Exposure to bacterial PAMPs before RSV infection exacerbates innate inflammation and disease via IL-1a and TNF-a
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Published version
Author(s)
Type
Journal Article
Abstract
Respiratory syncytial virus (RSV) can cause severe lower respiratory tract infections. Understanding why some individuals get more serious disease may help with diagnosis and treatment. One possible risk factor underlying severe disease is bacterial exposure before RSV infection. Bacterial exposure has been associated with increased respiratory viral-induced disease severity but the mechanism remains unknown. Respiratory bacterial infections or exposure to their pathogen associated molecular patterns (PAMPs) trigger innate immune inflammation, characterised by neutrophil and inflammatory monocyte recruitment and the production of inflammatory cytokines. We hypothesise that these changes to the lung environment alter the immune response and disease severity during subsequent RSV infection. To test this, we intranasally exposed mice to LPS, LTA or Acinetobacter baumannii (an airway bacterial pathogen) before RSV infection and observed an early induction of disease, measured by weight loss, at days 1–3 after infection. Neutrophils or inflammatory monocytes were not responsible for driving this exacerbated weight loss. Instead, exacerbated disease was associated with increased IL-1α and TNF-α, which orchestrated the recruitment of innate immune cells into the lung. This study shows that exposure to bacterial PAMPs prior to RSV infection increases the expression of IL-1α and TNF-α, which dysregulate the immune response resulting in exacerbated disease.
Date Issued
2024-12
Date Acceptance
2024-08-01
Citation
Mucosal Immunology, 2024, 17 (6), pp.1184-1198
ISSN
1933-0219
Publisher
Elsevier
Start Page
1184
End Page
1198
Journal / Book Title
Mucosal Immunology
Volume
17
Issue
6
Copyright Statement
© 2024 The Authors. Published by Elsevier Inc. on behalf of Society for Mucosal Immunology. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/).
(http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.sciencedirect.com/science/article/pii/S1933021924000837
Publication Status
Published
Date Publish Online
2024-08-09