Browse Articles
Discover research articles across all indexed journals
IP-10 Drives TCF1+ Stem-like CD8+ T Cell Depletion and Terminal Differentiation in Lupus Nephritis 2308427
Abstract Introduction Lupus nephritis (LN) is characterized by kidney damage due to immune dysregulation. CD8+ T cell dysfunction contributes to tissue injury, however, the mechanisms regulating CD8+ T cell fate during autoimmunity remain unclear. In particular, the effect of inflammatory chemokines on the balance between stem-like and terminally differentiated CD8+ T cells in the LN is poorly understood. Here, we investigated whether IP-10 acts as a key regulator of CD8+ T cell differentiation and tissue redistribution in the LN. Methods Plasma levels of 105 immune-related proteins were profiled in HC, patients with SLE, and patients with LN. Using longitudinal analyses of MRL/lpr lupus mice, we performed multiplex profiling of circulating inflammatory mediators together with immunophenotypic analysis of splenic and renal CD8+ T cell subtypes, including TCF1+ stem-like, effector, terminally differentiated and PD-1+ cells. Correlation analyses linked IP-10 levels with immune mediators and CD8+ T cell subtypes, and functional relevance was assessed using anti-IP-10 antibody treatment in MRL/lpr mice. Results Among the 105 circulating factors analyzed, IP-10 showed the highest elevation. and showed strong correlations with immune checkpoint molecules, particularly with TIM-3. In MRL/lpr mice, IP-10 was markedly elevated during disease progression and showed strong correlations with BAFF, IL-15, TIM-3, and PDL2. Increased IP-10 levels were also associated with a progressive loss of TCF1+ stem-like CD8+ T cells and a concomitant enrichment of terminally differentiated and PD-1+ CD8 T cells within the kidney. Blockade of IP-10 restored the attenuated pathogenic immune activation. Conclusion Our data reveal IP-10 as a key regulator of CD8+ T-cell fate in the LN. By promoting stem-like CD8+ T-cell depletion and terminal differentiation, IP-10 contributes to the sustained renal immune injury. Modulation of the IP-10—CXCR3 pathway may offer new opportunities to reprogram pathogenic T cell responses in chronic autoimmunity. Funding Source This work was supported by the National Research Foundation of Korea (RS-2024-00348380, RS-2022-NR069963). Topic Categories Basic Autoimmunity (BA)
Cell cycle-coupled transcriptional network regulates human B cell fate bifurcation 2257411
Abstract Introduction Antibody response quality and durability depend on activated B cells bifurcating into plasmablast (PB) or germinal center B cell (GCBC) fates. PBs are short-lived and secrete low-affinity antibodies, whereas GCBCs undergo somatic hypermutation and selection before potentially generating long-lived plasma cells that produce high-affinity antibodies. The gene regulatory networks (GRNs) governing these trajectories in human B cells remain poorly defined. Methods We profiled in vitro—activated human B cells using time-series single-cell multi-omics (RNA/ATAC-seq) and applied machine learning to predict linkages between transcription factors (TFs), cis-regulatory elements, and target genes, building B cell state-specific GRNs. Using these GRNs, we simulated TF perturbations and tested the predicted effects using CRISPR screening in primary B cells. Results Simulations and experiments converged with predictions of TF activity at single-nucleotide resolution, revealing dominant and reciprocal actions of IRF4 and partners at IRF-related motifs. Single-cell perturbation analysis uncovered a reciprocal negative feedback loop that modulated B cell fate choice, involving BATF, IRF4 and BLIMP1. Additionally, we found that IRF4 and BLIMP1 co-repressed the cell cycle regulator MYC before PB differentiation. G0 lengthening accelerated the switch to a IRF4hi/BLIMP1hi state and enhanced the probability of PB specification, thereby generating a self-reinforcing regulatory module that couples cell cycle dynamics to B cell fate choice. Conclusion This work establishes a generalizable framework for assembling and testing GRNs in the context of immune cell fate decisions. Applying this approach to human B cells revealed previously unreported feedback loops that link cell division to fate specification. These findings have implications for strategies to modulate antibody responses in humans. Funding Source Cancer Research Institute (#4185) ; NIAID (#5T32AI089443) Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)
A causal link between autoantibodies and neurological symptoms in long COVID 2309692
