Inflamed endothelial cells express S1PR1 inhibitor CD69 to induce vascular leak.

ABSTRACT: Inflammation disrupts endothelial barrier function and causes vascular leak into the tissue parenchyma. Sphingosine 1-phosphate receptor-1 (S1PR1) in endothelial cells (ECs) is a key inducer of endothelial junctions and barrier function. We report here that ECs activation by the cytokine TNFα and TLR3 agonist polyinosine/polycytosine (pI:C) induces the lymphocyte activation molecule CD69 via the canonical NFκB pathway. EC CD69 stimulates endocytosis of S1PR1, inhibits its downstream intracellular signaling events and barrier function. Administration of TLR4 or TLR3 agonists or intranasal infection of mouse-adapted influenza virus (H1N1) or coronavirus (MHV-A59) induced CD69 in lung ECs. Adeno-associated virus-mediated overexpression of CD69 in lung EC leads to decreased cell-surface expres

SUBMITTER: Levesque MV 

PROVIDER: S-EPMC12336701 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature