Browse Articles

Integrated multiomics profiling reveals MS-specific molecular signatures linked to progression and response to nasal anti-CD3 (Foralumab) therapy 2267524

Abstract Introduction Chronic neuroinflammation in multiple sclerosis (MS) can persist independently of relapse activity, revealing mechanisms of progression not addressed by current therapies. Dysregulated T-cell activity plays a central role in this process and is the main target of nasal Foralumab immunotherapy. Here, we aimed to identify CNS-related biomarkers in the CSF of MS patients linked to disease progression and to define the molecular effects of Foralumab in secondary progressive (SP) MS. Methods We integrated single-cell and proteomic data from PBMC (n = 4) and CSF (n = 23) of MS patients on anti-CD20 therapy or untreated. Data-independent acquisition (DAI) proteomics was performed in CSF of relapsing-remitting (RR) and SP patients. Results CSF proteomic profiling revealed distinct molecular signatures between RR and SP patients. RR samples showed higher levels of immune activation markers (PTPRC, RGS10) and proteins associated with neuronal plasticity and axonal injury (NPTX2, NETO1). In contrast, SP samples were enriched for fibroblast-related proteins involved in tissue injury, fibrosis, and extracellular matrix (ECM) remodeling (FAP, COL8A1), along with elevated cytotoxicity markers (CTSW) and components of the complement cascade. Foralumab treatment significantly reduced the expression of proteins linked to cytotoxic activity (LAMP1), interferon signaling (IFNAR1), tissue injury/fibrosis (COBA1), and NF-κB—dependent inflammation (SIGLEC14, LY86). Notably, increased TGFB1 expression was observed in both CSF and PBMCs, suggesting a regulatory and immunomodulatory effect of the therapy. Conclusion We identified accessible biomarkers distinguishing RR and SP patients and proteins linked to disease progression and found that nasal Foralumab ameliorates MS by increasing TGFB1 and suppressing T cell cytotoxicity and inflammation. Funding Source n/a Topic Categories Computational and Systems Immunology (COMP)

Cardiac Responses to Klebsiella pneumoniae Infection; Investigating Its Role in Sepsis and Endocarditis 2251186

Abstract Introduction Sepsis causes nearly 11 million deaths across the globe and about 350,000 per year in the United States. Sepsis can be induced by various pathogens however, Klebsiella pneumoniae, a gram-negative bacterium, is particularly adept at disseminating through the blood to many distal sites from the lung. K. pneumoniae (Kpn) can cause various illnesses such as pneumonia, meningitis, endocarditis, wound infections, and is a leading cause of bacterial sepsis. The purpose of these studies is to observe how Kpn affects the resident cardiac cells. Methods These studies will be important in elucidating how cardiomyocytes respond to infection with Kpn by using two approaches to uncover how these cells respond to infection. One approach consists of harvesting tissue samples from uninfected and infected mice to observe the in vivo response. Collected tissues were processed using histology techniques then immunofluorescence assays were performed to help delineate immune responses in the heart at post infection. The second approach involved directly infecting rodent and human cardiac cell lines to study the susceptibility of these cells in vitro. Using these two methods, the goal is to define how resident heart cells respond to Klebsiella induced endocarditis. Results Preliminary results show that Kpn infection significantly alters cardiac tissue both in vivo and in vitro. Histological and immunofluorescence analyses demonstrate increased immune cell infiltration and signs of cardiomyocyte stress and damage following infection. Conclusion Our results highlight that Klebsiella pneumoniae infection significantly alters cardiac tissue in vivo and in vitro. Histological and immunofluorescence analyses demonstrate increased signs of cardiomyocyte stress and damage following infection. The data suggest that K. pneumoniae may play a direct role in cardiac dysfunction during sepsis and in the development of bacterial endocarditis, underscoring the importance of early detection and targeted therapies. Funding Source Internal funding - A&M San Antonio Foundation Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

Regulatory T Cell—Derived Amphiregulin Consolidates Transplant Tolerance via EGFR-Mediated T Cell Exhaustion 2263100

