Browse Articles

Regulatory Role of MSMB in Lymphoma and Its Tumor Suppressor Function Across Cancer Types 2258421

Abstract Introduction Lymphoma is a globally prevalent malignancy driven by diverse genetic alterations. Identifying novel genes that influence tumor growth provides critical insight into mechanisms of oncogenesis. The gene MSMB (β-microseminoprotein), a known tumor suppressor in prostate cancer, may have a broader regulatory role in other cancers. This study investigates whether MSMB functions similarly as a tumor suppressor in lymphoma, linking computational predictions with functional validation. Methods RNA-seq data (project PRJNA314605) were analyzed to identify genes differentially expressed in lymphoma. MSMB was found to be strongly downregulated (log₂ fold change ≈ —19.6). To evaluate its functional role, CRISPR-Cas9 knockout was performed in lymphoma cell lines expressing normal MSMB levels. Cell viability was measured using the Trypan Blue exclusion assay and compared to unmodified control cells. Results Computational analysis confirmed significant MSMB downregulation in lymphoma compared with normal tissue. Knockout of MSMB resulted in increased viable cell counts relative to controls, suggesting that loss of MSMB promotes proliferation. These findings parallel the gene’s established tumor-suppressive role in prostate cancer, supporting shared molecular mechanisms across tumor types. Conclusion MSMB appears to act as a tumor suppressor in both prostate cancer and lymphoma. Its downregulation and the enhanced cell viability following knockout support a conserved role in limiting tumor growth. Further mechanistic studies will clarify how MSMB regulates proliferation and assess its potential as a therapeutic target in diverse cancers. Funding Source n/a Topic Categories Translational and Interventional Immunology (TI)

Parasympathetic neural regulation of immune tolerance in corneal allografts via inhibition of dendritic cell activation and T cell polarization 2253341

Abstract Introduction This study aimed to investigate the role of the parasympathetic nervous system in the allorecognition and rejection of murine corneal allografts. Methods We used 8- to 12-week-old male C57BL/6 (B6 and 1Ab) and BALB/C (IAd) murine models of corneal allografts. Following keratoplasty, the graft survival rate and opacity were assessed until 12 weeks with or without the administration of a 0.1 mL scopolamine injection. Transcriptome changes, the presence of infiltrating antigen-presenting cells (APCs) and specific T-cell types were serially determined from the donor corneal button and draining lymph nodes (LNs) until 8 weeks after the keratoplasty procedure. Results Compared to the syngeneic models, the alloimmune models were observed to have significantly distinct gene expression profiles following the keratoplasty. The total number of differentially expressed genes (DEGs; defined as ≥ 2-fold change) in the alloaccepted (Allo-ac) models relative to the syngeneic ones was 1046 (712 upregulated, 334 downregulated), whereas 148 DEGs (136 upregulated, 12 downregulated) were identified when the Allo-ac models were compared to the allo-rejected (Allo-rj) ones. Corneal opacity and rejection rates increased significantly after the scopolamine injection. Although the CD207+ cells were not change, CD11c+ and F4/80+ cell traffic to the draining LNs increased significantly following the scopolamine treatment. Additionally, Foxp3+ Treg generation and enhanced Th1/Th17 polarization in the early stage grafts were found with scopolamine injection. Conclusion Parasympathetic innervation may play a critical role in terms of regulating corneal allograft survival by modulating APC activation, lymph node trafficking, and T-cell infiltration. Funding Source This work was supported by the Advanced Science Research Program (Grant no. RS-2024-00344204) through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science, and Technology, Seoul, Korea Topic Categories Transplantation Immunology (TRAN)

An Intracellular C3-CFB Complement Axis Reprograms Tubular Metabolism and Chromatin to Drive Kidney Fibrosis 2307504

