily mediated by cytotoxic T-cell attack on hair follicles. To establish a reproducible and uniform preclinical model for therapeutic evaluation, we developed a lymph node cell (LNC) transfer - induced AA mouse model on the C3H background. Methods LNCs from aged C3H mice with spontaneous AA were isolated, activated, expanded in vitro, and injected intradermally into young healthy C3H mice. To evaluate the translational utility of this model, mice with established AA (>15 weeks) were treated with either oral Ritlecitinib or topical Tacrolimus for 10 weeks. Results Within 5 weeks, recipient mice developed progressive ventral hair loss, and by 15 weeks, nearly 90% exhibited severe AA with clinical scores above 5, including complete abdominal and >75% dorsal alopecia. Flow cytometry revealed elevated CD3+ T cells, CD8+ T cells, and NKG2D+ cells in both skin and lymph nodes. Immunohistochemistry and RNA analysis confirmed MHCI upregulation and NKG2D+/CD8+ T cell involvement, validating the model’s autoimmune AA phenotype. Ritlecitinib or Tacrolimus treatments significantly improved AA symptoms, with Tacrolimus group achieving near-complete hair regrowth (∼100%) and resolution of alopecia. Treatment reduced MHC-I expression and decreased CD8+ T cell infiltration in the skin, as confirmed by flow cytometry and IHC. Conclusion The LNC transfer—induced AA model provides a robust and uniform preclinical platform that recapitulates the autoimmune pathogenesis of AA and enables the evaluation of therapeutic candidates for alopecia areata. Funding Source n/a Topic Categories Therapeutic Approaches to Autoimmunity (THER)
T-Cell Synaptosomes Orchestrate Long-Term Anti-Tumor Immunity via Proliferative and Metabolic Reprogramming 2266860
Abstract Introduction T-cell activation requires intimate contact with antigen-presenting cells (APCs), during which activated T cells deposit microvesicles termed T-cell immunological synaptosomes (TIS) onto APCs. Although TIS can activate APCs, their broader in vivo roles are largely unknown. We asked whether antigen-independent, systemic delivery of TIS could durably reprogram innate compartments and elicit antitumor immunity. Methods TIS were harvested ex vivo from activated T cells and administered intraperitoneally to mice. Cellular uptake, persistence, and time-course changes in immune cell composition were assessed by flow cytometry. Functional reprogramming was profiled by transcriptomic analysis and by cytokine and chemokine quantification, using LPS as a control. Antitumor efficacy was evaluated in the MC38 colon cancer model and by tumor rechallenge. Results Here, we show that TIS are primarily phagocytosed by macrophages and dendritic cells, persist intracellularly for several days, and reprogram these cells in a manner distinct from LPS. TIS upregulate genes involved in metabolism, proliferation, and anti-inflammatory responses, and promote immune cell recruitment, including eosinophils. Notably, TIS induce minimal immune activation upon initial exposure but trigger a rapid and robust response upon secondary administration, indicating a priming effect reminiscent of adaptive immunity.In an MC38 colon cancer model, TIS treatment resulted in near-complete tumor suppression and durable protection upon rechallenge. Conclusion Systemically delivered TIS act as adhesion derived vesicular effectors that durably reprogram immunity, inducing trained immunity like priming and bridging adaptive and innate arms. These properties position TIS as a potent, long-lasting, vesicle-based platform for cancer immunotherapy. Funding Source n/a Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)
Reprogrammable Bistable Metasurface for Arbitrary Electromagnetic Wave Manipulation
ABSTRACT Mechanically reconfigurable metasurfaces have been designed to achieve continuous modulation of electromagnetic responses through the integration of deformable elements with structurally simple architectures. Although current implementations with independently addressable deformable units enable multifunctionality, their constrained phase modulation range imposes fundamental limitations on achieving fully reprogrammable metasurfaces. Here, we report for the first time a 1‐bit phase‐coding concept of a deformable unit based on the controllable interference of two three‐dimensional (3D) bistable antennas, while maintaining superior broadband performance. By employing a hollow hyper‐elastic substrate, we create a reliable platform for 3D buckling and shape switching of antennas, where out‐of‐plane loadings applied to each unit allow programming of the desired phase patterns. A reprogrammable metasurface prototype is meticulously designed and fabricated, demonstrating reliable, repeatable, and arbitrary functionality‐switching capabilities. This concept establishes a robust foundation for mechanically reprogrammable metasurfaces and opens broader possibilities for applications in adaptive imaging, mechanical sensing, cloaking, information processing, and beyond.
