Browse Articles

Immunophenotypic Analysis of Alopecia Areata Progression in a C3H/HeJ Mouse Model 2258053

Abstract Introduction Alopecia areata is a complex polygenic autoimmune disorder that affects approximately 160 million individuals worldwide, manifesting primarily as non-scarring, patchy hair loss. Current treatments utilizing JAK inhibitors necessitate prolonged use and are often accompanied by adverse side effects, such as increased headaches and a heightened risk of respiratory infections. Expanding therapeutic treatment options relies on a better understanding of the autoinflammatory mechanisms initiating and perpetuating alopecia areata. The C3H/HeJ inbred mouse strain is a well-established model for studying the pathogenesis of alopecia areata and validating experimental treatments. However, detailed knowledge of how the cellular immunophenotype in the skin changes during the stages of alopecia areata progression in C3H/HeJ mice is incomplete. Methods We performed immunofluorescence microscopy and flow cytometry to assess the prevalence of macrophages, dendritic cells, B cells, CD4 T helper cells, CD8 T cells and T cells around the hair follicle and surrounding dermis tissue at various stages of disease progression. Cell populations were quantified globally in the skin and per hair follicle. Results Findings indicate distinct immunophenotypic phases of alopecia areata. We defined these stages as: control with no signs of disease, prelesional disease, active disease, established disease, and regrowth. We have carefully immunoprofiled the skin and hair follicles in each of these stages to create an immune blueprint for mapping alopecia areata in natural disease of C3H/HeJ mice. Conclusion Chronologically ordering hair follicle attack pathogenesis may reveal therapeutic targeting of inflammation pathways causing alopecia areata in humans. Funding Source National Alopecia Areata Foundation, NIH training grant 5T34GM136481,COMPASS training grant EDUC5-13667, Jameson Lab funds Topic Categories Basic Autoimmunity (BA)

Identification and Characterization of Hematopoietic Stem and Progenitor Populations from Cord Blood-Derived CD34+ Cells 2306499

Abstract Introduction Hematopoietic stem and progenitor cells (HSPCs) are essential for blood cell development and immune system function. Accurate identification and phenotypic characterization of these populations are critical for understanding hematopoiesis and optimizing stem cell-based therapies. CD34+ cells derived from cord blood represent a rich source of HSPCs. Here, we used standardized protocols for thawing, staining, and short-term culture of CD34+ cells, followed by multiparametric flow cytometric analysis using CytoFLEX mosaic 88 Spectral Detection Module to delineate stem and progenitor subsets. Methods Multiparametric flow cytometric analysis was performed using the CytoFLEX mosaic 88 Spectral Detection Module to identify hematopoietic stem cells (HSCs) and progenitor subsets, including multipotent progenitors (MPP), common myeloid progenitors (CMP), granulocyte-monocyte progenitors (GMP), and megakaryocyte-erythroid progenitors (MEP). Subsets were defined based on established immunophenotypic marker combinations. Comparative analysis was conducted across three platforms: CytoFLEX SRT, CytoFLEX LX, and CytoFLEX mosaic 88 Spectral Detection Module. Results The gating strategy enabled clear discrimination of HSCs (CD34+CD38⁻CD90+CD45RA⁻) and downstream progenitor populations across all CytoFLEX platforms. Resolution of these populations, assessed by staining index (SI), demonstrated the highest SI values with the CytoFLEX mosaic 88 Spectral Detection Module, indicating superior performance in resolving rare subsets. Conclusion This protocol provides a robust approach for immunophenotyping cord blood-derived CD34+ cells, enabling precise identification of HSPC subsets by flow cytometry. The ability to analyze and sort these populations supports downstream applications in stem cell research, transplantation biology, and regenerative medicine. Funding Source n/a Topic Categories Hematopoiesis and Immune System Development (HEM)

Field‐Programmable Mobile Magneto‐Photonic Metaparticles for Active Light Manipulation and Steering