Abstract Introduction Complement is often viewed as liver-derived and extracellular, yet many non-hepatic cells generate intracellular complement. Proximal tubular epithelial cells (TECs) drive kidney injury and fibrosis and express complement, but how de novo TEC complement controls metabolism, chromatin, and fibrogenesis is unknown. We asked whether a TEC-intrinsic complement axis links inflammatory signaling to metabolic and epigenetic reprogramming after injury. Methods Mouse TEC injury models were combined with confocal microscopy, Seahorse metabolic profiling, single-nucleus and bulk RNA-seq, CUT&Tag, MNase-seq, and EMSA. C3 and CFB were perturbed using conditional C3 deletion, cell-permeable CFB inhibitors, and structure-guided CFB mutants informed by AlphaFold2/GraphSite modeling. Human kidney single-cell and bulk transcriptomes were analyzed for conservation and clinical relevance. Results IL-1β—NF-κB/c-JUN induced C3 and CFB in injured TECs. C3 accumulated in mitochondria and co-localized with CFB, which processed C3, rewired metabolism, and promoted profibrotic programs. CFB also accumulated in nuclei; CUT&Tag/EMSA and modeling defined a DNA-binding motif and pocket in CFB. Nuclear CFB cleaved histones, blocked by CFB inhibitors, and MNase-seq showed increased nucleosome protection with CFB inhibition. Conditional C3 deletion or intracellular CFB inhibition reduced TEC metabolism and attenuated post-injury interstitial fibrosis in mice. In human kidney datasets, TEC C3-CFB co-expression associated with injury signatures and inversely correlated with kidney function. Conclusion A TEC-intrinsic C3—CFB complement axis links inflammatory cytokine signaling to mitochondrial metabolism, chromatin state, and fibrosis after kidney injury. Nuclear CFB acts as a DNA-binding protease that modulates histones and nucleosomes. Targeting intracellular, rather than systemic, complement may limit inflammatory kidney disease while preserving host defense. Funding Source NIH Intramural Research Program Apellis Pharmaceuticals Inc, Waltham, MA, United States Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)

Evidence for Human Thymopoiesis in a Porcine Thymus Graft and T Cell Tolerance to the Source Pig in a Human Recipient of a Thymokidney Xenotransplant 2254531

Abstract Introduction Porcine thymic transplantation tolerizes xenogeneic recipients to the porcine source animal in animal models. A 54-year-old woman with complex comorbidities received a composite thymokidney transplant from an GGTA1 knockout pig, achieving initial renal function before xenograft failure for non-immunological reasons on postoperative day (POD) 47. Methods Serial peripheral blood mononuclear cell (PBMC) samples were analyzed by spectral FCM, and mixed lymphocyte reactions (MLRs) were performed on purified T cells to assess tolerance. Thymocytes were isolated from the thymic portion of the xenograft explant and analyzed using spectral FCM Results T cell levels in peripheral blood declined to 10/µL post-induction therapy and recovered to a peak of 342/µL by POD28. By POD21, 53% of the recovering CD4 T cells displayed a CD45RA+CCR7+ “naïve” phenotype and expressed CD31, consistent with recent thymic emigrants (RTEs). Pre-transplant CD4 T cells included 20.8% RTEs (Figure 1A). FCM analysis on cells from the POD47 thymic xenograft revealed human CD45+ leukocytes (0.53%), including double-positive (CD4+CD8+), single-positive, and double-negative thymocytes. The double-negative cells expressed markers such as CD5, CD7, CD1a, and CD34, consistent with human T cell progenitors in the porcine thymus (Figure 1B). MLR results demonstrated progressive hyporesponsiveness toward the source pig with preserved responses to third-party pig and allogeneic human cells, achieving full donor-specific unresponsiveness by POD47 and POD86 (Figure 1C). Conclusion These findings suggest that a porcine thymus in a thymokidney xenograft supported human thymopoiesis and the development of T cells tolerant to the pig. Thymic transplantation is a promising approach to achieving T cell tolerance in xenotransplant recipients Funding Source n/a Topic Categories Transplantation Immunology (TRAN)

Protective Immunity after DNA Vaccination against Pneumonic Plague Using a Needle-Free Jet Injection Platform 2253077

