Lung Epithelial TLR7 is a Factor in Viral Replication and Pathogenesis

TLR7-driven ERK MAP kinase signaling in bronchial epithelial cells increases RSV and influenza replication, while blockade reduces viral replication and RSV eosinophilic/Th2 markers in TLR7 gain-of-function mice.

• Why it matters: Respiratory virus infections cause major illness in infants and the elderly, and the mechanism behind RSV vaccine-associated disease enhancement and immune–virus interactions remains unclear.
• What they did: The study showed TLR7 is expressed in bronchial epithelial cells and detects RSV single-stranded RNA to trigger ERK MAP kinase signaling; blocking TLR7 binding or ERK signaling reduced RSV and influenza replication but not HPIV3.
• The result: RSV and influenza viral loads were higher in mouse and human females than males, and TLR7 gain of function significantly enhanced RSV replication and IL-5–linked eosinophilic/Th2 disease markers.

AI summary of the abstract · may contain errors · not medical advice · read the paper.