Abstract Introduction Acute SARS-CoV-2 infection triggers the de novo production of diverse and functional autoantibodies (AABs), even after mild illness. Previous studies have shown that autoantibodies remain persistently elevated in a subset of individuals with Long COVID (LC). However, it is still unclear whether these autoantibodies drive pathogenesis of LC Methods Using a human protein array with over 21,000 proteins and an antibody pull-down of autoantigens followed by mass spectrometry, we identified a broad range of AAB targets among individuals with LC that correlated with their symptom profiles. In order to evaluate if those autoantibodies were pathogenic, we developed a passive transfer mouse model by injecting total IgG in mice and performing a battery of behavior analysis. Results We found increased AABs against proteins in the central and peripheral nervous systems, as well as peripheral tissues, in individuals with LC displaying neurocognitive and neurological symptoms. Purified immunoglobulin G (IgG) samples from these individuals reacted with tissue sections of human locus coeruleus, thalamus, adrenal gland, thyroid, and showed cross-reactivity with mouse sciatic nerve and meninges. Autoantibody levels reactive to CNS antigens were linked to symptoms such as headaches and loss of taste and smell. Passive transfer of IgG from patients to naïve mice caused increased fatigue-like behavior and thermal hyperalgesia, aligning with patients’ reports of chronic pain. Similarly, loss of balance and coordination in the rotarod test in mice injected with IgG matched with patient-reported dizziness. Moreover, transfer of purified IgG from patients with chronic pain caused damage to small peripheral nerve fibers and increased neuronal activity in pain-related brain regions in mice. Conclusion Our findings demonstrate that transferring IgG from LC patients into mice can reproduce certain neurological symptoms, suggesting that targeting AABs might offer therapeutic benefits for this subgroup of LC. Funding Source Pew Latin American Fellowship Topic Categories Immune Mechanisms of Human Disease (HUM)
Metformin fails to replicate the metabolic phenotype of Compound 991 treatment in primary human T cells 2309421
Abstract Introduction Chimeric Antigen Receptor T cell (CART) therapy, while highly effective at inducing remission in leukemia patients, only has long-term cure rates of 50%, due in part to short in vivo persistence of the CAR T cells. Previous data demonstrate that pre-infusion treatment of CAR T cells with Compound 991 (991), a direct agonist of AMP-activated protein kinase (AMPK), increases their in vivo potency. However whether metformin, an FDA approved compound, is equally efficacious is unknown. Methods To determine if metabolic priming with metformin produces a metabolic phenotype similar to 991, human T cells (n = 4) were stimulated with CD3/CD28 Dynabeads, cultured with DMSO (vehicle control), metformin, or 991 on days 5 and 7, then rested on day 9. Glucose assays were conducted on culture media from day 9 and oxygen consumption was measured via Seahorse following restimulation on day 11. Immunoblots for phosphorylated Raptor, a downstream target of AMPK, determined pathway activation. Results Doses of 300μM Metformin and 25μM 991 were deemed equivalent based on phosphorylation of ULK1, a downstream target of AMPK. Mitostress assays demonstrated significantly higher basal (p = 0.007) and maximal (p = 0.014) oxygen consumption rates, as well as a higher spare respiratory capacity (p = 0.028), in human T cells treated with 991 as compared to metformin. 991-treated cells also showed significantly reduced glucose utilization (p < 0.0001), a proxy for increased autophagy, with a trend towards elevated Raptor phosphorylation. Conclusion Our results suggest that in human T cells, AMPK activation by metformin does not replicate the metabolic changes conferred by 991 treatment . Based on these results, we predict that distinct pathways of AMPK activation will likely result in different functional outcomes, a premise we are currently testing with 41BB CART cells in vivo. Funding Source Cancer Research Education And Training Experience NIH NCI 2R25 CA200508-07 University of Minnesota Department of Pediatrics startup fund Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)
Single-Cell sequencing Reveals Dynamic Intraepithelial Lymphocyte Responses to Salmonella Enteritidis Infection in Chickens 2257021
Abstract Introduction Intraepithelial lymphocytes (IELs) represent a heterogeneous population of immune cells located at the interface between the intestinal lumen and the lamina propria. Due to this unique anatomical location, IELs play a crucial role in maintaining intestinal homeostasis and providing mucosal immune defense against innocuous and pathogenic agents. However, the cellular mechanisms and functional roles of IELs during enteric infections in chickens remain poorly understood. This study aimed to elucidate the cellular and molecular mechanisms underlying IEL responses during Salmonella infection in chickens. Salmonella is a major foodborne pathogen of global concern, posing significant threats to both poultry production and public health. Methods In this study, sixty 21-day-old SPF chicks were orally challenged with Salmonella Enteritidis (1.6 × 108 CFU/mL; n = 30), while another 30 birds served as uninfected controls. Ileal samples were collected from eight birds per group at 