Abstract Introduction Yersinia pestis (Yp), a facultative anaerobic gram-negative bacillus, causes plague, which if untreated has a case-fatality rate approaching 100% in primary pneumonic form. Yp is a known biothreat agent that can be aerosolized to potentially cause pneumonic plague outbreaks, and there is no licensed vaccine. Methods Here we used a pneumonic plague model in which BALB/c mice were exposed to aerosolized Yp strain CO92 to compare DNA vaccines encoding Yp antigens LcrV and F1 with established adjuvanted subunit vaccines based on LcrV and F1 proteins. DNA was delivered using a needle-free PharmaJet Tropis device recently modified for use in small animals, with no additional antigens or adjuvants. Results After two vaccine doses, mice vaccinated with F1 and/or LcrV DNA had cellular immunity comparable to the most effective subunit vaccines, as measured by cytokine secretion and counts of IFN-γ-producing splenocytes after ex vivo restimulation. LcrV DNA vaccination generated high anti-LcrV serum antibody titers, was effective at blocking bacterial replication, and conferred 60% survival in this model where all unvaccinated animals died within 4 days of challenge. The F1 DNA construct was not protective despite inducing T-cell immunity and was redesigned using information from the literature to address this deficiency. Conclusion These results are promising for the needle-free DNA/jet vaccine platform against bacterial pathogens, and studies of LcrV DNA combined with redesigned F1 DNA are in progress. Funding Source DTRA-JSTO Topic Categories Vaccines and Immunotherapy (VAC)

Increasing the Efficacy of Chemotherapy by Rescuing the Innate Immune Response 2309649

Abstract Introduction Despite advancements in immunotherapy, more than half of melanoma patients will either not respond or will later relapse after treatment with immune checkpoint blockade (ICB). For later-stage patients, chemotherapy is an essential treatment modality, but tumor intrinsic cell survival mechanisms and an immunosuppressive tumor microenvironment often limit efficacy. We recently discovered that by upregulating the secretion of Pros1, tumor cells limit the response of macrophages to chemotherapy released tumor Damage Associated Molecular Patterns (DAMPs). By pharmacologically inhibiting Ptp1b, a signaling intermediary downstream of the Mer receptor, macrophage responsiveness to DAMPs can be restored. This is associated with increased macrophage M1 polarization and immune infiltration, as well as a 40-80% decrease in tumor volume in multiple preclinical models. Methods We hypothesize that because Ptp1b inhibition prevents tumor suppression of DAMP responsiveness, combining Ptp1b inhibition may improve the efficacy of multiple chemotherapies, particularly those that promote necrotic and immunogenic cell death. To test this, macrophages were co-cultured with murine melanoma cells (B16F10) and cisplatin, doxorubicin, or dacarbazine in the presence or absence of Ptp1b inhibitor via transwell assay, after determining the relative amounts of apoptosis/necrosis produced by each chemotherapy. Results Preliminary results indicate that Ptp1b inhibition significantly increases macrophage pro-inflammatory gene expression by 7.5-fold in a setting of chemotherapy-induced tumor DAMP release. This indicates that inhibiting Ptp1b could synergistically improve chemotherapy effectiveness. Conclusion As Ptp1b inhibitors have a reasonable safety profile based on multiple clinical trials, combining Ptp1b inhibiting drugs with chemotherapy may be a novel way to restore the innate immune response during treatment while also improving patient outcomes. Funding Source NCI- RO1 CA262241(Ubil) Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Bioinspired Electrostatic‐Field Perturbated Sensing for General Material Noncontact Perception

ABSTRACT Noncontact sensing is essential for smart manufacturing and safe human‐machine interaction, yet existing proximity and inspection sensors are often limited by material selectivity, ambient light, and continuous power consumption. Here, we report a bioinspired electrostatic‐field sensor that implements a solid‐state analogue of electrolocation using a corona‐polarized fluoropolymer electret. The pre‐charged electret establishes a quasi‐static electric field, and nearby objects reshape this field to induce measurable potential modulation on a grounded electrode, enabling friction‐free sensing without active emission or mechanical contact. The sensor detects both conductive and dielectric targets (metals, polymers, glass), while waveform features encode material‐dependent electrical signatures. The device achieves a near‐field change in separation sensitivity of 1.05 V per 50 µm and maintains stable responses over 10,000 approach‐withdraw cycles. Combined with machine‐learning models, the platform enables proximity warning, touch‐free interaction, material discrimination, coating‐defect recognition, gesture decoding, and gesture‐to‐robot control. This work establishes electrostatic‐field perturbation as a robust strategy for low‐power, multifunctional noncontact perception.

