IL-13 decreases susceptibility to airway epithelial SARS-CoV-2 infection but increases disease severity in vivo via eicosanoid signalling.

Background: Treatments available to prevent progression of virus-induced lung diseases, including coronavirus disease 2019 (COVID-19) are of limited benefit once respiratory failure occurs. The efficacy of approved and emerging cytokine signalling-modulating antibodies is variable and is affected by disease course and patient-specific inflammation patterns. Therefore, understanding the role of inflammation on the viral infectious cycle is critical for effective use of cytokine-modulating agents.

Methods: The role of the type 2 cytokine IL-13 on SARS-CoV-2 binding/entry, replication, and host response was investigated in primary HAE cells in vitro and in a model of mouse-adapted SARS-CoV-2 infection in vivo using single-cell and bulk RNA-sequencing approaches. Additionally, the responses were quantified using immunofluorescence, histopathology, immunohistochemistry and LC-MS/MS assays.

Findings: IL-13 protected airway epithelial cells from SARS-CoV-2 infection in vitro by decreasing the abundance of ACE2-expressing ciliated cells rather than by neutralisation in the airway surface liquid or by interferon-mediated antiviral effects. In contrast, IL-13 worsened disease severity in mice; the effects were mediated by eicosanoid signalling and were abolished in mice deficient in the phospholipase A₂ enzyme PLA2G2D.

Interpretation: IL-13-induced inflammation differentially affects multiple steps of COVID-19 pathogenesis. IL-13-induced inflammation may be protective against initial SARS-CoV-2 airway epithelial infection; however, it enhances disease progression in vivo. Blockade of IL-13 and/or eicosanoid signalling may be protective against progression to severe respiratory virus-induced lung diseases.

Funding: Carver Trust COVID-19 Grant; CF Foundation Iowa RDP; NIH 1R01HL163024; K01HL140261; NIH R01AI129269; NIH P01AI060699; NIH Grant P30 DK-54759; Cystic Fibrosis Foundation PEZZUL20A1-KB; Stead Family Foundation.