2- and 6-days post-infection (dpi), and IELs were isolated for flow cytometric analysis. Enriched IELs from 2 dpi were further analyzed using single-cell RNA sequencing. Results At 2 dpi, infected group exhibited a significant increase in IEL frequency, particularly the CD8αα+TCRαβ+ and CD8αα+TCRγδ+ subsets, whereas IEL frequencies were comparable between groups at 6 dpi. Preliminary transcriptomic analysis identified 12 distinct cell clusters, including 5 lymphoid, 3 myeloid, and 4 epithelial populations. Within the lymphoid clusters, upregulated genes were associated with cell cycle progression, immune signaling, metabolic reprogramming, leukotriene signaling, granule release, proinflammatory responses, immune cell recruitment, apoptosis, cytotoxicity, and cell proliferation. Conclusion These results provide new insights into the cellular heterogeneity and transcriptional profiles of chicken IELs, highlighting their dynamic role in coordinating intestinal immune responses during Salmonella infection. Funding Source n/a Topic Categories Veterinary and Comparative Immunology (VET)
Bystander activation in CD8 memory T cells is an innate program that is standalone from, yet influences TCR and TCR-driven responses 2259216
Abstract Introduction T cell receptors (TCRs) bestow CD8 memory T cells with their conventional function: highly-effective and -specific target killing. While TCR is critical to unlock these effector functions, CD8 memory T cells can become innate-like effectors when activated by proinflammatory cytokines in combination (a phenomenon referred to as bystander activation). Given the parallels between TCR-mediated and bystander activation, including IFNg secretion, cytolytic granule expression, and upregulation of co-inhibitory molecules and transcripts suggestive of TCR signals, there has been significant controversy as to whether bystander activation utilizes TCR or downstream machinery. Methods We use a combination of TCR signaling inhibitors, targeting of CD3e using CRISPR/Cas9 at priming, and inducible TCR deletion at T cell memory to dissect the TCR-dependent and -independent consequences of bystander activation. We use in vitro stimulations and in vivo heterologous infections to bystander activate CD8 memory T cells with defined specificity. Results We demonstrate that bystander activation induces cytotoxicity completely independent of TCR, downstream signaling components like NFAT, and regulators of TCR signaling, demonstrating that bystander activation is a standalone innate program conserved in adaptive cells. On the other hand, we report that the expression of co-inhibitory molecules (like PD-1) during bystander activation requires intact TCR expression. This suggests inflammation may be able to lower TCR activation thresholds needed to unlock co-inhibitory/-stimulatory molecule expression. Conclusion We show that CD8 memory T cells are capable of conventional adaptive (TCR-driven) responses as well as those that are entirely innate. Though this innate activation does not require TCR/TCR signaling machinery, it can influence how a T cell interprets sub-agonist and agonist signals through its TCR. Future work will be necessary to dissect the interplay between the innate and adaptive programs of T cells. Funding Source NCI K00 CA245735 (NJM), NCI K99 CA296729 (NJM), DRG-2427-21 (NNJ), NIAID K22 AI177360 (NNJ), NIAID R01 AI038903 (SCJ) Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)
3D‐Printed Ultra‐Thin Solid Polymer Electrolytes with Superior Dielectric Properties for Wide Temperature Range All‐Solid‐State Batteries
ABSTRACT The development of all‐solid‐state batteries (ASSBs) is critical for overcoming the safety and performance limitations of conventional lithium‐ion batteries with liquid electrolytes. Solid polymer electrolytes (SPEs) offer promising processability and interfacial contact but suffer from low room‐temperature ionic conductivity. Liquid crystal electrolytes (LCEs) have emerged as a solution, leveraging their self‐assembling mesophases to create ordered ion transport channels that enhance conductivity. However, translating the molecular advantages of LCEs into high‐performance devices requires advanced manufacturing techniques capable of precise structural control. This work introduces a novel 3D‐printed, ultra‐thin (20 µm) composite LCE membrane engineered for high dielectric constant ( ε r ′ ∼ 40) and ionic conductivity (~10 −3 S cm −1 ). The membrane is composed of a polymer matrix (PVDF), a polymer network formed by the reaction of liquid crystal (LC) monomer RM257 and thiol monomers, and the high‐dielectric small molecule LC 4‐cyano‐4′‐pentylbiphenyl (5CB). When integrated into ASSBs with a lithium metal anode and LiCoO 2 cathode, the printed LCE membrane enables outstanding long‐term cycling stability (retaining a capacity of 76.6% over 3000 cycles). This study demonstrates that combining molecular design with additive manufacturing provides a powerful strategy for developing high‐performance, durable, and safe ASSBs.