SPIC-dependent erythrophagocytic macrophages promote bacterial tissue persistence during Salmonella infection 2309292
Abstract Introduction Macrophages maintain tissue homeostasis by phagocytosing spent cells, recycle nutrients, and mounting antimicrobial responses to eliminate pathogens. Yet, they can also act as a cellular niche for intracellular bacteria, such as Salmonella enterica, to persist in infected tissues within granulomas, which are immunological structures comprised of macrophages and other cell types. We seek to define mechanisms controlling bacterial persistence in macrophages and tissues. Methods Fully virulent Salmonella Typhimurium (STm) is used to infect 129x1/SvJ mice, which have intact NRAMP1 function required for efficient macrophage iron recycling and the host’s resistance to intracellular pathogens in humans and mice. ScRNA-seq, flow cytometry, confocal microscopy, and novel knockout mice are employed to define macrophage mechanisms influencing bacterial tissue persistence. Results Comparative scRNA-seq analysis of monocytes and macrophages in infected spleens identifies a functional correlation between bacterial persistence and SPIC, a transcription factor that controls macrophage capacity for recycling spent red blood cells (RBCs), heme, and iron in steady-state and inflamed tissues. STm infection robustly induces SPIC in macrophages and alters tissue iron distribution. SPIC-expressing macrophages have significantly higher CD86, cytokine production, and intracellular RBCs, linking macrophage activation with erythrophagocytosis. Intriguingly, these macrophages are more likely to harbor STm compared to other macrophages. Using novel Spic-/- mice generated with CRISPR editing, we find that Spic deletion reduces macrophage CD86 levels and erythrophagocytic macrophage abundance. Unexpectedly, Spic-/- mice have a defect in granuloma formation and lower tissue bacterial levels, indicating impaired bacterial persistence. Conclusion Our findings suggest that SPIC is essential for macrophage activation and recycling of RBCs, heme, and iron in infected tissues, yet this function promotes pathogen persistence. Funding Source NIAID Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)
Characterization of Anti-influenza B Hemagglutinin Antibodies 2248890
Abstract Introduction Influenza B viruses continue to cause seasonal outbreaks around the world. The mismatch between vaccine and circulating strains was commonly detected in the outbreaks in Taiwan. Co-circulation of both antigenic lineages (Yamagata and Victoria lineages) was frequently found in the outbreaks in Taiwan as well. While antibody immunity plays a major role in the protection against influenza, the information of human antibody response to influenza B virus mainly comes from serological studies. Methods We have detected the induction of antibody-secreting B cell response to influenza B viruses and isolated B cell-derived antibodies from adults status post inactivated influenza vaccination. A panel of human antibodies that react to influenza B hemagglutinin in the binding assays was identified and further characterized in details. Results Each of influenza B antibodies has unique sequence and variable region VDJ rearrangements. Among anti-influenza B hemagglutinin antibodies, a substantial portion showed cross-reactivity with both Yamagata and Victoria lineage hemagglutinins. The majority of lineage-specific and cross-lineage anti-influenza B hemagglutinin antibodies neutralized the corresponding virus in the vaccine. Epitope mapping by selection of escape mutants revealed that neutralizing antibodies recognized the epitopes that surrounds the receptor-binding site. Besides, the influenza B hemagglutinin residue change of circulating strains was tightly related to the loss of neutralization by antibodies, which indicates the occurrence of antigenic change. Conclusion In summary, we dissected the human antibody repertoire against influenza B hemagglutinin induced by vaccination, performed fine epitope mapping of viral hemagglutinin, and demonstrated the role of critical antigenic determinants in the process of antigenic evolution of virus. Funding Source n/a Topic Categories Viral Immunology (VIR)
Mycobacterium tuberculosis inhibits nuclear factor erythroid 2-related factor 2 (NRF2) activity via type 1 interferon production 2259864