ABSTRACT Controlling the flow of light within complex and dynamic environments is essential for a wide range of applications, from deep‐tissue imaging and optogenetics to precision phototherapy. Typically, such light flows are controlled using external optical systems requiring line‐of‐sight access or by embedded nanoparticle scatterers with limited directional control, underscoring the need for mobile photonic agents capable of actively delivering and steering light within complex media. Here, we present magneto‐photonic metaparticles: mobile, magnetically actuated microstructures that integrate a magnetic core with a nanoimprinted photonic surface. This hybrid design merges the reconfigurability of photonic metasurfaces with the mobility of magnetic actuation, enabling programmable translation, rotation, and real time beam steering in aqueous media. In a proof‐of‐concept demonstration, we realize polymeric metaparticles with an embedded magnetic core and a nanoimprinted surface that exhibit controlled locomotion and active, magnetically programmable beam steering. Our design approach further points to more sophisticated metaparticle designs with high‐efficiency, polarization‐insensitive light steering, compatible with a scalable, single‐step nanoimprint process. The mobile magneto‐photonic metaparticle platform combines metasurface‐level optical control with magnetic mobility, offering a versatile and scalable approach for active photonic control in complex environments.

Epigenetic silencing of miR-141 via core promoter methylation is associated with short-term bladder cancer progression

PAPR reduction in NOMA waveforms using PTS-based binary–real coded genetic algorithm for 6G radio systems

Macrophage Plasticity Drives Cardiac Dysfunction in Hypertension 2253031

Abstract Introduction Chronic immune activation is a central driver of cardiovascular remodeling in hypertension (HTN), which affects ∼50% of American adults and predisposes them to heart failure. Fibrosis is a hallmark of this transition, yet the initiating immune mechanisms during the development of HTN remain poorly understood. Here, we identify a previously unrecognized macrophage fate trajectory, Macrophage-to-Myofibroblast Transition (MMT), as a key immunological mechanism linking hemodynamic stress to fibrosis in hypertensive hearts. Methods In our study, HTN was induced using the unilateral nephrectomy + aldosterone infusion + high-salt intake model for 14 days. Cardiac function was assessed via ultrasound (parasternal short-axis and apical four-chamber views) and direct left ventricular catheterization. Hearts were harvested for flow cytometry and histopathology, while mechanistic in vitro studies were conducted using RAW264.7 cells and bone marrow—derived macrophages to elucidate drivers of MMT. Results Radiotelemetry confirmed HTN in our mouse model. Despite preserved ejection fraction, direct ventricle analysis revealed impaired relaxation consistent with diastolic dysfunction. Trichrome and Sirius red staining showed profound cardiac fibrosis, and flow cytometry and fluorescence microscopy revealed a striking increase of CD68+αSMA+ MMT cells. Notably, the magnitude of this MMT population rivaled that of dedicated myofibroblasts (CD68-αSMA+) in the hearts of hypertensive mice. In vitro, IL4 and IL10 induced macrophage acquisition of αSMA and myofibroblast-like morphology, identifying these cytokines as critical mediators of MMT. Conclusion This study provides the first evidence of MMT in HTN prior to heart failure, revealing a cytokine-dependent macrophage plasticity that drives early fibrotic remodeling and impairs diastolic function. Targeting IL4/IL10-mediated macrophage reprogramming may represent a novel immunomodulatory strategy to prevent fibroinflammatory progression in hypertensive heart disease. Funding Source NIH RO1-HL146713; NIH R25-GM083247; AHA 23TPA1076467. PI-sponsored student. Topic Categories Immune Mechanisms of Human Disease (HUM)

Co-adjuvants of IFN-γ and a TLR agonist delivered by lipid-PLGA hybrid nanoparticles enhanced the efficacy of an oxycodone vaccine 2308279