Investigating the effect of variable interferon signaling on CD4+ T cells 2307707
Abstract Introduction Inflammation guides immune responses but must be balanced: too little limits memory formation, while too much causes pathology. IFN-I is induced during infection, yet its role in CD4+ memory differentiation is unclear. Our lab found that CD4+ T cell memory differs after SARS CoV 2 vaccination versus infection, with infection primed cells enriched for IFN I related genes. I hypothesize that stronger IFN-I during priming programs distinct CD4+ memory and alters recall responses. Methods To define how IFN-I signaling shapes CD4+ T cell development and function, we must isolate the effect of IFN-I to just CD4+ T cells. Conventional IFNAR-/- mice cannot tune IFN-I signaling strength to CD4+ T cells, and antibody blockade lacks CD4+ specificity and cannot test strong or sustained IFN-I cues. I will instead use Ifnar1S526A and Ifnar2Y510F mice with gain- and loss-of-function point mutations in IFNAR, respectively, that have been demonstrated in cell lines, enabling more precise tuning of IFNAR signaling and systematic analysis of IFN-I effects on immunity. Results Ifnar1S526A mice retain more Ifnar1 on the cell surface, boosting Ifnar density and signaling duration. These mice have more effector-memory CD4+ T cells through spectral flow cytometry, indicating enhanced IFN-I—driven differentiation. Naive Ifnar1S526A CD4+ T cells show elevated interferon stimulated gene expression by RT-qPCR compared to WT, confirming that the mutation increases baseline IFN-I signaling. We generated Ifnar2Y510F mice that carry a TYK2-disrupting mutation that reduces Ifnar2 signaling and validated by Sanger sequencing as a hypomorphic contrast to hypermorphic Ifnar1S526A mice. Conclusion Together, these gain- and loss-of-function IFNAR mutants provide a tunable system to define how IFN-I intensity programs CD4+ T cell memory. By comparing Ifnar2Y510F and Ifnar1S526A mice, this work reveals how graded IFN-I cues shape CD4+ T cell differentiation. Funding Source T32 Training Grant Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)
Lipid Nanoparticle-Encapsulated mRNA-Targeting CD19 for B and Plasma Cell Depletion in Autoimmune Diseases 2308376
Abstract Introduction Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are autoimmune diseases driven by autoreactive B cells and plasma cells, leading to chronic inflammation and organ damage. Current therapies targeting B cells, such as anti-CD20 monoclonal antibodies, are ineffective in depleting long-lived plasma cells. This limitation highlights the need for novel therapeutic strategies to reset the immune system in these diseases. Methods We developed lipid nanoparticle-encapsulated mRNA (mRNab-LNPs) encoding anti-CD19 antibodies to deplete autoreactive B cells and plasma cells. mRNab-LNPs were administered intramuscularly to lupus and RA mouse models. We evaluated the therapeutic efficacy by assessing the depletion of CD19+ B cells and plasma cells, and the subsequent reduction in disease-related histopathological damage. Results Intramuscular injection of mRNab-LNPs in both lupus and RA mice led to high and sustained production of anti-CD19 antibodies. This resulted in significant depletion of circulating CD19+ B cells and tissue-resident plasma cells. Histopathological analysis showed reduced damage in the skin, kidneys, and joints of treated mice. Additionally, mRNab-LNPs exhibited favorable pharmacokinetics with prolonged antibody production and minimal systemic inflammatory response. Conclusion mRNab-LNPs effectively target and deplete both B cells and plasma cells in lupus and RA mouse models. These findings suggest that mRNab-LNPs offer a promising alternative to current therapies, providing a safer, more efficient approach to treating autoimmune diseases by resetting the humoral immune system. Funding Source This work was supported by the following grants: National Natural Foundation of China Grant (Nos. 81970632 and 52473328), Guangdong Science and Technology Department Grant (Nos. 2020B1212060018 and 2020B1212030004), Sun Yat-sen Pilot Scientific Research F Topic Categories Therapeutic Approaches to Autoimmunity (THER)
Breaking The Detection Barrier With SMC® 2-Plex Immunoassays Revealing Hidden Cytokine Signatures in Autoimmune Diseases 2257825
Abstract Introduction Quantitation of blood biomarkers is critical for understanding of autoimmune diseases driven by chronic inflammatory responses and for identifying new therapeutic targets. Pro-inflammatory cytokines and anti-inflammatory cytokines play key roles in the pathogenesis of various inflammatory diseases. While traditional immunoassays, such as ELISA, have provided valuable insights into normal and pathological processes, ultrasensitive technologies are now revealing previously undetectable cytokines in blood samples. Methods We developed an ultrasensitive immunoassay platform utilizing SMC® technology to address the challenge of quantifying low-abundance proteins in blood. Results This next-generation FemtoQuest™ system enables detection of two analytes in a single assay well, saving time and cost per analyte. Five SMC® 2-plex assays (IL-17A,IL-17F; IL-1β,IL-1α; IL-23,IL-22; TNFα,IL-6; and IL-17A,IL-22) consistently achieved LLoQ as low as 20 fg/mL. The broad dynamic range of these assays enabled quantitation across both healthy and disease samples within a single run. Evaluation of samples revealed elevated levels of IL-17A, IL-23, IL-22, TNFα, IL-6, and IL-1β in serum and plasma samples from individuals with rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis and Sjögren’s syndrome serum or plasma as compared to healthy individuals. Conclusion These results demonstrate the platform’s capability to detect differential cytokine expression patterns across autoimmune conditions. Funding Source n/a Topic Categories Technological Innovations in Immunology (TECH)