Bubble Formation Control: Fabrication of Centimeter‐Sized Tissue‐Like Constructs by Catalase‐Coated Oxygen‐Releasing Hydrogel

ABSTRACT Developing thick three‐dimensional (3D) scaffolds remains challenging due to oxygen depletion and limited cell viability. Calcium peroxide (CaO 2 )‐catalase‐based oxygen‐releasing biomaterials are a common solution, but the uncontrolled release of oxygen bubbles often leading to structural damages is rarely discussed. Herein, we present a strategy to control the site of bubble formation in an oxygen‐releasing hydrogel, by applying a catalase nanocoating to its surface. CaO 2 undergoes hydrolytic decomposition with water, generating hydrogen peroxide (H 2 O 2 ), subsequently converts into O 2 and H 2 O. Because H 2 O 2 can induce cytotoxicity, direct catalase incorporation into hydrogel systems may accelerate O 2 bubble formation, leading in hydrogel collapse within 1 h of aqueous immersion. In comparison, catalase‐coated hydrogels exhibited improved structural stability, showing a 5.9‐fold smaller bubble size than hydrogels with mixed catalase after 24 h in ambient air. Under hypoxic conditions (O 2 < 0.1%), centimeter‐scale constructs containing catalase‐coated hydrogels preserved up to 86% viable human fibroblast cells after 5 days of culture, compared with only 47% in non‐catalase coated hydrogels. Furthermore, the incorporation of catalase‐coated hydrogels promoted cell survival and neurite outgrowth of human neural stem cells cultured in neuronal differentiation conditions under severe hypoxia. These findings suggest the potential of the proposed strategy for oxygen‐supportive tissue engineering applications.

Impact of Transplant Type on Infection Risk in Studies of Neutropenic Diets

Reaction-induced surface/subsurface indium species formation on ZrO2 for enhanced CO2 hydrogenation to methanol

HLA-Shuttle: A system for enhancing antigen presentation in immunologically cold tumors 2258016

Abstract Introduction Peptides presented by class-I Human Leukocyte Antigen (HLA-I) proteins provide the basis of immune surveillance. Conversely, reduced surface HLA-I expression is a hallmark of immune evasion in cancers, which confounds the identification of peptide antigens and neoantigens. Here, we outline a system (HLA-Shuttle) for in vitro manipulation of cells with engineered components of the HLA-I processing pathway that improves recovery of the immunopeptidome of immunologically “cold” tumors. Methods HLA-Shuttle is comprised of an engineered variant of the HLA class I chaperone tapasin that bypasses its native degradation and ER retention signals, enabling improved expression and escape from the ER. HLA-Shuttle provides a continuum of chaperoning activity for HLA-I complexes from their point of assembly in the ER to the cell surface, improving antigen presentation in those cells. Results Our data suggest that HLA-Shuttle functions in a multimodal fashion, both enhancing HLA-I complex production in the ER while stabilizing the folded conformation of HLA-I molecules globally. This is evidenced by increased surface expression of HLA-I, while cellular trafficking assays and single particle tracking reveal an extension of their cell-surface lifetimes and microdomain formation, implying an enhancement in their stability. Leveraging this technology, we captured the immunopeptidomes of neuroblastoma cell lines. We observed improved immunoprecipitation of HLA-I complexes, which correlated with a significant expansion of the observable immunopeptidome in immunologically cold neuroblastoma cells. Following bioinformatics analysis to search for therapeutically relevant peptides, we identified multiple novel tumor associated antigens (TAAs) from both known and novel cancer immunotherapy targets. Conclusion In conclusion, HLA-Shuttle restores antigen presentation in immunologically cold tumor cells, facilitating identification of TAAs with favorable therapeutic potential. Funding Source T32 Fellowship Topic Categories Classical and Non-Classical Antigen Presenting Cells (APC)

CD96 as a target to reverse aryl hydrocarbon receptor mediated immune suppression in aged individuals 2260343