Abstract Introduction Oxycodone misuse contributes to opioid use disorder and overdose. Immunopharmacotherapy offers a promising strategy by eliciting oxycodone-specific antibodies that sequester the drug in the bloodstream and reduce its entry into the central nervous system. Enhancing vaccine efficacy through optimized adjuvant selection and delivery platforms is key to achieving robust and protective immune responses. Methods Oxycodone hapten—sKLH vaccines were formulated as conventional conjugates or as lipid—PLGA hybrid nanoparticles (hNPs) incorporating IFN-γ alone or with TLR agonists (poly I:C or R848). The OXY—sKLH antigen was conjugated to hNPs via thiol—maleimide chemistry. Female BALB/c mice (n = 8/group) received subcutaneous immunizations on Days 0, 14, and 28. Anti-oxycodone IgG titers, subclasses, and affinity were assessed. On Day 42, mice received 2.5 mg/kg oxycodone subcutaneously. Serum and brain samples were collected 30 minutes later for pharmacokinetic analysis. Antinociception was evaluated using a 55 ± 1 °C hot plate test. Results All adjuvanted vaccines elicited strong anti-oxycodone IgG. hNP-based vaccines co-adjuvanted with IFN-γ and poly I:C or R848 generated the highest anti-oxycodone titers and strongest affinity (lowest IC50) compared to conjugate vaccines. Immune responses toward hNP-based vaccines were IgG1-dominant, with modest IgG2a in dual-adjuvant groups. Post-challenge, vaccinated mice showed higher serum and lower brain oxycodone levels, with the IFN-γ+R848 hNP-based vaccine group showing the lowest brain concentrations. All vaccines reduced oxycodone-induced antinociception, with the IFN-γ+poly I:C hNP-based vaccine yielding the greatest effect. Conclusion Co-delivery of IFN-γ with a TLR agonist in a lipid—PLGA hNP-based vaccine platform enhances both the magnitude and functional quality of anti-oxycodone antibodies, supporting this co-adjuvant nanovaccine strategy for opioid use disorder. Funding Source National Institutes of Health (NIH) / National Institute on Drug Abuse (NIDA) award 5UG3DA048775-02, PIs: C. Zhang and M. Pravetoni Topic Categories Vaccines and Immunotherapy (VAC)

Constant engagement of a natural killer (NK) cell activation receptor with self-MHC-I renders hyporesponsive NK cells 2330663

Abstract Introduction Activating NK cell receptors are critical for controlling acute murine cytomegalovirus (MCMV) infection, most clearly demonstrated in C57BL/6 mice, where resistance is mediated by the Ly49H receptor through recognition of the viral ligand m157 expressed on infected cells. NK cell—dependent resistance to MCMV is also observed in Ly49H-deficient strains, such as MA/My, where Ly49P and Ly49R can recognize MCMV-infected cells in a class I MHC—dependent manner in vitro. However, the role of these receptors in vivo has not been explored. In addition, these activating receptors may engage self—MHC class I ligands in vivo, yet the physiological relevance of this interaction remains poorly defined. Methods To selectively assess Ly49P function in vivo, we generated Ly49- and MHC class I—deficient mice expressing a single Ly49P receptor on NK cells by knocking in Ly49P cDNA into the Ncr1 locus. Founder mice were then subsequently crossed onto distinct MHC class I backgrounds. Results NK cells from Ly49P-KkDk or Ly49P-KdDd mice exhibited reduced surface expression of Ly49P compared with Ly49P-KbDb mice, suggesting MHC class I—dependent masking of Ly49P. Consistently, Ly49P-KkDk NK cells showed diminished degranulation and IFN-γ production compared with controls following anti-Ly49P or NK1.1 stimulation, indicating a generalized hyporesponsive state to ITAM-associated signaling. This anergic state appeared to be regulated at the level of proximal signaling, as NK cell responsiveness was restored by PMA/ionomycin stimulation, which bypasses early signaling events. Notably, disruption of Ly49P—MHC class I cis interactions by citric acid treatment restored responsiveness of hyporesponsive NK cells to both Ly49P and NK1.1 crosslinking. Conclusion Thus, sustained stimulation of a self-specific activating receptor in vivo induces a hyporesponsive state to stimulation through both cognate and unrelated activating receptors. Funding Source NIH Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Novel CrkL Adaptor Protein Inhibitors Suppress Tumor Growth and Reverse NK Cell Exhaustion 2257879

