Maternal diesel particle exposure promotes offspring asthma through NK cell–derived granzyme B
Qian Qian, Bidisha Paul Chowdhury, Zehua Sun, Jerica Lenberg, Rafeul Alam, Eric Vivier, Magdalena M. Gorska
Qian Qian, Bidisha Paul Chowdhury, Zehua Sun, Jerica Lenberg, Rafeul Alam, Eric Vivier, Magdalena M. Gorska
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Research Article Immunology Pulmonology

Maternal diesel particle exposure promotes offspring asthma through NK cell–derived granzyme B

Abstract

Mothers living near high-traffic roads before or during pregnancy are more likely to have children with asthma. Mechanisms are unknown. Using a mouse model, here we showed that maternal exposure to diesel exhaust particles (DEP) predisposed offspring to allergic airway disease (AAD, murine counterpart of human asthma) through programming of their NK cells; predisposition to AAD did not develop in DEP pups that lacked NK cells and was induced in normal pups receiving NK cells from WT DEP pups. DEP NK cells expressed GATA3 and cosecreted IL-13 and the killer protease granzyme B in response to allergen challenge. Extracellular granzyme B did not kill, but instead stimulated protease-activated receptor 2 (PAR2) to cooperate with IL-13 in the induction of IL-25 in airway epithelial cells. Through loss-of-function and reconstitution experiments in pups, we showed that NK cells and granzyme B were required for IL-25 induction and activation of the type 2 immune response and that IL-25 mediated NK cell effects on type 2 response and AAD. Finally, experiments using human cord blood and airway epithelial cells suggested that DEP might induce an identical pathway in humans. Collectively, we describe an NK cell–dependent endotype of AAD that emerged in early life as a result of maternal exposure to DEP.

Authors

Qian Qian, Bidisha Paul Chowdhury, Zehua Sun, Jerica Lenberg, Rafeul Alam, Eric Vivier, Magdalena M. Gorska

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Figure 11

The NK cell pathway in human cell systems.

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The NK cell pathway in human cell systems. (A–H) Human CBMCs were incuba...
(A–H) Human CBMCs were incubated with DEP, HDM, or vehicle (PBS) for 48 hours. To measure NK cell degranulation, PE-labeled anti-CD107a or isotype control IgG, monensin, and brefeldin A were then added for an additional 5 hours. To measure intracellular cytokines in NK cells, monensin and brefeldin A were added for an additional 4 hours. Cells were then stained with eFluor506 (viability) and antibodies for NK cell surface markers ± antibodies for cytokines. (A and C) Gating strategy to define degranulated (A) and cytokine-producing (C) NK cells. Lymphocytes (from the FSC-A vs. SSC-A plot) were gated on singlets and then on live cells (eFluor506–). eFluor506– single lymphocytes were analyzed for CD56 and CD3. NK cells (CD56+CD3–) were analyzed for CD107a (marking degranulated cells; A) or intracellular cytokines (C). (B and D) Representative flow cytometry plots showing anti-CD107a labeling of NK cells (B) and anti-cytokine labeling of NK cells (D) under 3 stimulation conditions (DEP, HDM, and vehicle). (E–H) Percentages of degranulated (CD107a+) NK cells (E), IL-4+ NK cells (F), IL-5+ NK cells (G), and IFN-γ+ NK cells (H) in total live NK cells. n = 8 subjects. (I) Levels of IL25 and IL33 mRNAs in human primary airway epithelial cells treated with vehicle (PBS), human granzyme B ± human IL-13, human IL-13, or an extract of A. alternata. RNA18SN1, 18S ribosomal RNA. Data are pooled from 8 independent experiments (E–H) or are representative of 3 independent experiments (I). Data are shown as mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001, 2-tailed paired t test (E–H); 1-way ANOVA with Tukey’s post hoc test (I).