Allergy

Asthma severity and immune responses are regulated by circadian rhythms, yet the role of circadian timing in fungal allergen-induced airway inflammation remains poorly defined. Alternaria alternata, a clinically relevant fungal allergen, is strongly associated with severe asthma exacerbations and persistent airway dysfunction. Using a preclinical mouse model, we investigated whether pulmonary responses to Alternaria exposure are influenced by time of day and sex. We demonstrate that Alternaria induces allergic airway inflammation, airway hyperresponsiveness (AHR), and epithelial barrier disruption in a circadian- and sex-dependent manner. Female mice exhibited enhanced eosinophilic, neutrophilic, interstitial macrophage, and dendritic cell infiltration predominantly at Zeitgeber Time 0 (ZT0), whereas males showed stronger inflammatory responses at ZT12. Alternaria exposure increased IL-33 release and promoted ILC2 and Th2 cell accumulation, with distinct temporal patterns between sexes. Cytokine and chemokine profiling revealed robust Th2, proinflammatory, and Th17 responses that varied with exposure time, with higher responses at ZT12 in females and ZT0 in males. Markers of tissue injury, including lactate dehydrogenase and uric acid, followed similar circadian-dependent trends. Functionally, Alternaria-exposed mice displayed greater AHR during the resting phase, particularly in males. Additionally, Alternaria disrupted epithelial junctional proteins (E-cadherin and ZO-1) and altered expression of core circadian clock proteins CLOCK, BMAL1, and REV-ERB. Mechanistically, peak inflammation coincided with enhanced STAT1, STAT3, and STAT6 activation. Collectively, these findings identify circadian timing and sex as key determinants of fungal allergen-induced airway inflammation and suggest chronotherapeutic approaches may improve asthma outcomes.

Introduction: Mast cells are central effectors of IgE-mediated allergic responses and reside in barrier tissues, where they encounter diverse environmental compounds. How naturally occurring bioactive compounds influence mast cell function under resting versus allergic conditions remains poorly defined. Methods: We compared the effects of cholera toxin, aconitine, and sennoside A on viability, degranulation, and cytokine production in murine bone marrow-derived mast cells. We then examined the acute physiological effects of oral sennoside A in an ovalbumin-induced mouse model of food allergy. Results: None of the compounds reduced mast cell viability at the concentrations tested. Sennoside A, but not cholera toxin or aconitine, induced modest degranulation in resting mast cells without increasing TNF- or IL-6 secretion. In contrast, sennoside A markedly suppressed IgE-dependent antigen-induced degranulation, TNF- and IL-6 secretion, and Il1b expression. Acute oral sennoside A induced dose-dependent diarrhea and hypothermia and increased colonic Tnfa, Il1b, Il33, and Hdc expression. In allergic mice, sennoside A attenuated allergen-induced hypothermia, reduced duodenal Tpsab1 expression, and decreased circulating total IgE, OVA-specific IgE, and OVA-specific IgG1, while increasing Il5 expression. Conclusion: Sennoside A differentially regulates mast cell responses according to activation state and attenuates features of experimental food allergy. These findings identify a previously unrecognized immunomodulatory effect of sennoside A on IgE-driven mast cell activation. However, the mechanisms and the contribution of mast cells to the in vivo phenotype remain to be defined.

Background: Moderate-to-severe asthma affects 15-30% of asthma patients, but accounts for over 50% of healthcare costs and disproportionate morbidity. However, the genetic mechanisms underlying moderate-to-severe versus mild asthma remain poorly understood. Methods: We performed separate pooled multi-ancestry GWAS of mild (N = 14,372) and moderate-to-severe asthma (N = 7,096) versus non-asthma controls (N = 28,816) among adult participants in the NIH All of Us Research Program (version 8). European, African, and Latino/admixed ancestry-specific GWAS were combined using fixed-effect meta-analysis. Lung expression quantitative trait loci (eQTL) and pathway analyses were performed to identify candidate genes and biological pathways across asthma phenotypes. Results: Mild and moderate-to-severe asthma shared susceptibility loci at IL1RL1, IKZF3, and the GTF3AP1-IL33, GTF3AP1-RANBP6, LINC02757-EMSY and HLA-DRB1-HLA-DQA1 regions. Shared lung eQTLs implicated IL18R1, IL18RAP, HLA genes, IL33, LRRC32, GRB7, MIEN1 and GSDMB. In contrast, the phenotypes exhibited distinct genetic architectures. Mild asthma was characterized by broader HLA class II signals and associations at SMAD3 and GSDMB, with enrichment of antigen presentation, T-helper cell differentiation, and TGF-{beta} regulation, consistent with adaptive immune mechanisms. Moderate-to-severe asthma was characterized by WDR36 and PTCH1, with lung eQTLs implicating TSLP, CAMK4, and FANCC. Pathway analysis identified enrichment of IL-13, IL-6, and IL-10 production, myeloid leukocyte differentiation, and oxidative stress responses, consistent with innate inflammation and pathways implicated in steroid resistance. The IL33 signals showed a severity-gradient effect, with stronger associations in moderate-to-severe asthma. Conclusion: Mild and moderate-to-severe asthma exhibit shared and distinct genetic architectures that support existing biologic targets and suggest novel therapeutic candidates.