Abstract Introduction Mycobacterium tuberculosis (Mtb), the primary causative agent of human Tuberculosis (TB), is the leading cause of infectious death worldwide. Mtb is known to cause a type 1 interferon (T1 IFN) response, which is detrimental to macrophage control of Mtb, evident by increased TB severity or reactivation of latent TB upon viral infection. However, the mechanisms underlying this are poorly understood. Mtb invades macrophages, causing the generation of excess reactive oxygen species (ROS), which can lead to programmed cell death. Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor activated to combat the high levels of ROS by inducing the transcription of antioxidants (AOX). We tested the hypothesis that T1 IFNs impair host resistance to Mtb by suppressing NRF2 and the AOX response. Methods Bone marrow-derived macrophages (BMDMs) from C57BL/6 (WT) and Ifnar1-/- mice were infected with Mtb or stimulated with IFN-β and/or heat killed (HK) Mtb. RNA was collected at 6, 12, and 24 hours for RT-qPCR, and total protein was collected for immunoblotting. Nuclear and cytosolic cell fractions were also collected at 24 hours for immunoblotting to determine transcription factor localization. Results Immunoblotting for NRF2 revealed no significant change in protein levels with IFN-β treatment. Despite this, NRF2-induced AOX genes showed lower mRNA and protein expression when stimulated with IFN-β in WT BMDMs, which was recapitulated in protein expression at 24 hours. In response to Mtb infection, AOX protein levels were significantly elevated in Ifnar1-/- BMDMs compared to WT BMDMs. Furthermore, IFN-β stimulation significantly decreased nuclear localization of NRF2. Conclusion These data indicate that T1 IFN signaling suppresses NRF2 nuclear localization and NRF2-induced AOX responses. These results imply that regulation of T1 IFNs or cellular redox status could be viable options for decreasing TB severity. Funding Source n/a Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)
Targeting a cancer cell Interferon-TBK1 signaling axis attenuates inflammatory memory mediated resistance to immune checkpoint blockade 2257735
Abstract Introduction Acquired resistance in cancer is a major obstacle to durable response after immune checkpoint blockade (ICB). While interferon (IFN) signaling is frequently linked with effective ICB response, prolonged interferon signaling within cancer cells paradoxically drives immune suppression. In preclinical mouse models of ICB, relapsed tumors possess an altered epigenetic landscape characterized by inflammatory memory domain accessibility maintained by STAT1 and IRF3. Here, we restore ICB response by identifying and targeting pathways that maintain IFN-associated memory and resistance. Methods Res 499 tumor cells derived from a late-relapse B16 melanoma were manipulated as indicated, flank-injected into C57BL/6 mice, and treated with ICB. Tumors were harvested on day 16 post-implantation for RNA-seq, ATAC-seq, and flow cytometry. Results Prolonged exposure of cancer cells to IFN selectively increases the expression of a subset of IFNy stimulated genes, or “memory ISGs”, which are enriched for immune evasive properties. Moreover, persistent IFN signaling induces elevated expression of not only dsRNA-forming endogenous retroelements (EREs), but also of IFN-inducing dsRNA sensors such as MDA5, establishing a STAT1 and IRF3 activating feed-forward loop. Consequently, knock out of MDA5, or pharmacological blockade of IFN and MDA5 signaling via JAK1/2 and TBK1 inhibitors respectively, lowers ERE expression, decreases chromatin accessibility at inflammatory memory loci, and increases ICB sensitivity. Via flow cytometry, we observe that ex vivo JAKi and TBK1i treatment, in a cancer cell intrinsic manner, induces a more stem-like CD8 T cell response following ICB, possibly through improved interactions with myeloid cells. Given emerging clinical data supporting JAK inhibition in ICB-refractory tumors, these findings may suggest additional benefits from targeting TBK1 as well. Conclusion Combined JAK and TBK1 inhibition attenuates inflammatory memory associated resistance and enhances ICB efficacy. Funding Source Mark Foundation for Cancer Research Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)