Abstract Introduction Durable transplant tolerance remains a major challenge. Prior studies have linked amphiregulin (Areg) to Treg cell stability, anti-inflammatory function, and regulation of T-cell differentiation and tumor immune evasion. As a mitogenic and cell differentiation ligand of EGFR, Areg may enable Tregs to restrain allospecific immune responses by activating exhaustion-associated transcriptional programs such as TOX and Nur77. We hypothesized that Tregs enforce long-term tolerance by inducing controlled Teff cell exhaustion through Areg—EGFR signaling. Methods Using a nonhuman primate model of allogeneic islet transplantation, we integrated high-dimensional CyTOF, donor MHC-II tetramer tracking, and ex vivo coculture assays to define Areg+Treg—EGFR+Teff cell interactions. Functional perturbations included Areg silencing in Tregs and EGFR neutralization/silencing in responder T cells to dissect causal signaling. Results Tolerant recipients displayed enrichment of Areg+ST2+FoxP3+ Treg cells, and HelioshiEOMEShiCCR2+ and EGFR+TOX+Nur77+ exhausted CD8+ T cells within splenic allospecific clusters. Trajectory and pseudotime analyses showed that activated naïve/memory CD8+ Teff cells progressively acquired exhaustion features under Areg+Treg influence. EGFR blockade or Areg knockdown abrogated Treg-mediated suppression, restored cytokine and perforin expression, and diminished TOX+Nur77+TIGIT+ exhaustion. Conclusion These findings establish the Areg+Treg—EGFR+Teff axis as a critical immunoregulatory mechanism that consolidates transplant tolerance by linking Treg-derived Areg signaling to Teff exhaustion. Mechanistically, Areg—EGFR engagement drives TOX—Nur77 transcriptional and metabolic reprogramming, restraining effector activation and sustaining immune quiescence. Funding Source NIH R21 Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)

T Follicular Helper cell and CD8+ T Cell Dynamics in Breast Cancer: Insights from Patient Samples and Immune Checkpoint Blockade in Murine Model 2308437

Abstract Introduction Breast cancer (BC) in India shows distinct epidemiological features, yet immune profiling remains limited. We investigated the role of T follicular helper (Tfh) cells, B-cell subsets, and CD8+ T-cell contributions to anti-tumor immunity in Indian patients and evaluated their modulation in preclinical murine models. Methods Immune cell infiltration in tumor (T) and tumor-draining lymph node (TDLN) samples from treatment-naïve BC patients was analyzed using multiparametric flow cytometry, qRT-PCR, and ELISA. To validate these observations, we utilized an orthotopic murine breast cancer model to examine the impact of immune checkpoint blockade (ICB) therapy. Results Our analysis revealed distinct alterations in Tfh cell frequency, associated with B cell activation signatures in paired BC patient samples, highlighting a potentially underexplored humoral immune axis in the Indian population. CD8+ T cells displayed heterogeneous effector states characterized by high-PD1 expression and other exhaustion markers, suggesting functional diversification of CD8+ T cells in the tumor niche. ICB therapy in a 4T1-induced TNBC mouse model markedly remodeled Tfh and CD8+ T-cell compartments, enhancing cytokine production and strengthening crosstalk with B cells in TDLNs. Although PD-1 expression has been viewed as a marker of T-cell exhaustion, emerging evidence indicates that PD-1high Tfh and CD8+ subsets can retain potent anti-tumor functions. Our study aims to determine how ICB modulates PD-1high immune cell populations–specifically whether therapy alters exhaustion versus effector states and remodels the overall tumor immune landscape. Conclusion Together, these observations indicate that coordinated Tfh—B—CD8 interactions may serve as measurable immunological biomarkers with prognostic and therapeutic relevance. Funding Source ICMR (Sanction No. EMDR/SG/15/2023-1532, dated 04.04.2024) Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Understanding the impact of polyethylene glycol (PEG)-lipids on mRNA-LNP vaccine immunogenicity 2260679

