TLR4 signaling drives tissue inflammation, Claudin-5 internalization, and vascular barrier breakdown in a mouse model of neonatal meningitis.

TLR4 signaling in non-myeloid cells causes inflammation, Claudin-5 internalization, and vascular barrier breakdown in neonatal E. coli meningitis.

• Why it matters: Understanding the molecular mechanisms of the leptomeningeal response to infection is crucial for developing targeted therapies for neonatal meningitis, which causes high infant morbidity and mortality.
• What they did: The study used conditional gene knockouts, single-nucleus RNA sequencing, and endothelial cell culture to investigate TLR4's role, focusing on its impact on inflammation and vascular permeability in a mouse model.
• The result: Deleting Tlr4 reduced inflammation and prevented vascular leakage, revealing that TLR4 controls an NF-κB-driven transcriptional program that mediates endothelial responses, offering potential therapeutic targets.