Journal of Allergy and Clinical Immunology最新文献

Background: Partial recombinase activating gene deficiency (pRD) leads to combined immunodeficiency with immune dysregulation. It can be cured by allogeneic hematopoietic cell transplantation (HCT), but optimal referral criteria and approaches remain to be defined.

Objective: Our study evaluated low-toxicity approaches to HCT for pRD.

Methods: Thirteen children and adults with pRD received radiation-free, predominantly reduced-intensity conditioning (pentostatin/cyclophosphamide/busulfan) HCT with posttransplantation cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis at median (range) age 20 (4-46) years.

Results: With median 2.6 years' follow-up, overall survival for the entire cohort was estimated at 92% and 83% at 1 and 2 years and 100% and 90% for reduced-intensity conditioning recipients (n = 12), with 2 deaths attributed to sepsis. Reversal of clinical manifestations was associated with immune reconstitution, with minimal de novo autoimmunity, 15% 1-year cumulative incidence of grade III-IV acute GVHD, and no chronic GVHD. Vα7.2-positive T-cell proportion increased rapidly after HCT, while mucosa-associated invariant T-cell reconstitution lagged. Dysreactive CD19^hiCD21^lo and 9G4⁺ B cells decreased after HCT, along with clinically relevant autoantibodies. However, baseline elevated anti-type I interferon antibodies, potentially predisposing to severe viral infections, decreased slowly, although neutralizing activity was reduced at last follow-up. Outcomes did not differ by donor carrier status or HLA matching. Bronchiectasis exacerbations incurred rehospitalizations in long-term follow-up of patients who entered HCT with irreversible lung disease.

Conclusion: Reduced-intensity conditioning HCT with posttransplantation cyclophosphamide-based GVHD prophylaxis is safe and effectively reverses immune dysfunction in patients with pRD.

Background: Eosinophilic esophagitis (EoE) is a progressive fibrostenotic disease. Although proton pump inhibitors (PPIs) are a first-line EoE treatment due to their anti-inflammatory effects, their effects on remodeling/fibrosis-likely driven in part by transforming growth factor β (TGF-β)-remain uncertain.

Objective: To elucidate remodeling/fibrosis effects, this study evaluated whether PPIs impact the esophageal transcriptome of PPI-responsive EoE and counteract TGF-β‒induced fibrotic responses in human primary esophageal fibroblasts (HEFs).

Methods: Prospectively collected paired esophageal biopsies from patients with EoE pre‒/post‒PPI treatment were analyzed by RNA sequencing (RNA-seq). Histologic responsiveness to PPIs was defined as responders (<15 eosinophils/high-power field, n = 10) or non-responders (≥15 eosinophils/high-power field, n = 9). The ability of PPIs (esomeprazole, omeprazole) to attenuate in vitro, TGF-β‒mediated remodeling/fibrosis in HEFs was analyzed by qPCR, RNA-seq, Western blotting, immunofluorescence, cell migration assays, and reactive oxygen species (ROS) measurements.

Results: In PPI responders, we identified 746 differentially expressed genes pre‒/post‒PPI treatment (≥2-fold change, P < .05), particularly those enriched in remodeling/fibrosis. In HEFs, TGF-β increased collagen I and α-smooth muscle actin expression via SMAD2/3 phosphorylation; however, PPIs attenuated these responses. RNA-seq revealed that PPIs reversed approximately 30% of TGF-β‒induced changes overlapping with fibrotic responses; 78 genes were concordantly modulated between patient biopsies and HEFs. Functional assays further confirmed that PPIs reduced TGF-β-induced collagen deposition, fibroblast motility, and ROS production.

Conclusions: PPIs modulate remodeling/fibrosis-related gene expression in patients with EoE and inhibit TGF-β‒induced profibrotic responses in HEFs, supporting antifibrotic potential that may help limit fibrostenotic progression in EoE.

Background: Concomitant exposure to interleukin (IL)-33, thymic stromal lymphopoietin (TSLP), and IL-25 augments antigen-induced contractions of isolated human small bronchi through enhanced mast cell reactivity.

Objective: The individual contribution of alarmins was tested in antigen-induced airway hyperresponsiveness and hyperosmolarity-induced responses evoked by mannitol, a surrogate model of exercise-induced bronchoconstriction.