Abstract Introduction mRNA - lipid nanoparticle (LNP) vaccines developed against SARS-CoV-2 are a transformative technology and saved millions of lives during the COVID-19 pandemic. In this vaccine platform, LNPs function as both a delivery agent and a powerful adjuvant. However, the relationship between LNP composition and adjuvanticity is not fully understood, hindering future vaccine design. Methods In this study, we focus on the impact of the Polyethylene-glycol conjugated lipid (PEG-lipid) which is one of the four standard lipids used to make LNPs. PEG-lipids are known to give stability to nanoparticles in solution, control particle size, and impact circulation half-life. We designed mRNA-LNP vaccines that encode SARS-CoV-2 spike as a model antigen, and we modulate the amount of PEG-lipid within the LNP. A comparative vaccination study was performed using BALB/c mice. Results We demonstrate that the amount of PEG-lipid used in the LNP formulation has a significant impact on humoral immune responses to mRNA-LNP vaccines in mice and can impact memory B cell responses. Conclusion These findings support the rational design of novel LNPs to create more tailored and effective mRNA vaccines against both existing and emerging infectious pathogens. Funding Source NIAID, R01AI153064 Topic Categories Vaccines and Immunotherapy (VAC)

Intranasal exposure to SARS-CoV-2 spike protein induces Th2 and Th17 cell-associated pulmonary immunopathology 2258252

Abstract Introduction SARS-CoV-2 spike—based vaccines control COVID-19, yet vaccine-associated enhanced respiratory disease (VAERD) after breakthrough infection remains a concern. We previously reported Th2/Th17-skewed VAERD in hACE2 mice, however, the mechanisms, durability, and effects of vaccine types and routes in this process are unclear and will be investigated here. Methods Wild-type mice received spike protein plus alum/CpG and were challenged with MA10 strain 14 days or 7 months post-boost. Parallel cohorts received intramuscular (IM) mRNA vaccines (Comirnaty or Spikevax) and were challenged at 7 months. Splenocytes were restimulated with spike peptide subpools to map Th2/Th17-associated epitopes. B cell or ITK deficient mice were used to define signaling requirements. We also used model antigen ovalbumin (OVA) as a control to test whether the observed Th2/Th17 phenotype is uniquely associated with intranasal spike following IM subunit vaccination. To further assess booster safety, IM mRNA vaccinated mice were boosted with intramuscular mRNA vaccine or intranasal Ad5-Spike. Results Despite protection, adjuvanted protein vaccination caused severe lung pathology with CD4+ T infiltration and elevated Th2/Th17 cytokines, persisting to 7 months. mRNA vaccines did not induce Th2/Th17-associated VAERD at delayed challenge. Th2/Th17-linked epitopes localized to S1, and both B cells and ITK signaling were required for pulmonary inflammation. Compared with OVA, intranasal spike after intramuscular adjuvanted vaccination recruited additional lung Th17 cells. For boosting, intramuscular mRNA was markedly safer than intranasal Ad5-Spike, which triggered robust Th2/Th17 inflammation. Conclusion VAERD risk can persist long after vaccination and depends on platform and delivery route. Intramuscular mRNA vaccines show superior safety, while spike contains epitopes capable of driving Th2- and Th17-mediated pathology, highlighting the need to refine spike antigens and booster strategies for durable, safe protection. Funding Source n/a Topic Categories Vaccines and Immunotherapy (VAC)

Experimental Validation of Variant Antibodies Guided by a Large Language Model and Optimized through Combinatorial Algorithms 2307181

Abstract Introduction Machine-learning—guided antibody design offers a promising approach for rapidly generating high-affinity therapeutics against emerging pathogens. Our group has developed Ab-Affinity, a large language model that predicts antibody—antigen binding and, together with genetic algorithms and simulated annealing, designs variants with markedly improved predicted stability and affinity for a SARS-CoV-2 spike epitope. Computational analyses indicate over a 160-fold affinity enhancement compared to experimentally derived sequences. This work focuses on experimentally validating these predictions through expression, purification, and functional characterization of the model-designed antibodies Methods Three antibodies–Ab-14-seed and the optimized variants Ab-14-SA-PSSM1 and Ab-14-SA-PSSM6–designed through Ab-Affinity were expressed in Pichia pastoris and purified using FPLC. Protein expression and purity were confirmed by SDS-PAGE and Western blot. Binding affinities are being assessed using ELISA and surface plasmon resonance to evaluate interactions with the target SARS-CoV-2 spike peptide. Results All three designed antibodies have been successfully expressed in Pichia pastoris and purified. Upcoming binding affinity assays will determine whether these variants demonstrate the enhanced binding affinities predicted by Ab-Affinity. Conclusion This study integrates large language model-guided antibody design with experimental validation to assess the real-world performance of computationally optimized antibodies. The results will clarify how effectively AI-generated sequences translate into functional high-affinity binders, informing the development of future therapeutics. Funding Source DOE Topic Categories Vaccines and Immunotherapy (VAC)