Background. Polygenic risk scores (PRS) capture inherited susceptibility to asthma, whereas methylation risk scores (MRS) may reflect disease-associated epigenetic variation. We assessed whether these scores differ in patients requiring biologic therapy and whether MRS change after mepolizumab initiation. Methods. Cross-sectional analyses in the GEMAS study included 699 participants with genotype data (428 with asthma, 271 controls) and 668 with blood DNA methylation data (408 with asthma, 260 controls). We evaluated 35 existing asthma PRS and derived six MRS from published epigenomic asthma studies. Longitudinal MRS changes after mepolizumab initiation were assessed in 16 GEMAS patients and were replicated in 20 patients from the MEGA study. Results. Twenty-eight PRS differentiated biologic-treated patients from controls (areas under the curve [AUC], 0.68-0.75), but none distinguished biologic-treated and non-treated patients after multiple-testing correction. MRS was higher in asthma without biologic than in controls (odds ratio [OR], 1.64; 95% CI, 1.34-1.99) and lower in biologic-treated than in asthma without biologic patients (OR, 0.54; 95% CI, 0.35-0.81). MRS did not differ significantly between biologic-treated patients and controls. Following mepolizumab initiation, MRS decreased at 6 and 12 months in GEMAS (p=4.81x10-5 and p=2.40x10-5, respectively). The 6-month decrease was also observed in MEGA (p=3.25x10-9). MRS epigenetic markers were predominantly hypermethylated, opposite to their described pattern in asthma risk. Conclusions. Asthma PRS did not differ significantly between biologic-treated and non-biologic-treated patients, but asthma MRS were lower in biologic-treated patients. The MRS decreased after mepolizumab initiation in two independent cohorts, consistent with a reversal of asthma-associated epigenetic patterns.

Background: Five biologics target sequential nodes of the type 2 (T2) inflammatory axis in severe asthma and have each been anecdotally linked to eosinophilic or paradoxical inflammatory adverse events. Whether these reflect a class effect or drug-specific signatures is untested. Methods: We performed a case-noncase disproportionality analysis of FAERS, 2022-2024. Asthma-indication reports naming tezepelumab, dupilumab, mepolizumab, benralizumab, or omalizumab as primary suspect were compared against the pooled other four (active-comparator design) across 7 pre-specified eosinophilic, vasculitic (including EGPA), cutaneous, and ocular outcomes. A signal was robust if the reporting odds ratio (ROR) 95% CI lower bound exceeded 1 and a Bayesian criterion was also met. Results: Among 50,360 reports (dupilumab n=29,652; mepolizumab n=8,846; omalizumab n=5,484; benralizumab n=4,372; tezepelumab n=2,006), benralizumab showed robust signals for EGPA (ROR 5.06), vasculitis (ROR 4.60), and peripheral eosinophilia (ROR 1.80). Mepolizumab showed a robust vasculitis signal (ROR 1.85); its similarly sized EGPA association narrowly missed the robustness criterion despite significance after correction for multiple testing. Dupilumab showed no EGPA/vasculitis excess but a robust ocular-inflammation signal (ROR 7.81). Tezepelumab and omalizumab showed no robust signal in any domain. EGPA/vasculitis onset occurred earlier after dupilumab (median 20-44 days) than anti-IL-5-axis agents (median 195-550 days; p[≤]0.012); mepolizumab's signal did not reproduce over the full 2015-2024 window (calendar-time confounding). Conclusion: FAERS active-comparator analysis reveals drug-specific, not class-uniform, adverse-event reporting patterns: anti-IL-5-axis agents disproportionately report EGPA/vasculitis, and dupilumab disproportionately reports ocular inflammation with markedly earlier onset. These hypothesis-generating signals cannot establish causality and require confirmation through case-level or comparative pharmacoepidemiological studies.