Abstract Introduction Crk adaptor proteins (CrkI/II and CrkL) integrate oncogenic and immune signals. Phosphorylated CrkL (pCrkL, Y207) enforces an autoinhibited state linked to metastasis and NK/T‑cell dysfunction. We posited that blocking CrkL phosphorylation could suppress triple‑negative breast cancer (TNBC) while sparing normal immunity. Methods We screened >2,000 compounds across five libraries with an AlphaScreen assay for CrkL Y207 phosphorylation. Hits were triaged by thermal shift, in‑vitro kinase, and single‑molecule FRET. Cell assays used TNBC lines and human PBMCs (proliferation, phospho‑flow/Western, apoptosis). Orthotopic and PDX TNBC models assessed in‑vivo efficacy and tolerability with daily oral dosing. Results Seventy‑one primary hits were refined to two natural products, NC5 and NC11, that bind CrkL. smFRET showed NC5 counters Abl‑driven CrkL phosphorylation, shifting to an open, low‑FRET state. NC5 reduced TNBC proliferation (IC50 ∼1.3—3.6 µM) while sparing PBMCs (IC50 >18 µM) and increased Annexin V+ apoptosis. Pathway readouts in TNBC showed ↓pCrkL and ↓pERK1/2 with ↑pJNK and ↑BIM, with minimal PBMC effects. In vivo, low‑dose NC5 (5 mg/kg/day, p.o.) suppressed tumor growth and prolonged survival versus vehicle and imatinib (MDA‑MB‑231 median 41 vs 25 and 28 days; PDX 53 vs 39 days). Serum chemistries remained within reference ranges, indicating favorable tolerability. Conclusion Targeting CrkL phosphorylation with the natural product NC5 delivers dual benefits: direct TNBC suppression and reinvigorates anti-tumor immunity. These data indicate NC5 as a first‑in‑class pCrkL inhibitor and support further development, including combination strategies and IND‑enabling studies. Funding Source R01AI130197 Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)

The Role of Recirculating Thymic T regulatory cells in Central Tolerance and Immune Homeostasis 2261236

Abstract Introduction AIRE+ medullary thymic epithelial cells (mTECs) play a critical role in establishing immune tolerance. These cells peak 2-3 weeks after birth and then steadily decline as mice get older. The mechanism by which AIRE+ mTECs decline remains unclear. We observed that accumulation of recirculating thymic T regulatory cells (RT-Tregs) coincides with a decline in AIRE+ mTECs. Using scRNA-seq, we found that RT-Tregs may have cytotoxic potential. We studied the effect of RT-Tregs on AIRE+ mTEC abundance by selectively depleting RT-Tregs. Methods Thymi samples of RagGFP x Foxp3RFP mouse at age 1, 2, 3, 4, 8, and 12 weeks (n = 4) were analyzed using flow cytometry. Single-cell RNA-seq analysis was performed on CD73+ thymocytes in 8-9-week-old mice. Ultrasound-guided intrathymic injection of 0.05 μg diphtheria toxin (DT) or PBS was performed on 5-week-old Foxp3-DTR mice (n = 8) every other day for 1.5-4.5 weeks and AIRE+ mTECs were quantified using flow cytometry. Results scRNA-seq analysis revealed different clusters within RT-Tregs, such as effector Treg subset including GzmB+ cells. RT-Tregs accumulate in the thymus after birth and reach up to 26.1% of the Treg compartment by 4 weeks of age, and 73.9% by 12 weeks of age. Upon intrathymic DT injection, RT-Treg population was reduced significantly (>50%) but de novo and splenic Tregs were preserved. RT-Treg depletion resulted in a significant increase (p = 0.008) in the number of AIRE+ mTECs. Conclusion We show that RT-Tregs are a diverse subset that includes effector-like cells. When RT-Treg number increases, AIRE+ mTEC decreases, and vice versa. Using previously published datasets, we observed that TCR diversity of conventional T cells (Tconv) in lymphoid organs of AIRE-/- mice was significantly increased relative to WT mice. We hypothesize that early in life AIRE+ mTECs promote self-tolerance. Once the peripheral tolerance has been established, RT-Tregs eliminate AIRE+ mTECs, resulting in a more diverse TCR repertoire that is more pathogen-reactive. Funding Source n/a Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)

Exposure to short chain fatty acids in early-life leaves a life-long epigenetic imprint on hematopoietic stem and progenitor cells 2328904

Abstract Introduction Early life is a critical window during which the gut microbiota sculpts immunity and long-term susceptibility to allergic disease. Methods Using neonatal antibiotic administration and bone marrow transplantation assays, we show that depletion of short chain fatty acid (SCFA)-producing bacteria alters gene expression in hematopoietic stem and progenitor cells (HSPCs) and imprints a persistent, transplantable atopic immune phenotype. Results Bone marrow transplants from exposed mice generate recipients with elevated serum IgE, downstream increased IgE bound to basophils, and exacerbated allergic lung inflammation following papain challenge. H3K27 ChIP-seq analyses further reveals differential histone acetylation in HSPCs, consistent with a SCFA-mediated epigenetic regulatory mechanism. Conclusion Collectively, these findings establish a link between gut microbiota composition, hematopoiesis, and long-term immune function, offering a mechanistic explanation for microbiota-driven susceptibility to atopic disease and hematopoietic dysfunction. Funding Source CIHR Topic Categories Mucosal and Regional Immunology (MUC)