Monoclonal antibody therapy augments production of virus-specific CD4 T cells during Australian bat lyssavirus infection of the CNS 2309800
Abstract Introduction Developing therapeutic countermeasures that can target pathogens within the central nervous system (CNS) remains a challenging task. Rabies virus and other lyssaviruses are well-known examples of neurotropic pathogens that can efficiently evade both the host immune response and current therapeutic strategies. Australian bat lyssavirus (ABLV) is a member of the lyssavirus genus and is known to causes disease that is indistinguishable from rabies. Rabies is uniformly fatal once the infection has entered the CNS, and there is currently no effective treatment post-CNS involvement. Previously, our group demonstrated that a single dose of monoclonal antibody (mAb) treatment can prevent mortality even in mice with established CNS infections, and mAb-mediated survival was CD4 T-cell dependent. To investigate the mechanism of enhancement of the host adaptive immune response, we have developed tools to assess the dynamics of virus-specific CD4 T-cells produced in ABLV-infected mice. Methods Using a novel anti-lyssavirus MHC II tetramer, we quantified virus-specific CD4 T-cell responses in the spleens and brains of infected mice that received mock- or mAb-treatment. Results We found evidence of anti-lyssavirus CD4 T-cells in the spleen as early as day 8 post-infection in infected animals, and this population increased until ≥28 days post-infection in infected mAb-treated mice. We also found a higher frequency of anti-lyssavirus CD4 T-cells in the brains of infected mAb-treated mice on day 14 post-infection, when compared to infected, mock-treated mice. Interestingly, although there were fewer ABLV-specific T-cells in the mock-treated animals, these T-cells produced much more IFN-γ than the T-cells isolated from mAb-treated mice. Conclusion Collectively, our data suggests that mAb treatment can alter the T-cell response by augmenting the generation of virus-specific CD4 T-cells and by modulating effector cytokine production by these T-cells. Funding Source U.S. Department of Defense Topic Categories Vaccines and Immunotherapy (VAC)
B cell role in susceptibility to Pneumocystis murina infection in murine strains with a single point mutation in either IRF4 or IKZF3 2309604
Abstract Introduction B cells are typically recognized for their role in producing antibodies as part of the adaptive immune response. However, B cells have other functions in coordinating the immune response to infection, including secreting cytokines and presenting antigen to T follicular helper cells within germinal centers. Recent studies have identified heterozygous germline point mutations in two separate human transcription factors, IRF4 (p.T95R) and IKZF3 (p.N160S) that were associated with B cell dysfunction and an increase in susceptibility to opportunistic infections such as Pneumocystis pneumonia (PCP). PCP cases are increasing among patients without HIV infection, and the World Health Organization has included Pneumocystis, the causative agent of Pneumocystis pneumonia, among the most dangerous fungal pathogens. Methods Two strains of mice were developed with homologous mutations, Irf4T95R and Ikzf3N159S and appear to recapitulate the patients’ immunologic phenotypes. We utilized these mice in a co-housing model of Pneumocystis exposure to further explore the role and function of B cells in a natural infection model. Results By 5 — 6 weeks post initial exposure, all mice were infected with Pneumocystis murina. We found the Irf4T95R homozygous mice, but not the heterozygous mice to be exceptionally susceptible to Pneumocystis infection. Surprisingly, both the homozygous and heterozygous Ikzf3N159S mice were able to clear infection despite the homozygous mice having a delayed antibody response and known dysfunction with B cell development. Conclusion This is supported by prior research demonstrating that while B cells have been shown to be incredibly important in controlling Pneumocystis infection, antibody production alone is not enough to clear infection. Therefore, further studies are needed to understand the role B cells play in coordinating a complete and effective immune response to Pneumocystis infection. Funding Source Intramural Research Program of the NIH Clinical Center Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)
Morning influenza vaccination elicits superior antigen-specific immune responses in adults aged 60-85 years 2256881