Rationale: The role of DNA methylation (DNAm) markers in the upper-airway microbiome related to asthma exacerbations despite inhaled corticosteroid (ICS) treatment is unexplored. Objectives: To identify whole-blood DNAm markers associated with the upper-airway microbiome related to asthma exacerbations despite ICS treatment. Methods: We analyzed salivary, nasal, and pharyngeal microbiome in 242 asthma patients (GEMAS) for discovery. We tested associations between whole-blood DNAm at 703,505 CpGs and 21 exacerbation-related microbiome traits. Replication for the nasal microbiome was evaluated in 272 (Project Viva) and 66 (SysPharmPediA) children with and without asthma. We analyzed differentially methylated regions (DMRs), gene enrichment, associations with blood gene expression (RNA-seq, n=119), and DNAm predictors of plasma proteins. Measurements and Main Results: Whole-blood DNAm at 73 CpGs and 550 DMRs was associated with 17 exacerbation-related microbiome traits (false discovery rate [FDR]<0.05), including genes implicated in immune and inflammatory responses and the 17q12-q21 asthma locus ORMDL3. Most CpGs were associated with Campylobacter (pharyngeal) and Leptotrichia (nasal) abundance. Ten DNAm markers were replicated (p<0.05), including the corticosteroid insensitivity-related gene PTPRR associated with nasal bacterial richness. Enrichment analyses identified genes related to diabetes, obesity, smoking, TGF-{beta}, and Wnt signaling and regulated by trichostatin A, NF-{kappa}B, and the glucocorticoid receptor (FDR<0.05). The CpG cg18994033, associated with pharyngeal Tannerella, was associated with ITM2C whole-blood expression. Nine DNAm-predicted plasma proteins involved in inflammation, tissue remodeling, and TGF-{beta} signaling were associated with seven exacerbation-related microbiome traits, including Streptococcus and Selenomonas. Conclusions: Whole-blood DNAm markers implicated in inflammation, immunity, and asthma comorbidities are associated with the upper-airway microbiome linked to asthma exacerbations.

The human host defence peptide LL-37 mediates pleiotropic immunomodulatory functions that can be both pro- and anti-inflammatory. Under inflammatory conditions in the lungs, LL-37 is susceptible to the post-translational modification (PTM) citrullination. The impact of this PTM on LL-37's immunomodulatory functions is not fully understood. Therefore, we characterized the transcriptome and cytokine profile in response to LL-37 and citrullinated-LL-37 (citLL-37), in human bronchial epithelial cells (HBEC). Cells were stimulated with either LL-37 or citLL-37 (0.5 M), or a scrambled peptide (sLL-37). RNA after 4 hours (h) was analyzed with NanoString nCounter Host Response Panel, and 96 cytokines were examined (after 24 h) in tissue culture supernatants (Luminex platform). Genes and cytokines with a Log2 fold-change [&ge;]0.5 with p<0.05 compared to unstimulated cells were considered differentially expressed (DE). These studies revealed overlapping and distinct biosignatures. There were 118 DE genes with LL-37 and 71 with citLL-37, of which magnitude of change was significantly different for 32 genes. 16 out of 17 DE genes altered by both peptides were directly related to inflammation, and these were significantly less (by ~45%) with citLL-37 compared to LL-37. Similarly, inflammatory cytokines enhanced in response to LL-37 were significantly less (by 37-94%) with citLL-37. Overall, our findings indicate that citrullination of LL-37 does not abrogate cellular response in HBEC, instead dampens the inflammatory biosignature induced by LL-37.

Background: Sex differences in asthma are well recognized, but sex-associated airway DNA methylation (DNAm) patterns and their relationships with gene expression remain incompletely characterized. We therefore conducted cis- and trans-expression quantitative trait methylation (eQTM) analyses using sex-stratified and CpG-by-sex interaction models. Methods: We analyzed nasal airway epithelial DNAm and transcriptomic data from 298 participants in the CAAPA discovery cohort. Asthma-associated differentially methylated CpGs (DMCs) were identified using sex-combined and sex-stratified models. Cis- and trans-eQTM analyses were then performed in participants with asthma using sex-combined, sex-stratified, and CpG-by-sex interaction models. To prioritize asthma-associated regulatory relationships, eQTMs that were also significant in non-asthmatic controls were excluded from downstream analyses. Replication in an independent bronchial epithelial cohort was defined by concordant effect direction and P < 0.05. Replicated targets underwent pathway and network analyses. Findings: Asthma-associated DMCs were predominantly hypomethylated in females and hypermethylated in males. Among trans-eQTMs, 379 associations were shared across all four models, whereas the majority were model-specific, indicating extensive sex-dependent regulatory architecture. We replicated 3, 1, 9, and 2 cis-eQTMs and 96, 84, 216, and 41 trans-eQTMs in the sex-combined, female-stratified, male-stratified, and interaction models, respectively. Sex-combined targets implicated innate immune and inflammatory signaling (TNF, IRF8); female-stratified targets implicated cytoskeletal remodeling, focal adhesion, and PI3K-Akt signaling (ITGA10); male-stratified targets implicated transcriptional regulation and post-translational modification (MOV10, HDAC7, CSF1, KAT2A); and interaction targets implicated lipid-mediator metabolism and inflammatory signaling and resolution (CYP2C9, LTB4R, CCL19). Our sex-dependent analyses showed that the majority of eQTMs resided within the trans-regulatory architecture, suggesting that sex-dependent gene expression differences are associated predominantly with trans rather than cis regulatory mechanisms. Pathway analyses revealed enrichment of innate immunity in the sex-combined model, structural remodeling in females, transcriptional control in males, and inflammatory resolution in the sex-interaction model. Interpretation: Sex-specific and sex-dependent airway methylation-expression associations were largely undetected by sex-combined analysis. Sex-aware analytical models may help resolve epigenetic mechanisms underlying sex differences in asthma biology.