Inducible expression of non-classical innate immune genes by a novel DAP-type peptidoglycan sensing and Toll signaling pathway 2266405

Abstract Introduction The Imd and Toll pathways regulate the Drosophila innate response, with each pathway activating distinct NF-κB factors and target genes. These innate immunity signaling cascades are well-studied individually, but how they intersect or cross-regulate is poorly characterized. Methods To identify Toll and Imd interactions, we subjected either wild type, Toll, or Imd pathway mutant flies to a classic Imd challenge — systemic infection with the Gram-negative bacteria Ecc15 and RNA was isolated from the entire animal and analyzed by RNAseq or qRT-PCR. Results These data identified a suit of Ecc15-induced genes that require both Imd and Toll. These Imd/Toll target genes are neither classic Toll genes nor typical Imd targets. These studies revealed that either dead bacteria or DAP-type peptidoglycan alone is sufficient to trigger the induction of two of these Imd/Toll genes, Diedel and TotM, while classic Toll activators, like M. luteus, failed to induce these genes. Nonetheless, Diedel and TotM induction required nearly the entire Toll pathway, except for PGRP-SA - the Lys-type peptidoglycan sensor. Instead, the DAP-type sensor PGRP-SD, along with the orphan co-receptor GNBP2, were critical for this Imd/Toll response. Conclusion These data identify a novel Drosophila innate sensing pathway, where DAP-peptidoglycan triggers a non-canonical Toll-mediated response through the sensor PGRP-SD and co-receptor GNBP2, and contributes to immune gene regulation in conjunction with classic Imd signaling. Funding Source NIH/NIAID Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)

Issue Information

Programmed Delayed Splicing: A Mechanism for Timed Inflammatory Gene Expression 2267628

Abstract Introduction Inflammation involves timed gene expression, suggesting that the fine-tuned onset, amplitude, and termination of expression of hundreds of genes is of critical importance to organismal homeostasis. Recent study of post-transcriptional regulation of inflammatory gene expression led to the suggestion of a regulatory role for pre-mRNA splicing. Methods Here, using a hybrid capture approach to purify incompletely spliced, chromatin-associated pre-mRNAs, we use deep sequencing to study pre-mRNA splicing of the NF-kB transcriptome. To broaden this mechanistic view, we applied deep learning sequence-to-function models (BORZOI) with feature attribution to identify additional regulatory sequences–both intronic and exonic–that may contribute to delayed splicing through mechanisms independent of donor site strength. Results By freezing transcription and examining subsequent splicing of complete transcripts, we find many introns splice tens to hundreds of times slower than average. Investigating the basis of these delays, we focused on evolutionarily conserved introns with suboptimal splice donor sequences and found that strengthening these donor sites by as few as two nucleotides in minigene reporter assays markedly increased gene expression for several targets. This suggests that such sites can act as timing elements that both delay mRNA production and limit expression amplitude. Deep learning approaches with a foundational genomic model revealed non-canonical motifs enriched in slow-splicing introns, pointing to a broader repertoire of cis-elements that can fine-tune transcript maturation during inflammation. Conclusion Together, these findings support a model in which the temporal regulation of pre-mRNA splicing serves as a layer of control in inflammatory gene expression, and raise the possibility that similar timing mechanisms operate in other rapid-response transcriptional programs. Funding Source n/a Topic Categories Computational and Systems Immunology (COMP)

Inflammatory Monocyte Responses and Endothelial Stress in Young Adult E-Cigarette Users 2253631