Platelet Origin TGFβ Mediates Immunosuppressive Effects in Monocyte Derived Dendritic Cells in People Living With HIV 2258077

Abstract Introduction People living with HIV (PLWH) exhibit increased platelet activation and formation of platelet monocyte complexes (PMCs). in vitro PMC derived dendritic cells (PMDCs) exhibit an immunosuppressive phenotype via decreased antigen uptake and reduced T cell stimulation. TGFβ and β2M have been shown to polarize monocytes to pro-reparative/pro-inflammatory states, respectively, in a dose dependent manner during vascular events. This study investigates the role of platelet derived TGFβ and β2M in modulating the immunogenicity of PMDCs in PLWH. Methods Monocytes and platelets were isolated from PLWH and people without HIV (PWOH). TGFβ and β2M secreted by platelets was quantified by ELISA and monocytes were either treated directly with TGFβ/β2M or co-cultured with collagen activated autologous platelets with or without TGFβ/β2M inhibitors. Monocytes were then differentiated into immature (iDC) and ψHIV-pulsed mature DCs (mDC). Cellular functions were measured via ELISA and flow cytometry. Results Platelets from PLWH secreted higher levels of TGFβ than PWOH with or without activation. High dose TGFβ treated monocytes exhibited decreased functional surface marker expression such as CD84 and CD14 at both monocyte and iDC stages, secretion of proinflammatory TNFα in iDCs, and immunostimulatory CD163 at both iDC and mDC stages when compared to untreated monocytes. Inhibiting TGFβ at the platelet stage reversed these effects. Further, it also reduced the levels of TGFβ intrinsically produced by PMDCs. Conclusion These results suggest that platelet-derived TGFβ is a factor in inducing immunosuppressive phenotypes in PMDCs, especially in PLWH as they exhibit increased PMCs and platelet-origin TGFβ, compared to PWOH. Inhibition of platelet-monocyte interactions or suppressing platelet-origin TGFβ may improve endogenous antiviral responses in PLWH. Using platelet-free monocytes can potentially improve the immunogenicity of DC-based vaccine therapies where monocytes serve as a predominant source for autologous DCs. Funding Source R21AI162076, NIHT32AI007285 Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Increased CaMK4 Activity Drives Excessive CD8+ T-Cell Cytotoxicity in Systemic Lupus Erythematosus 2306645

Abstract Introduction Calcium/calmodulin-dependent kinase IV (CaMK4) modulates key immune pathways central to the development and amplification lupus pathology, including IL-2 suppression, elevated IL-17, Treg—Th17 imbalance, and Tfh-driven B-cell responses in lupus patients and lupus prone mice. However, its role in regulating cytotoxic CD8+ T-cell activity in lupus remains unclear, prompting our aim to define how CaMK4 shapes CD8+ effector functions and contributes to disease progression. Methods CD8+ T cells from SLE patients, MRL/lpr mice, and Camk4⁻/⁻ mice were analysed for cytotoxic markers by flow cytometry. CaMK4 was inhibited genetically or pharmacologically, and cytotoxicity was assessed by degranulation, killing, and cytokine assays. Results Analysis of CD8+ T cells from the peripheral blood of patients with SLE revealed an elevateion of CaMK4 expression compared with healthy controls. In MRL/lpr mice, CD8+ T cells isolated from kidneys of older, clinically affected animals, exhibited increased CaMK4 levels relative to younger, presymptomatic mice or splenocytes, suggesting a disease and tissue-associated upregulation. Consistent with these observations, injection of an anti-glomerular basement membrane (GBM) into B6 normal mice induced a similar pattern of increased CaMK4 expression in renal CD8+ T cells including those from kidney draining lymph nodes. Functional studies comparing CD8+ T cells from Camk4⁻/⁻ and B6 mice showed a notable reduction cytotoxic molecules and killing capacity in the absence of CaMK4. Furthermore, pharmacologic inhibition using KN-93 significantly reduced phosphorylated (p)CaMK4, the active kinase form, resulting in a parallel decrease in cytotoxic cytokines such as IFNg, GZMB and Perforin. Conclusion These findings reveal that increased CaMK4 expression in CD8+ T cells accounts for enhanced cytotoxicity in lupus, and that its blockade reduces pathogenic effector functions. Our studies reveal a previously unrecognised regulatory pathway governing CD8+ T-cell activity in lupus. Funding Source n/a Topic Categories Basic Autoimmunity (BA)