Hypothyroidism has been associated with increased skin cancer risk, whereas greater genetic susceptibility to hypothyroidism is associated with lower risk. These opposing associations suggest that the average risk associated with hypothyroidism may conceal substantial heterogeneity among patients, and that genetic background could help identify those at highest risk. In this study, we analyzed more than 650,000 individuals across All of Us and FinnGen cohorts to determine whether a hypothyroidism polygenic risk score (H-PRS) stratifies skin cancer risk among patients with autoimmune hypothyroidism and whether integration of a skin cancer polygenic risk score (SC-PRS) further refines risk. In FinnGen, autoimmune hypothyroidism was associated with increased skin cancer hazard (hazard ratio [HR] = 1.10; 95% CI [1.06, 1.15]), whereas H-PRS was inversely associated with risk (HR=0.97 per 1-SD increase; 95% CI [0.95, 0.98]). The hypothyroidism x H-PRS interaction was also negative (HR=0.94; 95% CI [0.91, 0.98]), indicating greater hypothyroidism-associated risk at lower H-PRS. The hypothyroidism and H-PRS associations replicated in All of Us, and similar H-PRS risk gradients were observed for melanoma, basal cell carcinoma, and squamous cell carcinoma in both cohorts. Among hypothyroid patients, predicted 10-year risk increased with higher SC-PRS and lower H-PRS. Combined clinical-genetic profiles had HRs ranging from 2.32 at the 20th H-PRS/80th SC-PRS percentiles to 3.37 at the 5th/95th percentiles, exceeding published point estimates for the established dermatological risk factors. Among women aged 55, representing the more commonly affected sex at approximately the median age of diagnosis, 10-year risk of skin cancer was 14.9% (95% CI [8.4%, 20.9%]) in the highest-SC-PRS/lowest-H-PRS quartiles versus 2.8% (95% CI [1.0%, 4.7%]) in the opposite quartiles. Overall, these findings support PRS-guided risk stratification for targeted skin cancer prevention and surveillance.

Abstract Rationale: Vagal sensory neurons are molecularly and functionally diverse, and they play critical roles in visceral sensation and homeostasis. The vagal system is anatomically divided into jugular and nodose ganglia, which exhibit distinct peripheral innervation patterns and physiological functions. Although recent transcriptomic studies have characterized nodose neuronal subtypes in detail, the molecular profiles of jugular sensory neurons remain poorly defined. Objectives: To define the molecular profiles of genetically identified jugular sensory neurons and determine the transcriptional responses of jugular and nodose airway afferents to allergic airway inflammation. Methods: We performed deep transcriptomic profiling of two genetically defined jugular nociceptor populations, MrgprC11 and MrgprD neurons, and compared them with airway-innervating P2ry1 nodose neurons and Phox2b nodose neurons. We further examined transcriptional changes of MrgprC11 and P2ry1 neurons following OVA-induced allergic airway inflammation. Measurements and Main Results: Transcriptomic analyses revealed distinct molecular signatures of jugular nociceptive neurons and identified subtype-specific genes across diverse functional categories. Following OVA challenge, MrgprC11 and P2ry1 neurons exhibited strikingly divergent transcriptional responses. More than 400 genes that were differentially expressed in both neuronal populations were regulated in opposite directions. GO enrichment analysis suggested that MrgprC11 jugular neurons adopted a metabolically restrained state with reduced translation and bioenergetic activities, whereas P2ry1 nodose neurons exhibited metabolically active state with enhanced translation and bioenergetic activities. Conclusions: These findings provide new insight into vagal sensory neuron diversity and reveal distinct transcriptional adaptations of jugular and nodose airway afferents during allergic inflammation.