Methods: Intact segments of small airways, isolated from fresh human lung tissue, were incubated with IL-33, TSLP, IL-25, or buffer control for 48 hours. Contractile responses to anti-IgE or mannitol were then assessed using myograph systems. Mast cell degranulation and mediator release were analysed both from the bronchial segments and from isolated primary human lung mast cells (HLMCs) as well as from the human mast cell line LAD2.

Results: IL-33 increased contractile force (E_max) to anti-IgE and hyperosmolar mannitol by 62% and 78%, respectively. IL-33 also doubled antigen-IgE-induced prostaglandin (PG)D₂ release from bronchial segments as well as enhanced degranulation, cysteinyl-leukotriene (cysLT) and PGD₂ release from isolated HLMCs stimulated by anti-IgE or mannitol. In contrast, TSLP and IL-25 had no effect on contraction, degranulation, or mediator release in response to either stimulus.

Conclusion: IL-33, but not TSLP or IL-25, enhances bronchoconstriction in human small bronchi by amplifying mast cell activation and mediator release in response to both antigen and hyperosmolar challenge.

Background: Epithelial remodeling is a key pathologic feature of eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP). Among the various remodeling patterns, squamous metaplasia remains an underrecognized component in eCRSwNP.

Objective: This study aimed to systematically assess the prevalence of squamous metaplasia in eCRSwNP and explore its potential mechanisms.

Methods: A total of 844 chronic rhinosinusitis with nasal polyps specimens were histologically reviewed to assess the prevalence of squamous metaplasia and compare rates between eCRSwNP and noneosinophilic (neCRSwNP) subtypes. RNA sequencing was used to profile related gene expression in controls, neCRSwNP, and eCRSwNP tissues, with reverse transcription quantitative PCR and immunofluorescence validation in an independent cohort. Nasal epithelial cells were cultured in an air-liquid interface (ALI) system, stimulated with IL-4/IL-13 and dupilumab to evaluate morphologic and molecular changes.

Results: Of the 844 chronic rhinosinusitis with nasal polyps samples, 132 (15.6%) showed squamous metaplasia, with higher prevalence in eCRSwNP (25.7%) compared to neCRSwNP (7.5%). Transcriptomic analysis revealed significantly elevated expression scores of keratinocyte differentiation-related genes in eCRSwNP, with KRT6A and KRT13 markedly upregulated. Cohort validation confirmed increased mRNA and protein levels of KRT6A, KRT13, filaggrin, p63, and Ki-67 in eCRSwNP, predominantly localized to the epithelium. In vitro, IL-4/IL-13 exposure induced squamous alterations in ALI cultures, characterized by increased expression of squamous differentiation markers and reduction in ciliated and secretory cell markers. These pathologic changes were attenuated by dupilumab treatment.

Conclusion: Squamous metaplasia is a common but underappreciated epithelial remodeling feature in eCRSwNP. IL-4/IL-13 drive this pathologic shift, whereas dupilumab attenuates these changes, suggesting a role in preserving epithelial homeostasis beyond inflammation control.

Background: Since the coronavirus disease 2019 pandemic, local immune responses in the nasal mucosa have become an area of growing research interest. In this context, studies using noninvasive nasal brushing (NB) samples have increased markedly. However, it remains unclear whether NB samples accurately reflect the immune landscape of the nasal tissue (NT).

Objective: A study was conducted to directly compare the cellular composition and immune cell responses of NB and NT samples.

Methods: Paired NB and NT samples were collected from the same anatomic site. The frequency, phenotype, and effector functions of epithelial and immune cells were analyzed by single-cell RNA sequencing and flow cytometry.

Results: NB samples contained a significantly higher proportion of epithelial cells than NT samples, while fibroblasts, endothelial cells, and B cells were significantly less abundant. Within the epithelial compartment, NB showed an enrichment of ciliated and secretory cells, whereas basal cells were less frequent and glandular basal/secretory cells were rarely detected. Additionally, CD103⁺ tissue-resident memory T cells and CD56^bright natural killer cells were more abundant in NB samples than in NT samples. Functional analyses revealed distinct T-cell effector profiles between the two sample types. Notably, severe acute respiratory syndrome coronavirus 2-specific T cells were significantly less frequent in NB samples than in NT.

Conclusions: NB is well suited for sampling cells located near the epithelial surface but captures fewer cells from deeper mucosal layers. Additionally, NB samples display distinct T-cell effector profiles and virus-specific T-cell frequencies compared with NT. These findings highlight the importance of selecting sampling methods that align with the specific objectives of a study.