Conductive Polymer Bridges Mediate High‐Performance Flexible Perovskite–Organic Tandem Solar Cells

ABSTRACT In flexible perovskite–organic tandem solar cells (TSCs), the numerous grain boundaries (GBs) in Br‐rich perovskite films are critical in determining their efficiency and mechanical durability. Exacerbated carrier recombination, photon‐induced lattice expansion, and phase segregation originating from GBs substantially reduce the photovoltaic performance and reliability. In this work, we developed a conductive polymer composite by incorporating an ionic liquid into polyurethane (PU), which passivates Pb‐ and FA‐related defects and suppresses halide segregation while mitigating residual stress. Critically, it establishes efficient lateral conductive polymer bridges (CPB) across GBs. The CPB significantly increased carrier diffusion length and suppressed nonradiative recombination. As a result, the rigid wide‐bandgap (WBG) perovskite solar cells (PSCs) achieved a champion efficiency of 20.85% along with outstanding operational stability ( T 90 > 1000 h). In flexible configurations, CPB‐mediated devices attained a high efficiency of 19.03% and exhibited excellent mechanical robustness, retaining 92% of their initial PCE after 10 000 bending cycles. Furthermore, the perovskite–organic TSCs reached notable power conversion efficiencies of 25.92% for rigid versions and 24.02% for flexible ones. Remarkably, the rigid tandem cells maintained 87% of their initial PCE after 1000 h of continuous light exposure, while the flexible counterparts retained 81% of their original PCE after 10 000 bending cycles.

High‐Efficiency Asymmetric Spin Transport Enabled by Nanocolumn Molecular Semiconductors

ABSTRACT Owing to weak spin‐orbit coupling, molecular semiconductors are among the few materials supporting room‐temperature spin functionality, yet their low spin‐transport efficiency ( η s , ∼5%) limits applications. Here, we report molecular spintronic devices featuring vertically asymmetric nanocolumn channels formed by phase separation. These channels confine spins and generate built‐in electric fields, boosting room‐temperature η s to 20%—the highest value reported to date, over five times that of unstructured films. Simultaneously, the nanocolumn channels induce pronounced bias‐dependent asymmetry, with η s of 20% at +0.2 V versus 1% at −0.2 V, yielding a record asymmetry factor, significantly outperforming other material systems (e.g., metal oxides, 2D materials, conventional molecular/inorganic semiconductors). This dual achievement of record‐high efficiency and strong asymmetry establishes a platform for new spintronic functionalities. As a proof of concept, we demonstrate its potential for information‐secure applications via spin‐signal encryption elements and two‐stage spin true random number generators, integrating structural design with spintronic operation.

Correction: Abstract 5588 Multifunctional carbon dots nanocarriers: Dual-drug delivery via π-π stacking interaction for stimuli-responsive chemotherapy and high oxidative stress

Multimodal artificial intelligence predicts postoperative complications following complex brain tumor surgery in an international multicenter retrospective cohort