Psoriasis is a chronic skin disease characterized by red, scaly plaques mainly driven by dysregulated T cells that induce keratinocytes (KCs) proliferation and inflammation. Despite significant advancements in disease management through biologics and topical therapies, these treatments offer only temporary relief and fail to prevent disease recurrence. Considering the current therapeutic needs, we described herein a novel small molecule TEM1657, derived from 3,5-dicaffeoylquinic acid with anti-inflammatory potency in imiquimod-induced psoriasis mouse model as well as in Th17-stimulated KCs. Mechanistically, its action is mediated through modulation of mitochondrial dynamics, specifically via OPA1, an inner mitochondrial membrane protein that alters mitochondrial calcium influx, and further impacts cellular bioenergetics. Moreover, TEM1657 rapidly suppresses transcription of NFKBIZ and various other psoriasis-associated genes. These observations highlighted a pathway that represents an innovative target in psoriasis and other NFKBIZ-related disorders.

The bronchial epithelium in asthma is vulnerable to damage and has impaired barrier function, but the mechanisms by which it contributes to airway inflammation and remodelling remain unclear. Here, we dissect these epithelial and immunological disease mechanisms by establishing a comprehensive single cell atlas of the bronchial wall from 21 patients with childhood-onset asthma and 25 matched healthy controls. We identify a novel asthma-associated non-canonical epithelial differentiation trajectory in which a repair-associated KLF4+ basal cell subset differentiates into KRT13+ hillock-like cells through a proliferative KRT14+ intermediate. In vitro cultured matched primary bronchial epithelial cells show that this trajectory is retained in absence of exogenous factors. We find that IL-13 induces hillock-like cell differentiation into CEACAM5hi goblet cells, driving goblet cell metaplasia. Repair-associated basal cells and transitioning CEACAM5hi hillock-like cells strongly contribute to airway inflammation and remodelling. In turn, dendritic cells and mast cells promote a state of highly active epithelial differentiation, which shows increased multiciliated cell fate decisions, in concordance with an increase in multiciliated cell death observed in asthma. Proportions of the epithelial cells of the non-canonical differentiation trajectory are associated with clinical outcomes such as disease severity, FeNO, and small airway function.

Background Vitiligo is an acquired depigmenting disorder characterised by melanocyte loss. While immune responses against melanocytes are implicated in its pathogenesis, melanocyte detachment, melanocyte senescence and aberrant epidermal differentiation are increasingly characterised as additional pathological features. Granzyme B (GzmB), classically recognised as an intracellular effector of perforin-dependent cytotoxicity, is increased in vitiligo lesions; however, its extracellular contribution to vitiligo pathology remains unclear. Objectives To determine whether extracellular GzmB contributes to depigmentation and epidermal pathological features relevant to vitiligo, and to define its cellular source and underlying mechanisms. Methods Human vitiligo skin samples, murine depigmentation models and cultured human epidermal cells were analysed. The functional effects of extracellular GzmB were examined by subcutaneous administration of recombinant GzmB in mice. A rhododendrol (RD)-induced leukoderma model was used to evaluate the disease relevance of GzmB and the therapeutic effect of topical GzmB inhibition with VTI-1002. Results GzmB-positive cells were markedly increased in active vitiligo lesions and were predominantly associated with tryptase-positive cells, with limited co-distribution with CD8 or perforin. Vitiligo lesions also showed melanocyte detachment, increased p16INK4A-positive melanocytes and aberrant keratinocyte differentiation. These pathological features were recapitulated in vivo by extracellular GzmB administration, accompanied by focal depigmentation. In cultured melanocytes, GzmB exerted no cytotoxic effects but reduced attachment strength and induced a senescence-associated phenotype characterised by decreased extracellular matrix- and adhesion-related gene expression, increased p16INK4A level, elevated senescence-associated {beta}-galactosidase activity and activation of transforming growth factor-{beta}/SMAD signalling. In keratinocytes, extracellular GzmB promoted aberrant differentiation associated with activation of p53 signalling. Topical inhibition of GzmB in RD-induced leukoderma attenuated depigmentation progression, melanocyte detachment, melanocyte senescence and abnormal epidermal differentiation. Conclusions Extracellular GzmB promotes depigmentation associated with inducing melanocyte detachment, melanocyte senescence and aberrant keratinocyte differentiation. These findings identify extracellular GzmB as a previously underrecognised pathogenic mediator and potential therapeutic target in vitiligo-associated depigmentation.