Abstract Introduction Influenza virus is a major source of morbidity and mortality throughout the world. The majority of deaths and hospitalizations from seasonal influenza infection occur in older individuals. Even with high dose or adjuvanted vaccines, influenza vaccine responsiveness is lower in older individuals. Methods We collected plasma and peripheral blood mononuclear cells from 96 individuals over the age of 65 and 14 under the age of 40 prior to and 7,14, and 30 days after receipt of the seasonal influenza vaccine. We assessed antibody responses to the hemagglutinin and neuraminidase components of the vaccine as well as hemagglutination inhibition titers as an established correlate of protection. We further assessed the B cell compartment of each donor using spectral flow cytometry, and selected donors by single cell RNA sequencing. Results Transcripts and protein of CD96 were upregulated in naïve B cells of aged individuals. CD96 is a known inhibitory receptor in T and NK cells but its function in B cells is largely unknown. CD96 interaction with its ligand CD155 inhibited B cell receptor (BCR) crosslinking-mediated calcium flux. We developed a panel of human anti-CD96 antibodies by phage display and found that these antibodies could block CD96-mediated BCR signaling suppression. Metabolomic and transcriptomic data indicated alterations in tryptophan metabolism toward the kynurenine pathway in older individuals, and kynurenine, an aryl hydrocarbon receptor (AHR) agonist, induced CD96 expression in B cells. Kynurenine suppressed antibody production and class switching in a B-T follicular helper cell coculture model, and CD96 blockade reversed the suppressive effect of kynurenine in this model. Conclusion Accumulation of kynurenine and related AHR agonist metabolites may play a role in age-related immune suppression and vaccine hyporesponsiveness in part via upregulation of CD96 on B cells. Blocking CD96 signaling represents a potential avenue to restore vaccine responsiveness in older individuals. Funding Source NIH U01AI165442 Topic Categories Lymphocyte Differentiation and Peripheral Maintenance (LYM)

Therapeutic intranasal delivery of NanoSTING provides broad protection against seasonal and highly pathogenic influenza strains 2258688

Abstract Introduction Seasonal and highly pathogenic influenza strains pose major public health challenges. Broad-spectrum therapies that protect vulnerable populations, accelerate recovery, and reduce mortality are a long-sought goal for influenza. We developed NanoSTING, a liposomal formulation of 2’3’-cGAMP, the endogenous STING-activator, to activate mucosal innate immunity as a host-directed therapy. Methods NanoSTING stability was assessed by DLS, zeta potential, and HPLC. Pharmacokinetics (PK), pharmacodynamics (PD), and safety were assessed in BALB/c mice after a single intranasal dose of NanoSTING. The nasal/lung tissues were analyzed by qPCR for IFN genes (Ifnb1 and Cxcl10) and by H&E for safety. To model vulnerable populations, we tested aged (18—20 mo), cyclophosphamide-lymphodepleted, and dexamethasone-treated (immune-suppressed) mice for NanoSTING-induced mucosal IFN responses, safety, and protection in viral challenge. Therapeutic efficacy was tested against influenza (A/H1N1pdm, B/Brisbane, and H5N1) challenge models. Results NanoSTING was stable for 12 months at 4ºC with no loss of encapsulated cGAMP. A single intranasal dose induced robust Ifnb1 and Cxcl10 in nasal and lung tissues without histologic injury. In influenza A/H1N1 and B challenge models, one dose of NanoSTING reduced weight loss, accelerated recovery, and outperformed ten doses of oseltamivir. In models with highly pathogenic avian influenza (HPAI, H5N1), NanoSTING reduced viral titers and disease severity even when administered 48—72 h post-infection. NanoSTING-induced nasal innate immunity was preserved in lymphodepleted, dexamethasone-treated, and aged mice, supporting its use in vulnerable hosts. Conclusion Single-dose intranasal NanoSTING activates protective type I IFN programs and delivers broad therapeutic benefit across influenza A/B, including H5N1, with an extended treatment window, refrigeration stability, and dose-sparing administration—highlighting a cellular, host-directed path to durable respiratory antiviral defense. Funding Source NIH, AuraVax Topic Categories Mucosal and Regional Immunology (MUC)