Host-Parasite Interactions of Intraerythrocytic Malaria Infections 2260817

Abstract Introduction Malaria infections debilitate communities every year, with the highest fatality rates occurring in children. Plasmodium parasites have complicated host immune evasion tactics that remain poorly understood and contribute to the difficulties in treating this disease. At the asexual replication stage of its life cycle, the parasite is known to regulate the plasma membrane of its host red blood cell (iRBC) to prevent a loss of membrane asymmetry, which would reveal apoptosis signals like phosphatidylserine (PS) and prompt phagocytic clearance via interactions with PS receptors, such as CD36. However, how the parasite maintains membrane asymmetry to evade detection is unknown. Methods To study the interaction of iRBCs with host phagocytes we developed a flow cytometry-based assay using the pH-sensitive fluorophore pHrodo. Using this system, we show that CD36-/- macrophages phagocytose iRBCs at a lower rate than wildtype macrophages. Further studies utilizing LysMCreCD36flox mice identified that mice lacking CD36 expression on monocytes and macrophages had significantly higher parasitemia within 4 days of infection. These data suggest that CD36 is critical for early control of malaria infections. Results Published data suggest that parasites can transport phospholipids to the iRBC membrane, so we hypothesized that this process may be critical for preserving membrane asymmetry of the iRBC. Given that the apicoplast organelle of Plasmodium parasites is the site of fatty acid synthesis, we employed apicoplast-deficient parasites to investigate if disrupting phospholipid metabolism would result in a loss of membrane asymmetry. We identified that apicoplast-deficient parasites have an increased externalization of PS, supporting the hypothesis that membrane asymmetry is regulated in part by the apicoplast organelle. Conclusion Our data suggest that targeting the apicoplast therapeutically could improve the ability of the immune system to clear iRBCs by impairing the immune evasion abilities of the parasite. Funding Source N/A Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)

AAI-Recommended Immunology Content Learning Objectives for Undergraduate Medical Education in the U.S.A 2223333

Abstract Introduction The Medical Immunology Curriculum Task Force, sponsored by the AAI Education Committee, formed in late 2023 to study and establish AAI-endorsed recommendations for the immunology taught in U.S. medical schools. Methods An initial research survey was developed asking medical educators to report structural data about when and how immunology is taught, and what major themes are taught in their respective institutions. The results from that survey were presented at Immunology 2025 alongside a dedicated workshop session to further iterate recommended content coverage. The Task Force then developed foundational topics, learning objectives (LOs), and associated clinical correlations based on survey 1 and workshop feedback in 2025. A second survey about the topics and LOs was distributed to representatives of all medical schools in the USA with enrolled students in September 2025. Results This presentation will provide the key highlights about the structure and analysis of results of the second survey, with the goal of developing further community-based responses. Feedback will be incorporated into a final recommendation submitted to AAI Council and for peer review. Conclusion Audience members will have the opportunity to provide feedback at the meeting (via QR code) as well as implement the content recommendations as they see fit. Any participant — past via survey and at the meeting — will have the opportunity for acknowledgment in the final publication of the AAI Medical Immunology Content Recommendations. Funding Source n/a Topic Categories Immunology Education and Communication (EDU)

Comparison of transcriptional signatures in human and non-human primates during malaria sporozoite vaccination with concurrent chemoprophylaxis 2330945

Abstract Introduction Developing a highly effective, durable malaria vaccine remains a global health priority. A promising approach is the chemo-attenuated, live whole sporozoite (SPZ) vaccine, in which SPZ is co-administered with an antimalarial agent, often chloroquine, that kills liver-emerging parasites to abrogate blood-stage progression while allowing effective immune responses against late liver-stage antigens. In malaria-naive adults, this approach using Plasmodium falciparum SPZ (PfSPZ-CVac) confers complete, sterile protection against subsequent challenge with controlled human malaria infection (CHMI), but trials conducted in malaria-exposed adults have shown reduced vaccine efficacy. Studies in mice and non-human primates (NHP) have revealed that long-lived, liver-resident memory T cells are critical to protection conferred by whole-sporozoite vaccination. However, immune correlates of protection in the more accessible peripheral blood compartment remain unknown. Methods Here, we identified whole-blood transcriptional signatures that are associated with a protective chemo-attenuated, SPZ vaccine regimen in both NHP and malaria-naïve adults enrolled in a clinical trial (PMID 34048504). Comparative analyses of protective signatures across distinct cell types using single-cell RNA-seq of liver and blood lymphocytes from NHP are ongoing. Results Natural killer (NK) cell signatures were significantly enriched in those receiving the protective regimen at early immunization time points and post-challenge in both NHP and humans. In NHP, this signature was reflected in both the liver and blood, with liver-resident CD16+ and CD16- NK cells correlating positively and negatively with protection respectively. Conclusion Our findings suggest that early innate immune activation, particularly NK cells, is conducive to functional adaptive immunity. Funding Source National Institutes of Health Topic Categories Vaccines and Immunotherapy (VAC)