Background: Millions of textile and agricultural workers inhale organic dust containing endotoxin, an exposure associated with impaired respiratory function. However, the underlying biological pathways remain unclear. We conducted a two-cohort epigenome-wide association study (EWAS) to identify airborne endotoxin-associated DNA methylation (DNAm) alterations and pathways. Methods: In the discovery phase, we compared blood DNAm in 281 endotoxin-exposed cotton workers and 253 unexposed silk-workers from the Shanghai Textile Worker Study (STWS) measured using Illumina MethylationEPICv2 arrays. STWS endotoxin assessment combined detailed work histories and onsite measurements. For targeted parallel validation, we tested STWS signals in 686 incident lung cancer cases and 683 matched controls from the Shanghai Women's Health Study (SWHS), using occupation-derived low, medium, or high exposure-intensity ranks based on published evidence. To gain biological insight, we analyzed pathway enrichment, immune-cell composition, DNAm inflammation risk scores (IRSs), and respiratory phenotype associations in STWS. Results: In STWS, we identified 36 epigenome-wide significant DNAm sites (P<5e-8), of which, 35 were hypomethylated. Among 30 sites testable in SWHS, 18 had concordant effect directions, and four were nominally significant: cg11869499 (POLG; P=0.041), cg16290931 (TSKS; P=0.044), cg05019530 (EPIC1; P=0.042), and cg26033526 (PSMB9/TAP1; P=0.013). Enrichment implicated immune and signal-transduction pathways, including IgSF cell-adhesion-molecule signaling (FDR=8.2e-6;). Neutrophil were higher in cotton workers than in silk workers (63.5% vs 58.9%, p=7.52e-10). Cumulative endotoxin was associated with higher CRP-based IRSs, which showed the most consistent associations with lower lung function and airflow obstruction. Conclusions: Our EWAS findings suggest that occupational endotoxin may operate partly through immune-cell composition and inflammatory pathways.

Background. The cholinergic anti-inflammatory pathway regulates inflammation through vagus signaling that activates the 7 nicotinic acetylcholine receptor (7nAChR) on leukocytes. Suppression of macrophage inflammatory cytokine production through 7nAChR-mediated inhibition of NF-{kappa}B activation is considered a central mechanism of this pathway. However, the effects of cholinergic activation of 7nAChR on neutrophils remain poorly understood. Here, we investigated whether and how activation of 7nAChR in neutrophils regulates neutrophil migration, defined the underlying molecular mechanism, and evaluated its contribution to anti-inflammatory protection during endotoxemia. Results. The ex vivo swarming assays revealed that activation of 7nAChR with the selective agonists PNU-282987 and AR-R17779 significantly inhibited human and mouse neutrophil migration. The inhibitory effect of PNU-282987 was abolished in 7nAChR-deficient neutrophils, confirming receptor specificity. Mechanistically, 7nAChR activation reduced integrin M{beta}2 activation, decreased F-actin polymerization, and impaired neutrophil polarization. These effects required M{beta}2, as PNU-282987 failed to inhibit actin remodeling in M-deficient neutrophils. Modulation of M{beta}2 activation with an activating antibody (MEM48) demonstrated that 7nAChR regulates neutrophil migration by limiting excessive M{beta}2 activation and maintaining an optimal adhesive state. In vivo, adoptively transferred fluorescently labeled PNU-282987-treated neutrophils exhibited reduced recruitment to the lungs compared with vehicle-treated neutrophils during LPS-induced endotoxemia. Furthermore, neutrophil depletion markedly diminished the protective effect of PNU-282987 on survival, demonstrating that neutrophils contribute to 7nAChR-mediated protection during systemic inflammation. Conclusions. Our findings identify neutrophils as an important cellular target of the cholinergic anti-inflammatory pathway and demonstrate that 7nAChR activation limits neutrophil migration by suppressing integrin M{beta}2 activation and actin cytoskeletal remodeling. Together, these findings establish M{beta}2 as a critical downstream effector of 7nAChR signaling in neutrophils and identify regulation of integrin activation as a previously unrecognized mechanism of the cholinergic anti-inflammatory pathway.

