S1PR1, an endothelial-immune influencer

Abstract

Lymphatic dysfunction has been associated with tertiary lymphoid structure (TLS) formation in the mesentery. However, our understanding of TLS formation is mainly focused on inflammatory signaling. Here, Geng et al. (https://doi.org/10.1084/jem.20241799) show that lymphatic endothelial cell (LEC) S1P/S1PR1 signaling plays a role in mesenteric TLS formation in the absence of subclinical inflammation and, importantly, is a key regulator of lymphatic valve development.