Diverse resident memory T-cell subsets differentiate in tumors to promote antitumor immunity and response to immune checkpoint blockade immunotherapy 2254428

Abstract Introduction The accumulation of CD103+CD8 resident memory T (TRM) cells in tumors is predictive of a response to PD-1 blockade. However, the nature of the TRM subsets regulating the response to other immune checkpoint inhibitors and their differentiation mechanisms in the tumor remain unclear. Methods Mouse tumor models, human cancer samples and cohorts, scRNAseq, immune cell imaging and functional assays. Results Our results show that while CD103+CD8 TRM promote the response to anti-PD-1 neutralizing antibodies, CD49a+CD4 TRM promote the response to anti-CTLA-4. Single-cell RNA sequencing on mouse tumor-infiltrating T lymphocytes (TIL) reveals a CD49a+CD4 TRM signature enriched in CTLA-4, ICOS, RUNX and residency-linked transcripts, amplified upon CTLA-4 blockade. Anti-CTLA-4 therapy leads to intratumoral expansion of CD49a+CD4 TRM and an increase in CD4 TIL-mediated cytotoxicity toward tumor cells. A CD49a+CD4 TRM signature enriched in CTLA-4 and cytotoxicity-linked transcripts is identified in TIL from human lung tumors and melanomas. Multiplex fluorescence immunohistochemistry on cohorts of anti-CTLA-4-plus-anti-PD-1-treated melanomas shows that an increase in the density of CD49a+CD4 TIL is associated with higher rates of progression-free survival. Our results also show that the formation of CD49a+CD4 and CD103+CD8 TRM in human lung tumors involves distinct transcription factors, and that the differentiation of functional CD4 and CD8 TRM within the tumor microenvironment requires different signaling pathways. Moreover, CD4 and CD8 TRM subsets display phenotypic and functional heterogeneity, and undertake distinct cellular interactions and molecular signals for potent cytotoxic activity and tumor progression control. Conclusion Our results support the conclusion that different CD4 and CD8 TRM subpopulations participate to antitumor immunity and response to immune checkpoint blockade, and that their differentiation in the tumor relies on specific cellular interactome and distinct signaling programs. Funding Source INCa Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

Early Growth Response 2 (EGR2) Regulates Late B Cell Differentiation and Double-Negative T Cells in Lupus-Prone MRL/lpr Mice 2307921

Abstract Introduction Early Growth Response 2 (EGR2) is a zinc-finger transcription factor known to regulate T cell activation and tolerance; however, its role in B cell differentiation in lupus remains unclear. To define its function, we generated conditional Egr2 deletion in lupus-prone MRL/lpr mice and investigated its impact on B cell differentiation and pathogenic double-negative T (DNT) cells. Methods We generated CD2-Cre Egr2-deletion MRL/lpr mice and analyzed their immune phenotype. Using flow cytometry, we profiled splenic B cell subsets, germinal center (GC) B cells, plasmablasts, and double-negative T (DNT) cells. Serum immunoglobulins and autoantibodies were measured by ELISA. To assess immune activation and pathology, we evaluated IL-17 induction in stimulated splenocytes and performed histopathological scoring of major organs. Results Egr2 deletion caused a significant reduction in marginal zone B cells while sparing follicular B cells. GC B cells were markedly increased, but plasmablasts were significantly reduced, indicating impaired late B cell differentiation. DNT cells were dramatically decreased, accompanied by reduced IL-17 induction. Total IgG, IgM, anti-cardiolipin, and anti-Sm levels were unchanged. Histopathology showed a trend (but statistically not significant) towards reduced kidney inflammation but increased lymphoid hyperplasia and lung involvement. Conclusion EGR2 is a key regulator of B cell maturation and DNT cell expansion in lupus. Its deletion disrupts late B cell differentiation and alters tissue pathology, revealing a central transcriptional control mechanism in lupus immunopathogenesis. Funding Source Virginia—Maryland College of Veterinary Medicine (VMCVM), Virginia Tech Topic Categories Basic Autoimmunity (BA)

