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Biology subjects

Hallstrand, T. S.

Publications and source records attributed to Hallstrand, T. S..

5 recordsLinked to original sources

IL-13 Modulates Antiviral Effector and Proinflammatory Pathways in Rhinovirus-Infected Pediatric Bronchial Epithelium

BackgroundRhinovirus (RV) is the most common trigger of viral-induced pediatric asthma exacerbations. The impact of IL-13-driven inflammation, common in pediatric asthma, on airway epithelial antiviral and inflammatory responses to RV remain unclear. ObjectiveDetermine how IL-13-driven T2 inflammation modulates pediatric bronchial epithelial cell responses to RV infection. MethodsBronchial epithelial cells (BECs) were collected from children with (n=50) and without (n=11) asthma. They were differentiated at an air-liquid interface for 21 days, pretreated with IL13 (10ng/mL) for 7 days to model T2 inflammation, then infected with RV-A16 (MOI 0.5). RNA sequencing of BECs was performed prior to and on days 2, 4, 7, and 10 post infection. Linear and generalized additive models partnered with pathway analysis identified differentially expressed gene clusters. ResultsRV infection, IL-13 stimulation, and their interaction each induced differentially expressed genes (7,808; 10,251; and 7,095 genes, respectively; FDR<0.05). IL-13 pretreatment did not alter RV load or a cluster enriched for interferon response and regulation genes, including IFNB1, IFNL1-3, STAT1/2, and CXCL10/11. In contrast, IL-13 reduced expression of distinct antiviral effectors (e.g. MX1/2, RSAD2, IFITM1-3; FDR=1.85x10-) and increased a secondary proinflammatory response cluster enriched for IL-15, TNF, ER stress, and cell-death pathways (FDR=3.63x10-). These clusters correlated with viral load in RV-infected cells, but IL13 pretreatment eliminated those associations. ConclusionsIL-13 does not modify viral load or interferon induction but selectively suppresses epithelial antiviral effector programs and enhances secondary inflammatory pathways during RV infection. These findings provide mechanistic insight into how T2 inflammation contributes to viral-triggered asthma morbidity. Key Messages- IL-13 did not alter rhinovirus viral load or epithelial interferon induction but selectively suppressed antiviral effector programs. This indicates that T2 inflammation reshapes antiviral defenses downstream of interferon signaling rather than impairing interferon production itself. - IL-13 enhances a distinct secondary proinflammatory cluster enriched for IL-15, TNF signaling, ER stress, and cell-death pathways. These late-phase responses may contribute to the heightened airway inflammation and injury observed during viraltriggered exacerbations in T2-high pediatric asthma. - IL-13-driven changes decouple epithelial immune responses from viral load, revealing mechanisms that may persist even with anti-IL-4R/IL-13 therapy. These findings identify epithelial antiviral effector pathways and IL-15/TNF-associated inflammatory programs as potential therapeutic targets for patients who experience breakthrough viral exacerbations despite IL-13 blockade. Capsule SummaryIL-13 did not alter rhinovirus load or epithelial interferon but selectively suppressed antiviral effectors and amplified secondary inflammatory pathways, revealing how T2-inflammation may worsen viral-triggered asthma exacerbations and contribute to breakthrough exacerbations despite IL-4R/IL-13-targeted therapy.

cell biology↗

Transcriptomic Profiling of Bronchial Epithelium Reveals Dysregulated Interferon and Inflammatory Responses to Rhinovirus in Exacerbation-Prone Pediatric Asthma

Host factors influencing susceptibility to rhinovirus-induced asthma exacerbations remain poorly characterized. Using organotypic bronchial epithelial cultures from well-characterized children with asthma and healthy children, this study investigated viral load kinetics and resultant host responses by bulk and single-cell transcriptomics and targeted protein analyses. Bronchial epithelium from exacerbation-prone children exhibited greater rhinovirus replication and a cascade of exaggerated downstream interferon (IFN), inflammatory, epithelial stress, and remodeling responses. These transcriptional patterns were confirmed and further refined using single-cell transcriptomics, revealing cell type-specific contributions--particularly from non-ciliated cell populations including secretory immune response, tuft, and basal cells. We observed that these post-infection differences were associated with lower pre-infection IFN-stimulated gene (ISG) expression and protein levels of the ISG CXCL10. Prophylactic IFN-{beta} treatment reduced viral replication and normalized downstream responses, supporting low baseline (pre-infection) IFN tone as a modifiable causal determinant of host susceptibility to adverse rhinovirus-induced responses in exacerbation-prone children with asthma.

cell biology↗

Viral replication and interferon responses in bronchial epithelia is enhanced by Th17 cells