Abstract Introduction E-cigarettes (ECs) are increasingly used by youth and young adults, but their long-term health risks remain unclear due to limited clinical data. Since bi-directional communication between monocytes and endothelial cells is key in cardiovascular disease (CVD) development, with endothelial cells guiding monocyte activation and monocytes influencing atherosclerosis progression, we investigated how EC use impacts circulating monocytes and primary human endothelial cell function in the context of CVD risk. Methods Adults underwent venipuncture; EC users had ≥6 months of use, while healthy controls (HC) had none. PBMCs were isolated, monocyte subsets quantified by flow cytometry, and classical monocytes (CM) stimulated with vehicle or LPS (100 ng/mL) for 24 hours. To assess vascular effects, HUVECs were exposed to 3% EC liquid (ECL), cigarette smoke extract (CSE), PG vehicle, or media twice daily for 4 days, followed by analysis of adhesion molecules and ROS in supernatants. Results Compared to healthy controls (HC), e-cigarette users (EC) had fewer CD14+CD16⁻ classical monocytes (CM) and more CD14⁻CD16+ non-classical monocytes (NCM). CM from EC produced higher levels of TNFα, IL-6, and IL-1β in response to LPS stimulation than those from HC. HUVECs exposed to EC liquid (ECL) showed increased ROS production, elevated expression of endothelial damage marker CD62P, and upregulation of monocyte adhesion molecules VCAM-1, ICAM-1, and LFA-1. ECL exposure also increased expression of DLL1, a Notch2 ligand critical for CM-to-NCM differentiation. Conclusion Our findings show that e-cigarette (EC) users have fewer classical monocytes (CM) and more non-classical monocytes (NCM), a pattern linked to higher cardiovascular disease (CVD) risk. EC-derived CM released more inflammatory cytokines, and ECL exposure triggered endothelial activation and ROS production similar to cigarette smoke. These results suggest EC use may promote systemic inflammation and endothelial dysfunction, contributing to CVD risk. Funding Source n/a Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

ELISA-Based Neutralizing Antibody (NAb) Detection as a Fit-for-Purpose Alternative to Cell-Based Assays for Biotherapeutic Immunogenicity Assessment 2266841

Abstract Introduction Neutralizing antibodies (NAbs) are a critical component of the adaptive immune response to biotherapeutic agents, capable of blocking biological function, altering pharmacokinetics, and reducing clinical efficacy. Conventional cell-based assays remain the gold standard for NAb detection because they capture functional activity, yet they are inherently variable due to cell-line dependence, receptor expression, and complex assay validation requirements. To address these challenges, we evaluated ELISA-based NAb assays as fit-for-purpose alternatives that model the same ligand—receptor interactions in a controlled, reproducible format. Methods Competitive ligand-binding ELISAs were designed for three representative biotherapeutic classes: monoclonal antibody, peptide drug, and peptibody. Each assay quantified the inhibition of drug—target interaction by NAbs through measurable signal reduction. Reference NAb standards were spiked across defined concentration ranges, and results were benchmarked against published cell-based assay data. Analytical performance was assessed for sensitivity, precision, accuracy, and cut-point determination per ICH M10 and FDA Bioanalytical Guidelines. Results All three ELISA formats demonstrated strong linearity (R² > 0.99) and precision (CV < 10%) across working ranges, with sensitivity comparable to published cell-based data. Inhibition profiles correlated closely with reported cellular responses, confirming mechanistic equivalence in binding blockade. The assays offered enhanced reproducibility, reduced turnaround time, and simplified validation. Conclusion ELISA-based NAb detection represents a scientifically robust, cost-effective, and high-throughput approach for immunogenicity assessment of diverse biologics. By modeling immune neutralization through ligand—receptor competition, this platform provides a fit-for-purpose surrogate to traditional cell-based assays, advancing standardized and reproducible immunogenicity evaluation in translational immunology. Funding Source n/a Topic Categories Technological Innovations in Immunology (TECH)

A distal transcribed enhancer of KRAS fine-tunes Tfh-mediated vaccine response 2308711