Abstract Introduction Increasing evidence suggests that timing of vaccine administration affects immune responses, with some studies indicating that morning influenza vaccination (9:00-11:00) elicits a stronger antibody response than afternoon vaccination (15:00-17:00) in older adults. Existing trials focused on antibody responses, but did not assess induction of T-cell responses, which are also crucial for immunity to respiratory viruses and may contribute to time-of-day dependent vaccine effects. Methods Here, we analyzed data from the randomized controlled trial Chrono-Vax to determine the effect of influenza vaccination time on immune responses across a continuous time window from 9:00-17:00 in adults aged 60-85 years. Antigen-specific antibody titers and T-cell responses were measured before and one month after vaccination against three vaccine strains (A/H1N1, A/H3N2, and B/Victoria) with the hemagglutination inhibition and IFN-γ ELISpot assay, respectively. Results Antibody responses between the three randomized vaccination time groups (9:00-11:40, 11:40-14:20, 14:20-17:00) were compared using linear mixed effects models adjusted for baseline antibody titers. Vaccine strain-specific antibody responses were jointly analyzed within a single mixed-effects framework. Morning vaccination (9:00-11:40) resulted in a significantly greater fold increase in antibody titers than early and late afternoon vaccination (11:40-14:20, p = 0.005; 14:20-17:00, p = 0.009). Additionally, a generalized additive mixed model showed a significant effect of influenza vaccination timing on the antibody response (p = 0.012), with the strongest response estimated at 9:00. A similar pattern was observed for influenza-specific T-cell responses, though this effect did not reach statistical significance. Conclusion In summary, our findings indicate that morning influenza vaccination can enhance antibody responses in older adults, suggesting that tailored vaccination timing may improve protection against severe disease in this population. Funding Source This abstract is part of the BioClock Consortium (with project number 1292.19.077) of the research program NWA-ORC, which is (partly) financed by the Dutch Research Council (NWO). Additional funding was received from the Dutch Ministry of Health, Welfare Topic Categories Translational and Interventional Immunology (TI)
HLA Epitope Immunodominance and Concordant Residue Targeting Among Kidney Allograft Recipients with Antibody-Mediated Rejection 2254936
Abstract Introduction Late kidney transplant (KT) rejection is primarily caused by donor-specific antibodies (DSA) that recognize mismatched donor HLA. Yet, the structural features that render certain mismatched HLA alleles highly immunogenic remain poorly understood, limiting our ability to predict and prevent alloantibody formation. To dissect these structural determinants, we isolated HLA-A*01:01 (A1)-reactive B cells from the graft and peripheral blood of a KT recipient (N006) and generated 49 recombinant monoclonal antibodies (Abs). B cell receptor sequencing revealed 17 distinct clonal lineages, and high-resolution epitope mapping of three representative Abs (E07, L02, M07) from immunodominant lineages showed recognition of distinct epitopes near the A1 peptide-binding groove (PBG). We hypothesized that DSA from N006 and other A1-mismatched KT recipients target shared immunodominant epitopes and residues in A1. Methods To define DSA epitopes, we performed cross-inhibition assays using N006 Abs and sera from genetically distinct A1-sensitized KT recipients (n = 10). To identify A1 residues essential for DSA binding, we assessed serum and N006 Ab reactivity to wild-type and single-residue mutant A1 (n = 27) by flow cytometry. Results All N006 Abs recognized A1 epitopes overlapping with those of E07, L02, or M07. Competitive inhibition with E07 and L02, which target non-overlapping epitopes near the A1 PBG, strongly attenuated cohort serum DSA binding (mean MFI reduction: 89.6%). A restricted set of A1 residues governed most DSA interactions. Affinity-matured Abs showed markedly enhanced binding to A1 compared with their Unmutated Common Ancestors. Conclusion Our results reveal that DSA responses in A1-mismatched KT recipients converge on immunodominant epitopes near the A1 PBG through affinity maturation rather than germline encoding. These structural insights define shared determinants of HLA immunogenicity and may guide improved donor-recipient matching and organ allocation. Funding Source NIAID Immunologic Diseases and Basic Immunology T32 (5T32AI007051-47) Topic Categories Transplantation Immunology (TRAN)
Geometric‐Topology‐Driven Membrane Design for Suppressing Polysulfide Crossover in Aqueous Redox Flow Batteries
ABSTRACT Developing highly selective ion‐exchange membranes to suppress active‐species crossover remains a critical challenge in aqueous redox flow batteries (ARFBs). Unfortunately, their practical performance is often compromised by hydration‐induced membrane swelling, giving rise to non‐selective water channels that facilitate catholyte‐anolyte crossover. Herein, we show that geometric topology is a previously overlooked but decisive parameter governing membrane microstructure, hydration behavior, and ion selectivity. Using a coarse‐grained molecular dynamics framework, we reveal a geometry‐driven phase‐separation mechanism under membrane hydration. Isotropic 0D geometric motifs remain uniformly dispersed and promote the formation of highly interconnected yet spatially confined hydration networks, whereas anisotropic one‐ and 2D geometric motifs exhibit a strong propensity to bundle and aggregate, inducing phase separation and interfacial voids that promote non‐selective transport. Guided by this principle, a membrane incorporating 0D geometric motifs simultaneously achieves high cationic conductivity and strong polysulfide rejection, enabling stable operation of a polysulfide‐based aqueous redox flow battery for over 700 h with Coulombic efficiencies exceeding ∼99.5% and peak power densities of ∼138 mW cm − 2 , dramatically outperforming conventional commercial membranes and demonstrating the effectiveness of the geometry‐guided membrane design principle in advancing future membrane engineering.