BCR Density Regulates IgE Germinal Center B Cell Survival 2254802

Abstract Introduction IgE antibodies mediate allergic disease, yet IgE+ B cells rarely persist in germinal centers (GCs). Low B cell receptor (BCR) density has been implicated in this instability, potentially due to three non-canonical polyadenylation sites downstream of the last IgE membrane exon, which are less efficient than the canonical secreted polyadenylation site (spA). However, how BCR density affects IgE GC survival remains unclear. Methods CRISPR-Cas9 gene editing was used to delete the secreted polyadenylation site (spA) at the IgE (IgEspAd) or IgG1 (IgG1spAd) locus. Mice were challenged intranasally with Alternaria alternata to elicit IgE responses. Flow cytometry was used to quantify GC B cells, plasmablasts, and surface BCR density, and to assess apoptosis using active caspase-3 staining. IgEspAd—wild-type mixed bone marrow chimeras were generated to distinguish the effects of BCR density from secreted IgE. Results Deletion of spA in IgEspAd mice abolished secreted IgE and increased surface BCR density, reducing IgE GC B cells and plasmablasts. IgG1spAd deletion greatly reduced secreted IgG1 but did not affect density. In IgEspAd—wild-type chimeras, IgEspAd-derived GC B cells showed reduced apoptosis, demonstrating that elevated BCR density promotes GC survival. Verigem mice, which retain secreted IgE while exhibiting increased BCR density, also showed reduced apoptosis and modestly increased IgE GC B cell numbers, supporting a role for secreted IgE in maintaining GC persistence. Ongoing 10x single-cell analysis will determine how enhanced IgE GC survival influences somatic hypermutation. Conclusion These findings identify BCR density as a key determinant of IgE GC B cell survival and define a molecular mechanism that constrains IgE responses. By linking BCR regulation to IgE GC B cell survival, this work highlights potential strategies to manipulate IgE immunity in allergy and immunotherapy. Funding Source NIH Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

Mapping Galectin-3 Ligand Networks Driving Renal Fibrosis Using Proximity-Labeling Proteomics 2253572

Abstract Introduction Galectin-3 (Gal-3) is a β-galactoside—binding lectin implicated in inflammation, epithelial injury, and fibrosis. Although Gal-3 is strongly upregulated in inflamed kidneys, its role in promoting renal fibrosis remains poorly defined. We hypothesized that Gal-3 interacts with cell-surface receptors that trigger profibrotic signaling during tubular injury. Methods To identify Gal-3—associated ligands, we generated a Gal-3—APEX2 fusion construct that enables proximity-dependent biotinylation of neighboring proteins in live BUMPT kidney proximal tubule epithelial cells. Cells were stimulated with TGF-β (0—10 ng/mL, 24 h) and treated with biotin-phenol/H₂O₂ to induce APEX2-mediated labeling. Results Immunofluorescence (IF) staining and western blot (WB) confirmed robust Gal-3-dependent biotinylation localized to the plasma membrane and perinuclear regions. Quantitative IF revealed dose-dependent increases in Gal-3 proximity activity at concentrations of 25 nM (FC = 16.6, p < 0.01), 50 nM (FC = 40.5, p < 0.0001), and 100 nM (FC = 88.7, p < 0.0001) with TGF-β incubation (10ng/ml). WB analysis showed a 2.7-fold increase (t = 36.5, p = 0.0007) in labeled proteins in TGF-β—treated cells (10ng/ml). Tandem-mass-tag proteomics identified 41 upregulated proteins (FC > 1.2 — 7.5) following TGF-β stimulation, including extracellular matrix components (TNC, TSP1, TIMP3), adhesion molecules (EPCAM, CLDN7, JAM3), and receptors (EPHA2, TLR2, SLC3A2). Mitochondrial and metabolic enzymes (SLC2A1, SHMT2, SDHB, IDH2) were also enriched, suggesting Gal-3-driven metabolic activation. Conclusion These findings demonstrate that Gal-3 proximity labeling enables proteome-wide mapping of Gal-3 interactors in renal epithelial cells. TGF-β—induced Gal-3 activation promotes recruitment of adhesion, metabolic, and extracellular matrix proteins, defining a molecular framework for Gal-3—mediated epithelial activation and fibrosis. Funding Source n/a Topic Categories Cellular Adhesion, Migration, and Inflammation (CAM)