Background: Common variable immunodeficiency is frequently underrecognized due to its heterogeneous clinical presentation, resulting in diagnostic delays that increase disease-related complications, with each year of delay increasing mortality risk by 4% for the most common inborn error of immunity. Objective: In individuals with established common variable immunodeficiency, we sought to recognize patterns in patient diagnostic trajectories to identify opportunities for interventions to reduce time to diagnosis. Methods: We analyzed retrospective electronic health records data from 139 individuals with physician-confirmed common variable immunodeficiency across five academic health systems representing >10million patients. We evaluated diagnosing specialties and international classification of disease code trajectories in the two years prior to and at common variable immunodeficiency confirmation. Additionally, we construct specialty-specific prediction on a 1:50 case: control cohort using a gradient boosting algorithm. Results: The leading diagnoses at common variable immunodeficiency determination were respiratory (35% of individuals), and individuals with respiratory symptoms were more likely to be diagnosed by Allergy / Immunology than by other specialties (odds ratio 2.9, standard error 0.35, p-value 1.9x10-3) and had a higher frequency of visits to pulmonary disease in the two years prior to diagnosis. Individuals with neoplasms were 50% more likely than other patients (OR 2.0, SE 0.29, p-value 0.02) to receive a diagnosis at each visit, reducing their diagnostic delay by up to a year. We find that a larger ratio of number of specialties visited to the total number of visits is significantly correlated with an increased time to diagnosis. A trajectory-informed specialty-specific prediction improved detection with an area under the precision-recall curve of fifty times the value expected under the null. Conclusions: Individuals referred to Allergy / Immunology have shorter time to diagnosis, and a specialty-specific prediction could improve detection of common variable immunodeficiency. Clinical Implications: Overall, we find that phenotype-specialty interactions may inform targeted interventions to improve common variable immunodeficiency recognition across specialties, reducing diagnostic odyssey and disease-related complications.

BackgroundEarly-life air pollution exposure has been associated with childhood asthma, but its relative contribution is poorly characterised in cohorts with repeated indoor measurements. Short sampling windows and seasonal bias limit how well any single measurement can represent cumulative exposure. ObjectiveTo evaluate the association between early-life indoor and outdoor pollutant exposure from birth to 18 months and asthma development at ages 7, 12, and 18 years, while testing potential exposure-exposure and gene-environment interactions. MethodsIn the COPSAC2000 birth cohort (n = 411), indoor PM2.5, black carbon, NO2, NOx and VOCs, and modelled outdoor PM2.5, NO2 and NOx, were assessed at 6, 12 and 18 months of age. Indoor metrics were corrected for pump-flow drift and seasonal bias via a Gaussian process with a periodic kernel. Hierarchical Bayesian logistic regression(HBLR) and calibrated random forests (CRF) were evaluated using stratified nested cross-validation for discrimination using AUC-ROC, Calibration using integrated calibration index (ICI), and Brier skill scores. Exposure-exposure and gene-environment interactions were quantified via Shapley interaction indices. ResultsDiscrimination was weak at all endpoints with test AUC-ROC: 0.58-0.67, BSS near zero (0.012 to 0.05) and ICI: 0.043-0.061 for random forest and AUC-ROC 0.53-0.61, BSS equal to zero and ICI: 0.054-0.067 for hierarchical Bayesian logistic regression (HBLR). No pollutant reached a highest density interval excluding OR = 1. The polygenic risk score(PRS) was the only term non-null at all three ages in the adjusted models. While gene-environment interactions were detected, effect sizes were negligible and statistically indistinguishable from zero. SignificanceWhere ambient pollution is low, cumulative early-life exposure adds little to long-term asthma prediction beyond genetic and contextual factors, and an improved exposure correction does not uncover an effect. ImpactRepeated bedroom measurements across infancy are rare, and short sampling windows make them hard to read as cumulative exposure. We corrected measured concentrations for pump-flow drift and for seasonal sampling bias on the pollutants and used two complementary machine learning models to predict interaction and risk. In this low-exposure Danish cohort, genetic risk and residential context dominated, and the measured pollutants added almost nothing to the asthma risk at 7,12 and 18 years. These null results indicate that early cumulative exposures of indoor and outdoor air pollution contribute little to nothing to asthma up to 18 years.

Systemic sclerosis (SSc) is an autoimmune connective tissue disease characterized by symmetric fibrosis of the skin and multiple internal organs. The mechanisms that trigger early fibrotic changes remain unclear. Mast cells are known to infiltrate human SSc lesional skin in early disease stages, yet the role of mast cells in initiating fibrosis and pruritus in SSc remains debated, in part due to unclear pathways of mast cell activation. Here, we show that mast cells, via the receptor Mrgprb2, contribute to fibrosis in the bleomycin (BLM)-induced skin fibrosis mouse model. Mast cells accumulate in the skin of BLM-treated wild-type (WT) but not Mrgprb2-knockout (Mrgprb2-/-) mice. Mrgprb2-/- mice show attenuated disease severity, with reduced collagen deposition and lower expression of matrix metalloproteinases and inflammatory markers associated with fibrosis. BLM treatment also increases pruritus in WT mice in the early stages of the model; an effect reduced in Mrgprb2-/- mice. This is the first report of itch in this model of skin fibrosis, further linking it to clinical SSc, where pruritus is an early and prevalent symptom affecting nearly half of patients. In a parallel human cohort, lesional SSc skin harbors significantly more mast cells than paired non-lesional skin from the same patients, demonstrating that mast cell accumulation is specific to affected tissue. Lesional mast cell counts also track with skin disease severity, correlating with modified Rodnan skin score and patient-reported skin tightness. Together, these findings implicate Mrgprb2-mediated mast cell activity in both fibrosis and pruritus in SSc, highlighting mast cells as a candidate therapeutic target in this understudied disease process.