RationaleThe impact of Th17 lymphocytes on epithelial responses to rhinovirus infection in asthma is poorly characterized. MethodsBronchial epithelial cells (BECs) from children with asthma were differentiated to an organotypic epithelium and primed via co-culture with healthy donor Th17 lymphocytes for 4 days prior to apical infection with human rhinovirus-16 (RV-16). RNA sequencing with WGCNA analysis was performed to identify modules of gene expression altered by Th17 priming or RV-16 infection in BECs or Th17 cells. Gene expression was correlated with viral copy number and with secreted protein levels. ResultsAnalysis identified 4,030 genes grouped into 9 named modules with differential gene expression in BECs due to Th17 priming and viral infection. Modules with increased expression with Th17 priming and RV-16 infection included Interferon, MAP-kinase and TNF Signaling modules, while expression of Cilia structure/function and Metabolism modules were decreased. Th17 cells co-cultured with RV-16 infected BECs exhibited increased expression of an Interferon and Viral Response Module without detectable direct viral infection of Th17 cells.Increased expression of the Interferon Signaling in BECs and Interferon Response in Th17 cells was correlated with increased viral copy number in BECs. Th17 priming of BECs led to increased secretion of IFN-, IFN-{gamma}, and IL-1{beta} following RV-16 as compared to BECs alone. ConclusionsTh17 lymphocytes enhance epithelial interferon responses to RV-16 infection in bronchial epithelium from asthmatic children.

cell biology↗

Increased epithelial mTORC1 activity in chronic rhinosinusitis with nasal polyps

BackgroundThe airway epithelium plays a central role in the pathogenesis of chronic respiratory diseases such as asthma and chronic rhinosinusitis with nasal polyps (CRSwNP), but the mechanisms by which airway epithelial cells (EpCs) maintain inflammation are poorly understood. ObjectiveWe hypothesized that transcriptomic assessment of sorted airway EpCs across the spectrum of differentiation would allow us to define mechanisms by which EpCs perpetuate airway inflammation. MethodsEthmoid sinus EpCs from adult patients with CRS were sorted into 3 subsets, bulk RNA sequenced, and analyzed for differentially expressed genes and pathways. Single cell RNA-seq (scRNA-seq) datasets from eosinophilic and non-eosinophilic CRSwNP and bulk RNA-seq of EpCs from mild/moderate and severe asthma were assessed. Immunofluorescent staining and ex vivo functional analysis of sinus EpCs were used to validate our findings. ResultsAnalysis within and across purified EpC subsets revealed an enrichment in glycolytic programming in CRSwNP vs CRSsNP. Correlation analysis identified mammalian target of rapamycin complex 1 (mTORC1) as a potential regulator of the glycolytic program and identified EpC expression of cytokines and wound healing genes as potential sequelae. mTORC1 activity was upregulated in CRSwNP, and ex vivo inhibition demonstrated that mTOR is critical for EpC generation of CXCL8, IL-33, and CXCL2. Across patient samples, the degree of glycolytic activity was associated with T2 inflammation in CRSwNP, and with both T2 and non-T2 inflammation in severe asthma. ConclusionsTogether, these findings highlight a metabolic axis required to support epithelial generation of cytokines critical to both chronic T2 and non-T2 inflammation in CRSwNP and asthma. KEY MESSAGESO_LIEpithelial mTORC1 activity is upregulated in CRSwNP. C_LIO_LImTOR regulates EpC cytokine generation. C_LIO_LIEpithelial metabolic reprograming correlates with T2 inflammation in CRSwNP, and with both T2 and non-T2 inflammation in asthma. C_LI CAPSULE SUMMARYmTORC1 mediates EpC cytokine generation in CRSwNP.

immunology↗

Airway epithelial interferon response to SARS-CoV-2 is inferior to rhinovirus and heterologous rhinovirus infection suppresses SARS-CoV-2 replication

IntroductionCommon alphacoronaviruses and human rhinoviruses (HRV) induce type I and III interferon (IFN) responses important to limiting viral replication in the airway epithelium. In contrast, highly pathogenic betacoronaviruses including SARS-CoV-2 may evade or antagonize RNA-induced IFN I/III responses. MethodsIn airway epithelial cells (AECs) from children and older adults we compared IFN I/III responses to SARS-CoV-2 and HRV-16, and assessed whether pre-infection with HRV-16, or pretreatment with recombinant IFN-{beta} or IFN-{lambda}, modified SARS-CoV-2 replication. Bronchial AECs from children (ages 6-18 yrs.) and older adults (ages 60-75 yrs.) were differentiated ex vivo to generate organotypic cultures. In a biosafety level 3 (BSL-3) facility, cultures were infected with SARS-CoV-2 or HRV-16, and RNA and protein was harvested from cell lysates 96 hrs. following infection and supernatant was collected 48 and 96 hrs. following infection. In additional experiments cultures were pre-infected with HRV-16, or pre-treated with recombinant IFN-{beta}1 or IFN-{lambda}2 before SARS-CoV-2 infection. ResultsDespite significant between-donor heterogeneity SARS-CoV-2 replicated 100 times more efficiently than HRV-16. IFNB1, INFL2, and CXCL10 gene expression and protein production following HRV-16 infection was significantly greater than following SARS-CoV-2. IFN gene expression and protein production were inversely correlated with SARS-CoV-2 replication. Treatment of cultures with recombinant IFN{beta}1 or IFN{lambda}2, or pre-infection of cultures with HRV-16, markedly reduced SARS-CoV-2 replication. DiscussionIn addition to marked between-donor heterogeneity in IFN responses and viral replication, SARS-CoV-2 elicits a less robust IFN response in primary AEC cultures than does rhinovirus, and heterologous rhinovirus infection, or treatment with recombinant IFN-{beta}1 or IFN-{lambda}2, markedly reduces SARS-CoV-2 replication.

immunology↗