The stimulator of IFN genes (STING) protein senses cyclic dinucleotides released in response to double-stranded DNA and functions as an adaptor molecule for type I IFN (IFNI) signaling by activating IFNI-stimulated genes (ISG). We found impaired T cell infiltration into the peritoneum in response to TNF-α in global and EC-specific STING–/– mice and discovered that T cell transendothelial migration (TEM) across mouse and human endothelial cells (EC) deficient in STING was strikingly reduced compared with control EC, whereas T cell adhesion was not impaired. STING–/– T cells showed no defect in TEM or adhesion to EC, or immobilized endothelial cell–expressed molecules ICAM1 and VCAM1, compared with WT T cells. Mechanistically, CXCL10, an ISG and a chemoattractant for T cells, was dramatically reduced in TNF-α–stimulated STING–/– EC, and genetic loss or pharmacologic antagonisms of IFNI receptor (IFNAR) pathway reduced T cell TEM. Our data demonstrate a central role for EC-STING during T cell TEM that is dependent on the ISG CXCL10 and on IFNI/IFNAR signaling.
Marina Anastasiou, Gail A. Newton, Kuljeet Kaur, Francisco J. Carrillo-Salinas, Sasha A. Smolgovsky, Abraham L. Bayer, Vladimir Ilyukha, Shruti Sharma, Alexander Poltorak, Francis W. Luscinskas, Pilar Alcaide
Exogenous Paracrine IFNI signaling contributes to leukocyte recruitment in response to TNF-α–induced peritonitis and TEM in vitro.