Exploring the Role of Natural Anti-PD-L1 antibodies in Shaping the Anti-Tumor Immune Response to Neoadjuvant Chemo-Immunotherapy in NSCLC 2308226
Abstract Introduction Non-small-cell lung cancer (NSCLC) is a major contributor to cancer-related deaths worldwide. Although the introduction of immune checkpoint inhibitors, such as anti-PD-1, has improved patient survival, treatment responses remain heterogeneous, and the complete mechanisms of action are not yet fully understood. Our group previously described naturally immune checkpoint blockade mediated by endogenous antibodies that functionally mimic the effects of therapeutic checkpoint inhibitors, without autoimmune symptoms in non-previously treated NSCLC patients (Frozza et al., 2025, under review). Now we are investigating the immune profile of NSCLC patients undergoing neoadjuvant anti-PD-1 therapy combined with chemotherapy, with the hypothesis that the presence and dynamic modulation of circulating anti-PD-L1 autoantibodies influence the tumor immune microenvironment, thereby impacting treatment response, immune activation, and therapeutic efficacy. Methods To achieve this, transcriptomic profiling through single-cell RNA sequencing (scRNAseq) of immune cells from blood, tumor and draining lymph node are being performed pre and post treatment, following by the validation with flow cytometry and immunohistochemistry. The quantification of autoantibodies anti-PD-L1 are being performed by ELISA. Results Preliminary analyses demonstrate the presence of circulating anti—PD-L1 autoantibodies both before and after chemo-immunotherapy. Post-treatment antibody levels exhibited marked variability, suggesting heterogeneous immune modulation in response to treatment. scRNAseq showed an increase in the frequency of the CD8+ T and B cell infiltrating the tumor and draining lymph nodes post treatment. Conclusion In conclusion, this study seeks to elucidate mechanisms of immunotherapy resistance in NSCLC by linking tumor immune profiles and the presence of anti—PD-L1 autoantibodies to responses to neoadjuvant chemo-immunotherapy, with the goal of identifying predictive biomarkers and improving treatment strategies. Funding Source PRONON (25000.172780/2019-38), RITEs/FAPERGS (22/2551-0000388-5), FINEP (3088 and 3098), and Universal (405768/2024-0). Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)
Vessel-Associated Microglia Maintain Vascular Integrity and Prevent Early Hemorrhage in Brain Tumors 2308704
Abstract Introduction Microglia are the resident immune cells of the central nervous system, classically studied for neuroinflammation. A specialized subset, vessel-associated microglia (VAM), whose somata directly contact capillaries, constitutes ∼30% of microglia in the naïve brain. Only recently have VAM been recognized as regulators of brain circulation, influencing blood—brain barrier (BBB) integrity and cerebral blood flow, yet their role in pathological vascular remodeling remains unclear. To address this gap, we used glioma models in which peritumoral capillaries undergo extensive vascular remodeling and BBB dysfunction, providing an in vivo platform to probe capillary vulnerability and vascular stability. Methods We combined pharmacological microglial ablation via CSF1R inhibitors with longitudinal in vivo two-photon imaging to visualize microglia—capillary interactions. Behavioral testing, survival analysis, T2-weighted MRI, and immunostaining were performed in parallel. Results Over half of the microglia-depleted mice developed acute, lethal paralysis by 15 days, whereas control tumor-bearing mice remained asymptomatic and survived 30 days. MRI revealed large intracranial hemorrhages and severe edema, and two-photon imaging showed nodular, abnormal vasculature at paralysis onset. The peritumoral region contained dense capillary networks with a marked increase in VAMs (>60%). Genetic lineage tracing confirmed these cells were microglia, exhibiting elongated, vessel-wrapping morphology, also observed following single-vessel photothrombosis and consistent with a response to capillary injury. Conclusion Our findings identify VAMs as critical neurovascular stabilizers that preserve peritumoral capillary integrity and prevent lethal hemorrhage in glioma, highlighting an essential immune role in brain vascular homeostasis. Notably, intracranial hemorrhage has repeatedly emerged across clinical trials of CSF1R inhibitors, raising important safety considerations for CSF1R-targeted therapies in the diseased brain. Funding Source AHA postdoc fellowship (26POST1560008) (J.Z.) Topic Categories Neuroimmunology (NEUR)
Development and Verification of a Novel Multiplex Immunoassay for Immune Profiling in Porcine Models 2257875