Abstract Introduction Enhancer RNAs (eRNAs) are noncoding transcripts from active enhancers whose functions in adaptive immunity are poorly defined. Because small changes in signaling strength can alter T cell fate and B cell help, we hypothesized that eRNAs act as rheostats for key fate decisions and signaling modules shaping antigen-induced immune responses. Methods We integrated rRNA-depleted RNA-seq, ATAC-seq, and ChIP-seq to map transcribed enhancers in human B, CD4, and CD8 T cells. We then focused on a conserved eRNA ∼140 kb upstream of KRAS (eKRAS) and tested its function using si/shRNA, CRISPR perturbations, and phospho-signaling assays in human T cells, together with eKras—/— mice, mixed bone marrow chimeras, influenza infection, and SARS-CoV-2 mRNA vaccination with downstream cellular and serologic analyses. Results We catalogued and characterized ∼2,000 eRNAs in human adaptive immune cells; eKRAS was among the most highly expressed and conserved and functioned as a cis-acting enhancer of KRAS. Disruption of eKRAS reduced KRAS mRNA and attenuated RAS-ERK activation. Although eKras—/— mice developed normally, immunized mixed chimeras revealed a cell-intrinsic defect in T follicular helper (Tfh) differentiation, with impaired germinal center formation, reduced Tfh effector programs, and defective neutralizing antibody responses to protein antigens and influenza. Following SARS-CoV-2 mRNA vaccination, eKras—/— mice showed reduced class-switched anti-spike antibodies. An eKRAS-dependent Tfh transcriptional program was conserved in human blood and associated with neutralizing antibody titers after COVID-19 vaccination. Conclusion We define a systematic catalog of eRNAs in human adaptive immune cells and identify a distal transcribed enhancer that fine-tunes KRAS signaling in Tfh cells to support effective vaccine responses. These findings establish eRNAs as noncoding regulators of T cell circuits controlling antibody production and nominate the eKRAS-KRAS axis as a target to optimize humoral immunity. Funding Source N/A Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)

TIDEPOOL, a method for inferring disease trajectories across cohorts, identifies neutrophil-driven trajectories associated with severity of infections 2260680

Abstract Introduction Inferring molecular signatures of disease progression usually requires costly and time-consuming longitudinal samples. Single-cohort transcriptomic studies also suffer from the curse of dimensionality, as the number of genes profiled is much larger than the number of samples. The availability of numerous independent, heterogeneous datasets in public databases presents a unique opportunity to model disease progression trajectories by leveraging cross-sectional data that collectively capture all stages of a disease. Methods We introduce TIDEPOOL, a method that uses a disease-defining gene signature to define consensus disease trajectories within independent, heterogeneous datasets. Results To demonstrate the utility of TIDEPOOL, we applied it to 24 bulk transcriptomic datasets comprising 2,222 blood samples from patients with viral or bacterial infections of varying severities. We identified two diverging trajectories separating patients with severe outcomes from those with non-severe outcomes. We found 54 genes, clustered into four gene modules, that differentiate these two trajectories. We validated that these genes also differentiate patients with severe and non-severe outcomes in 1,913 samples of patients with infection from 10 external datasets (AUROC = 0.80). Through single-cell analysis of an integrated whole blood dataset, we identified that 3 of these gene modules were highly expressed in neutrophils and the other in B and dendritic cells. In-depth analysis of the 3 neutrophil-associated modules in the Single-Cell Atlas of Human Neutrophils (SCAHN) showed that the modules originate from different neutrophil subtypes including both protective and detrimental neutrophils. Conclusion Using the novel TIDEPOOL framework, we have identified a 54-gene signature that distinguishes infectious disease patients with severe and non-severe outcomes. Many of these genes originate from neutrophils, including multiple neutrophil subsets which are associated with both favorable and adverse outcomes. Funding Source n/a Topic Categories Computational and Systems Immunology (COMP)

IL-4Rα mediated signalling on Foxp3+ T regulatory cells has a protective role during cutaneous Leishmaniasis 2258800

Abstract Introduction Forkhead box P3 (Foxp3+) T regulatory (Treg) cells are a unique subset of CD4+ T cells that play important immunomodulatory roles, maintaining a balance between Type 1 and Type 2 immune responses. During L. major-induced cutaneous leishmaniasis, Treg cells accumulation at the site of infection has been implicated in suppressing a detrimental Type 2 immune response by modulating early interleukin (IL)-4 production; however, it remains unclear if IL-4Rα mediated signalling on Treg cells plays a significant role in this process. Methods To investigate this further, a BALB/c model was utilized in which IL-4Rα chain was selectively knocked down on Treg cells (Foxp3creIL-4Rα-/lox mice). Results Foxp3creIL-4Rα-/lox male mice, which had a greater degree of IL-4Rα knockdown on Foxp3+ Treg cells (≈ 102%), developed significant footpad swelling and ear swellings and increased parasitic burdens. The hypersusceptible phenotype observed in Foxp3creIL-4Rα-/lox BALB/c male mice was associated with an amplified Type 2 immune response and increased Treg cell recruitment. Flow cytometry analysis revealed that depletion of IL-4Rα on Foxp3+ Treg cells resulted in the induction of a L. major-induced Indoleamine 2,3 dioxygenase (IDO) mechanism that facilitated Leishmania replication. Conclusion Collectively, these data suggest a protective role for IL-4Rα mediated signalling on Treg cells in suppressing a detrimental Type 2 immune response during cutaneous Leishmaniasis. Funding Source National Research Foundation of South Africa Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

