Activation of STAT3-mediated ciliated cell survival protects against severe infection by respiratory syncytial virus
Caiqi Zhao, … , Paul H. Lerou, Xingbin Ai
Caiqi Zhao, … , Paul H. Lerou, Xingbin Ai
Published November 1, 2024
Citation Information: J Clin Invest. 2024;134(21):e183978. https://doi.org/10.1172/JCI183978.
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Research Article Infectious disease

Activation of STAT3-mediated ciliated cell survival protects against severe infection by respiratory syncytial virus

Abstract

Respiratory syncytial virus (RSV) selectively targets ciliated cells in human bronchial epithelium and can cause bronchiolitis and pneumonia, mostly in infants. To identify molecular targets of intervention during RSV infection in infants, we investigated how age regulates RSV interaction with the bronchial epithelium barrier. Employing precision-cut lung slices and air-liquid interface cultures generated from infant and adult human donors, we found robust RSV virus spread and extensive apoptotic cell death only in infant bronchial epithelium. In contrast, adult bronchial epithelium showed no barrier damage and limited RSV infection. Single nuclear RNA-Seq revealed age-related insufficiency of an antiapoptotic STAT3 activation response to RSV infection in infant ciliated cells, which was exploited to facilitate virus spread via the extruded apoptotic ciliated cells carrying RSV. Activation of STAT3 and blockade of apoptosis rendered protection against severe RSV infection in infant bronchial epithelium. Lastly, apoptotic inhibitor treatment of a neonatal mouse model of RSV infection mitigated infection and inflammation in the lung. Taken together, our findings identify a STAT3-mediated antiapoptosis pathway as a target to battle severe RSV disease in infants.

Authors

Caiqi Zhao, Yan Bai, Wei Wang, Gaurang M. Amonkar, Hongmei Mou, Judith Olejnik, Adam J. Hume, Elke Mühlberger, Nicholas W. Lukacs, Rachel Fearns, Paul H. Lerou, Xingbin Ai

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Figure 8

Blockade of active STAT3 in RSV-infected adult bronchial epithelium model worsens infection and promotes apoptosis.

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Blockade of active STAT3 in RSV-infected adult bronchial epithelium mode...
(A) Schematic of stattic (20 μM) treatment. Stattic was applied in the bottom chamber of adult ALI cultures 2 hours prior to RSV infection until 2 dpi. Results were shown in B–D. (B) Representative double staining for RSV F (green) protein and c-Casp-3 (red). Blue color is nucleus staining and the overlay of red, green, and blue shows as pink color. (C) The relative level of RSV L gene by RT-qPCR. (D) The relative abundance of RSV F+ and RSV F+c-Casp-3+ cells. (E) Schematic of STAT3 knockdown assay using an inducible lenti-shRNA system. Dox (500 ng/mL) was added to the bottom chamber from day 18. Assays were performed 2 dpi and results were shown in F–H. (F) Representative Western blot analyses to assess STAT3 knockdown efficiency. β-actin was loading control. Each lane represents 1 BSC line. (G) Densitometry measurements of STAT3 levels normalized to β-actin. (H) Representative double staining for RSV F (green) protein and c-Casp-3 (red). Blue color is nucleus staining and the overlay of red, green, and blue shows as pink color. Dotted lines show area indicated in enlarged images. (I) Quantification of the relative abundance of RSV F+ cells and RSV F+c-Casp-3+ cells. Each dot represents 1 donor. **P < 0.01 and ***P < 0.001 calculated by 2-tailed Student’s t test. Scale bars: 50 μm.