How inflammation is established and resolved within tissues remains a fundamental question in human biology. Psoriasis is a chronic inflammatory skin disease driven by the IL-23/IL-17 pathway, with IL-17 pathway targeting biologics producing more rapid clinical improvement than IL-23 inhibitors. This difference raises the question of how IL-17 and IL-23 inhibition differentially remodel the cellular and transcriptional landscape of psoriatic skin during resolution. Here, we generated a longitudinal spatial atlas of plaque psoriasis using 2 micron high-definition spatial transcriptomics (HD-SPT), profiling 42 matched biopsies from 11 biologic treatment-naive patients before and during IL-17- or IL-23-targeted therapy. By integrating HD-SPT with a single-cell RNA-sequencing (sc-RNAseq) reference atlas, we resolved the cellular composition and spatial organization of psoriatic skin and mapped its remodeling during treatment. We identified a distinct cluster of SPRR2F+ keratinocytes (KCs) that was spatially restricted to the upper stratum granulosum at the transition to the stratum corneum and was strongly associated with inflamed psoriatic epidermis. SPRR2F+ KCs were enriched for antimicrobial and inflammatory barrier genes, including S100A8, S100A9, LCN2, IL36G, and PI3, and their abundance correlated with disease activity during treatment. In psoriasis patient-derived human epidermal KCs (P-HEK), SPRR2F knockdown attenuated inflammatory and antimicrobial transcriptional responses, supporting a functional role for SPRR2F in sustaining the inflammatory KC response in psoriasis. Longitudinal profiling further revealed distinct trajectories of tissue remodeling following IL-17 and IL-23 inhibition. Following IL-17 inhibition, SPRR2F+ KCs and their characteristic transcriptional signature resolved rapidly, whereas IL-23 inhibitors produced more gradual resolution of KC-centered transcriptional changes accompanied by broader immune and stromal remodeling. Together, these findings established the first HD-SPT atlas of a human skin disease and revealed distinct cellular and transcriptional trajectories of psoriatic skin during therapeutic resolution, identifying SPRR2F as a regulator of persistent KC inflammation.

Background: Obesity is associated with airway disease, but the contribution of specific thoracic adipose depots remains unclear. We examined whether intrathoracic adipose tissue (ITAT), defined as adipose tissue within the thoracic cavity excluding pericardial adipose tissue (PAT), was associated with airway phenotypes. Methods: We included Framingham Heart Study participants with CT-derived thoracic adipose tissue measures. Cross-sectional associations of ITAT with CT-based airway wall and lumen measurements, spirometry, and respiratory symptoms were evaluated using multivariable regression. Primary analyses used sex-specific ITAT z-scores and adjusted for waist circumference to account for central obesity. Secondary analyses examined sex-specific ITAT quintiles and compared ITAT and PAT in individual-depot and mutually adjusted models. Results: Among 2,825 adult participants (52.0% female), after adjustment for waist circumference, each 1-SD higher ITAT, relative to the sex-specific distribution, was associated with greater segmental ({beta} [95% CI]: 0.010 mm [0.006, 0.014]) and subsegmental airway wall thickness (0.006 mm [0.002, 0.009]), narrower segmental airway lumen diameter (-0.049 [-0.088, -0.011]), lower FEV1 percent predicted (-1.92 percentage points [-2.72, -1.12]), and higher odds of wheezing (OR [95% CI]: 1.16 [1.02, 1.31]) and dyspnea (1.22 [1.05, 1.42]). Associations were similar after further adjustment for PAT and across ITAT quintiles. In contrast, PAT was not independently associated with airway structural measures after adjustment for ITAT. Conclusion: Higher ITAT volume was associated with greater airway wall thickness and narrower airway lumen, as well as lower FEV1 and greater respiratory symptoms, independent of central obesity and pericardial adiposity. These findings support a depot-specific association of ITAT with airway disease.