Macrophage—Treg immunopathology in mucosal chronic graft-versus-host disease defined by single-cell and spatial profiling 2309654

Abstract Introduction Chronic graft-versus-host disease (cGVHD) is an alloimmune complication of allogeneic hematopoietic stem cell transplantation driven by donor—recipient antigen mismatch. The oral mucosa is a frequent target; however, the cellular circuitry and spatial architecture that sustain oral cGVHD remain incompletely defined. Methods Using single-cell RNA sequencing, we observed a marked enrichment of macrophage subsets in cGVHD oral mucosa. Spatial transcriptomics mapped CD68+ macrophages preferentially along the epithelial basement membrane. Ultrahigh-plex spatial phenotyping further delineated a significant expansion of proinflammatory (M1-like) macrophages, defined by HLA-DR, CD86 expression, accompanied by elevated IL-17 within lesional regions. Results These data suggest an IL-17—driven axis in M1 macrophage recruitment and activation that may amplify mucosal inflammation. Spatial proximity analyses demonstrated juxtaposition of M1 macrophages with CD4+ regulatory T cells (Tregs) in cGVHD tissue, yet TIGIT+ Tregs were comparatively reduced, consistent with impaired regulatory—myeloid crosstalk. Ligand—receptor inference identified upregulation of JAK-STAT signaling, including increased CXCL10—CXCR3 interactions, suggesting chemokine-guided positioning of effector cells. Clinically, strategies that expand Tregs or antagonize CSF1R to limit macrophage activity have shown benefit in cGVHD, underscoring the therapeutic relevance of these pathways. Co-culture assays with macrophage-Treg cells are needed to probe reciprocal effects on cytokine production, Treg suppressive capacity, and macrophage polarization with verification in cGVHD patients. Conclusion Collectively, these studies may define macrophage—Treg crosstalk as an important determinant of immune disequilibrium and tissue injury in oral cGVHD. Funding Source Intramural program of the NIDCR, NIH Topic Categories Transplantation Immunology (TRAN)

Low-Dose Tamoxifen in Noninvasive Breast Neoplasia: Long-Term Results From an Individual-Participant Data Pooled Analysis

PURPOSE Tamoxifen 20 mg once-daily reduces the risk of breast cancer recurrence after ductal carcinoma in situ (DCIS), but its use is limited by adverse effects. Lower doses may be effective, but benefit durability and differences according to menopausal status and site of recurrence remain uncertain. METHODS We conducted an individual-participant pooled analysis of three clinical studies involving women with estrogen receptor–positive or unknown DCIS, microinvasive carcinoma, or high-risk breast lesions. Participants received low-dose tamoxifen (5 mg once daily or 10 mg once-every other day for 2-5 years) or a control intervention. The primary end point was breast cancer–free interval, defined as the first occurrence of any ipsilateral or contralateral invasive breast cancer, DCIS, regional recurrence, or distant recurrence. Hazard ratios (HRs) were estimated with mixed-effects Cox models accounting for between-study variability. RESULTS Among 1,545 women included with a median follow-up of 9.4 years, low-dose tamoxifen reduced breast cancer events overall, with evidence of treatment heterogeneity according to menopausal status ( P = .01). In postmenopausal women, breast cancer events occurred in 40 of 335 receiving low-dose tamoxifen versus 93 of 401 controls (HR, 0.51 [95% CI, 0.35 to 0.73]), with a 10-year absolute reduction of 11.2%. Among premenopausal women, no significant reduction was observed (HR, 0.90 [95% CI, 0.70 to 1.17]), although contralateral breast cancer was reduced (HR, 0.45 [95% CI, 0.26 to 0.76]). Serious adverse events were infrequent and similar between groups. CONCLUSION Low-dose tamoxifen was associated with a sustained reduction in breast cancer events, with differences by menopausal status and site of event. These findings support endocrine dose de-escalation to improve the benefit-risk profile of preventive therapy in DCIS and high-risk lesions.

A molecular velcro self-healing cement