The RNA m6A reader protein YTHDF2 controls iNKT cell development and function 2308066

Abstract Introduction Invariant natural killer T (iNKT) cells are a unique subset of T lymphocytes that recognize glycolipid antigens presented by CD1d. As key liver-resident immune cells, they contribute to the pathogenesis of liver diseases such as autoimmune hepatitis. Understanding mechanisms regulating iNKT cell development and function may uncover therapeutic targets. N6-methyladenosine (m6A), the most abundant eukaryotic RNA modification, controls mRNA stability and translation, primarily via the m6A reader YTHDF2. While YTHDF2 is known to regulate immune cell functions, its role in iNKT cells and liver disease remains unclear. Methods We generated Ythdf2 conditional knockout (cKO) mice and assessed iNKT cell development in thymus, spleen, and liver by flow cytometry. Thymic iNKT cells from Ythdf2 cKO and controls underwent scRNA-seq. α-GalCer- and Con A-induced liver injury models were used to evaluate YTHDF2 function. Liver iNKT cells post-α-GalCer treatment were analyzed by bulk RNA-seq. Results Ythdf2 cKO mice showed markedly reduced iNKT cell numbers in thymus, liver, and spleen, with a significant loss of stage 3 thymic iNKT cells. YTHDF2 was dispensable for differentiation into NKT1, NKT2, and NKT17 subsets. scRNA-seq analysis identified transcription factor Bach2 as a potential YTHDF2 target during iNKT cell development. Loss of YTHDF2 in iNKT cells exacerbated α-GalCer- and Con A-induced acute liver injury. Ythdf2 cKO mice displayed elevated serum TNF-α levels compared to controls; however, TNF-α was mainly secreted by monocyte-derived macrophages rather than iNKT cells. Bulk RNA-seq of liver iNKT cells revealed that Csf1 (macrophage colony-stimulating factor), a key cytokine for macrophage differentiation, survival, migration, and function, is likely regulated by YTHDF2 in iNKT cells. Conclusion YTHDF2 is essential for iNKT cell development and modulates iNKT cell-mediated liver injury. Further studies are needed to define underlying mechanisms. Funding Source NIH Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)

Developing a Spiral Curriculum for Immunology in Undergraduate Medical Education: Lessons from Curricular Reforms in Azerbaijan 2259347

Abstract Introduction The goal of this study, conducted at the Medical Education Department of Azerbaijan Medical University, was to improve the quality and effectiveness of teaching in medical and health sciences through faculty development, curriculum innovation, competency-based education, and educational research. This was aligned with current changes and challenges in the world of educational technology and methodologies. The long-term goal is to prepare future healthcare professionals who are competent, compassionate, and socially responsible. Methods In this study, we applied competency-based education principles, developed new curricula aligned with WFME standards, trained faculty through WHO-supported programs, and introduced innovative assessment methods, including OSCE and OSPE. We also promoted educational research and interdisciplinary collaboration to improve the quality of teaching and learning. Results Assessing educational goals involved using structured frameworks, accreditation standards, and key performance indicators (KPIs). Frameworks guide competency evaluation, while standards like WFME and LCME ensure curriculum quality and institutional alignment. KPIs measure academic outcomes (e.g., exam scores, graduation rates), operational effectiveness (e.g., satisfaction, curriculum alignment), and strategic impact (e.g., community engagement). Evaluation models such as Kirkpatrick’s help track progress and support continuous improvement. The reports indicated a significant improvement and enhancement of our educational goals. Conclusion We conclude that the university should focus on advancing competency-based learning, integrating innovative technologies, and promoting interdisciplinary collaboration. Emphasis should be placed on equity, community health, and preparing students as leaders and change agents. Faculty development and learner well-being must also be prioritized. These goals align education with evolving healthcare needs and societal expectations. Funding Source n/a Topic Categories Immunology Education and Communication (EDU)

