Allergens abrogate antiinflammatory DNA effects and unmask macrophage-driven neutrophilic asthma via ILC2/STING/TNF-α signaling
Anand Sripada, Divya Verma, Rangati Varma, Kapil Sirohi, Carolyn Kwiat, Mohini Pathria, Mukesh Verma, Anita Sahu, Vamsi Guntur, Laurie Manka, Brian Vestal, Camille Moore, Richard J. Martin, Magdalena M. Gorska, John Cambier, Andrew Getahun, Rafeul Alam
Anand Sripada, Divya Verma, Rangati Varma, Kapil Sirohi, Carolyn Kwiat, Mohini Pathria, Mukesh Verma, Anita Sahu, Vamsi Guntur, Laurie Manka, Brian Vestal, Camille Moore, Richard J. Martin, Magdalena M. Gorska, John Cambier, Andrew Getahun, Rafeul Alam
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Research Article Immunology Inflammation Pulmonology

Allergens abrogate antiinflammatory DNA effects and unmask macrophage-driven neutrophilic asthma via ILC2/STING/TNF-α signaling

Abstract

The mechanisms of neutrophilic and mixed neutrophilic-eosinophilic asthma are poorly understood. We found that extracellular DNA and nucleosomes (Nucs) were elevated in the airways of patients with neutrophilic-eosinophilic asthma and correlated with bronchoalveolar lavage neutrophils. Bronchial tissue from neutrophilic-eosinophilic asthma had more DNA sensor–positive cells. Intranasally administered DNA did not induce airway hyperreactivity (AHR) or any pathology but induced AHR and neutrophilic-eosinophilic inflammation when coadministered with the allergen Alternaria (Alt). Nuc alone induced antiinflammatory/defensive genes, whereas the Nuc-Alt combination increased levels of TNF-α and innate cytokines. The Alt-Nuc phenotype was abolished in Cgas–/–, ALR–/–, Sting–/–, LysMCre:Stingfl/fl, IL7RCre:Rorαfl/fl, and Tnfr2–/– mice. Alt, unexpectedly, played an essential role in the Nuc-induced phenotype. It abrogated Nuc induction of antiinflammatory genes, facilitated Nuc uptake, induced type 2 innate lymphoid cells, which, in the presence of Nuc, produced high levels of TNF-α, and promoted neutrophilic infiltration. We established a paradigm whereby allergens inhibit the antiinflammatory effects of DNA/Nuc and facilitate STING-TNF-α–driven neutrophilic-eosinophilic inflammation in asthma.

Authors

Anand Sripada, Divya Verma, Rangati Varma, Kapil Sirohi, Carolyn Kwiat, Mohini Pathria, Mukesh Verma, Anita Sahu, Vamsi Guntur, Laurie Manka, Brian Vestal, Camille Moore, Richard J. Martin, Magdalena M. Gorska, John Cambier, Andrew Getahun, Rafeul Alam

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Figure 3

Transcriptomic analysis of the mouse models.

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Transcriptomic analysis of the mouse models. (A) Principal component (PC...
(A) Principal component (PC) analysis of transcriptomic changes (RNA-Seq of the lung tissue) in Sal-, Nuc-, Alt-, and Alt-Nuc–treated mice (n = 3). (B) Comparison of differentially expressed genes and up- and downregulated genes between the study groups. (C) Heat map of top 200 genes among the 4 study groups. (D) Top genes selectively induced by Nuc and inhibited by Alt and Alt-Nuc. (E) Validation of increased mRNA (RT-PCR) expression of Bpifa1, Bpifb1, Ddit1, Lactoferrin, and GDF15 in Nuc- versus medium-treated mouse airway epithelial cells. Med, medium. (F–H) Measurement of BPIFA1, GDF15, and BPIFB1 in BAL by ELISA from Sal-, Nuc-, Alt- and Alt-Nuc–treated mice (n = 4–5). (I and J) Top upregulated (I) and downregulated (J) genes (Log2 fold change compared with Sal) among the study groups. (K) Top biological processes driven by the top 50 and top 10 genes from the study groups. GO, Gene Ontology. (L) Comparison of dendritic cell versus macrophage scores for association with the transcriptomes from the study groups. A 2-way ANOVA with Tukey’s multiple comparisons test were used to determine the statistical significance between groups. Data are presented as mean ± SEM. Statistical significance (P values) of difference between the groups are shown above the bar graphs.