Abstract Introduction Multiplex immunoassays play a fundamental role in profiling immune-regulating proteins, including cytokines, chemokines, and growth factors, across both human and animal models. Pigs are particularly valuable in immunology research due to their physiological and genetic similarities to humans, including comparable organ size and immune system function. These similarities make pigs relevant models in translational research. Additionally, their significant presence in the agriculture industry emphasizes the importance of studying porcine health, particularly in the context of livestock management and disease prevention. Methods Here we describe the development of a novel Luminex®-based multiplex immunoassay that can simultaneously detect 32 different cytokines, chemokines, and growth factors in porcine samples. We investigated the expression profiles of these 32 immune mediators across serum and plasma samples from multiple porcine models, including commercial breeds (Yorkshire and German Landrace pigs), and established minipig strains (Hanford, Yucatan, Göttingen, and Sinclair), as well as porcine cell culture supernatants. Results Our findings demonstrate the successful application of this multiplex kit in determining distinct protein expression profiles in serum and plasma samples from multiple porcine breeds and in response to immunostimulants in cell culture models. Conclusion This porcine multiplex immunoassay effectively measures protein expression patterns across diverse porcine breeds and cell lines, supporting both veterinary research and translational studies. Funding Source n/a Topic Categories Veterinary and Comparative Immunology (VET)
Defining the contribution of breast milk immunoglobulins to infant immunity 2309834
Abstract Introduction Infants inherit far more from their mothers than just half of their genes. They also receive mitochondrial DNA, the first seeds of their microbiome, and (perhaps) most remarkably maternal immunological memories as antibodies transferred via breast milk. Despite its importance, the immunological composition of breast milk its role in shaping the developing infant immune system remain poorly understood. Mothers carry a lifetime of distinct antibody specificities, each one recognizing a different pathogen such as virus, bacterium, toxin or vaccine antigen. Yet only a subset of these antibodies is transferred into breast milk. How these antibodies are selected, and whether they shape subsequent vaccine responses in offspring remain unknown. This work will compare breast-milk antibody repertoires to the full maternal repertoire to define the rules governing immune inheritance in early life. Methods We will use the 10x Genomics single-cell platform to profile systemic and mammary-gland plasma cells in murine dams. In parallel, antibodies from breast milk and maternal serum will undergo de novo mass-spectrometry—based sequencing to identify CDR3 signatures and enable clonal mapping between maternal plasma cell repertoires and milk-transferred antibodies. To test whether breast milk antibody transfer is passive or actively programs infant immunity, we will cross foster pups between naïve and vaccinated mothers and immunize them with the same antigen to determine how maternally derived milk IgG shapes the magnitude, quality, and trajectory of subsequent vaccine responses. Results I hypothesize that the selective transfer of maternal IgG into breast milk has the capacity to influence the magnitude and quality of immune responses of IgG vaccine elicited responses in offspring. Conclusion Although IgG is the dominant vaccine-elicited isotype, it remains understudied in maternal-infant immunology. This study will inform strategies to optimize maternal vaccination and enhance early life immunity. Funding Source n/a. Topic Categories Vaccines and Immunotherapy (VAC)
Single Cell Insights on Inflammation-Induced Transitional States in Benign Prostate Hyperplasia 2253526
Abstract Introduction Benign prostatic hyperplasia (BPH) is an age-related prostate enlargement involving epithelial and stromal expansion. Inflammation drives BPH, but its impact on epithelial lineage hierarchies, especially transit-amplifying (TA) states with basal and luminal features, is unclear. We hypothesized inflammation induces epithelial transitions that promote basal-to-luminal differentiation contributing to prostate growth. Methods Using the POET3 inducible prostatitis murine model, inflammation was triggered by OT-1 T cells. Benign prostate stem cells (bPSCs, n = 11) from naïve and inflamed prostates (3 technical replicates/condition) were isolated by FACS and profiled by single-cell RNA sequencing (scRNA-seq, SMARTer, Illumina). Data underwent QC, Seurat integration, cluster annotation, marker analysis, and gene set enrichment. Integrated analysis with an AIRE_KO chronic inflammation dataset assessed conserved versus model-specific responses. Results We identified basal and luminal epithelial populations, with inflammation promoting intermediate states expressing basal (Krt5, Krt14, Trp63) and luminal (Krt8, Krt18) markers. Inflamed cells showed increased proliferation, altered androgen receptor signaling, and elevated pro-inflammatory cytokines (Il1a, Il1b, Ccl2, CxCl2) with EMT-related changes. Integration with chronic inflammation data revealed both conserved and model-specific transcriptional programs, highlighting epithelial heterogeneity. Conclusion This study reveals inflammation-induced intermediate epithelial states and disrupted lineage hierarchies contributing to BPH. These findings could guide therapeutic targeting of inflammatory signaling and epithelial remodeling in BPH and prostate diseases. Funding Source NIH R01DK126478 (PI: Dr. Ratliff) NIH R21ActfAI151723 (PI: Dr. Ratliff) Society for Basic Urologic Research (SBUR) Topic Categories Translational and Interventional Immunology (TI)