Polymorph‐Specific Electronic Transduction in WO ₃ during Molecular Sensing (Adv. Mater. 43/2026)

Roadmap of MCPyV T-antigens for off-the-shelf therapeutic MCC vaccine development 2309574

Abstract Introduction Merkel cell carcinoma (MCC) is a rare but extremely aggressive neuroendocrine skin cancer with a two-year mortality approaching 20% in patients with distant metastasis, representing a significant unmet clinical need. More than 80% of MCC cases are driven by Merkel cell polyomavirus (MCPyV), whose antigens are foreign to the immune system, highly immunogenic, and correlate with survival and response to immunotherapy. The uniform expression of its oncoprotein makes a virus-positive MCC (VP-MCC) an ideal target for antigen-specific immunotherapies. Methods We systematically defined MCPyV-derived epitopes presented by HLA-I molecules to identify suitable targets for development of a universal off-the-shelf vaccine. An integrated discovery pipeline was developed combining HLA-I pull-downs and LC—MS/MS-based detection using a panel of 95 monoallelic HLA lines, in silico antigen prediction, and literature curation. Immunogenicity of candidates was evaluated using VP-MCC patients and HLA-matched healthy PBMCs, with ELISpot assays as the primary readout. To enable functional validation, the MCPyV immunopeptidome was expanded to a dozen patient-derived VP-MCC cell lines, providing a platform to examine T cell targeting. Results This approach enabled the identification of MCPyV-derived epitopes presented across diverse HLA-I alleles, including conserved and promiscuous peptides with measurable T cell reactivity in both patients and healthy donors. Expansion of the MCPyV immunopeptidome across patient-derived MCC models supported downstream functional evaluation of antigen-specific T cell responses in physiologically relevant tumor contexts. Conclusion Our findings define a roadmap for MCPyV antigen selection and support the feasibility of developing an off-the-shelf therapeutic vaccine for VP-MCC. More broadly, this systematic framework for epitope discovery and validation may be broadly applicable to immunotherapy development in other virally driven cancers. Funding Source NIH, SNSF Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

Hematopoietic origins of an early wave of CD8+ T cells 2256072

Abstract Introduction CD8+ T cells produced in early life exhibit distinct phenotypic and functional characteristics compared to those generated in adulthood. In neonates, CD8+ T cells have a propensity to differentiate into virtual memory (VM) cells, which allows for rapid, innate-effector responses to immune challenges. However, the mechanisms that bias neonatal CD8+ T cells towards a more innate-like lineage remains poorly understood. Methods We hypothesized that innate-like programming of CD8+ T cells in early life could be due to changes in thymic selection, TCR usage, thymic environment or production from alternative hematopoietic progenitors. To determine how each factor contributes to changes in CD8+ T development at various stages of life, we used a multitude of cellular approaches (flow cytometry, intrathymic injections, artificial thymic organoids) and sequencing assays (paired single cell TCR/RNA sequencing, methyl-seq) with thymocytes from different aged mice. Results We identified a distinct wave of CD8+ thymocytes with high Eomes expression in the neonatal thymus that was absent in adults. Single-cell RNA/TCR sequencing showed these Eomes+ cells formed a unique cluster with effector-like gene signatures and TCRs enriched for germline-encoded features. Intrathymic injections of fetal progenitors showed that CD8 thymocytes maintained Eomes expression even in an adult thymic environment. Lin28b expression in adult thymocytes cell-autonomously induced Eomes. Finally, multiple fetal progenitor populations, but not adult HSCs, generated VM cells, which corresponded to developmental-related changes Lin28b expression (master regulator of lymphopoiesis) and methylation of innate genes. Conclusion Our findings demonstrate that the bias for VM T cell development in early life is intrinsically programmed within fetal hematopoietic progenitors. This program is established during a specific developmental window and is driven by Eomes, which is sufficient to cell-autonomously promote the innate-like T cell fate. Funding Source NIH R21 Topic Categories Hematopoiesis and Immune System Development (HEM)