IL-1β Upregulates PD-L1 in Small Extracellular Vesicle of Endothelial Origin

Programmed death ligand 1(PD-L1) is of significant importance in the regulation of immune cells, and its levels increase in response to inflammation in HUVECs. In this letter, we examined the expression of PD-L1 on small extracellular vesicles (sEVs) in human umbilical vein endothelial cells (HUVECs) and investigated its modulation in response to interleukin-1β (IL-1β), a key player in the immune response and is involved in the pathogenesis of several diseases. We found that stimulation of HUVECs with IL-1β resulted in the release of a higher number of sEVs-PD-L1positive. This result provides significant insights into the potential role of sEVs-PD-L1positive in regulating inflammatory and immune responses in the vascular endothelium.