Updated project metadata. The circulating proteome offers insight into the stage and severity of the immune response. To characterise the release kinetics and cellular source of plasma protein changes, serial samples were obtained from healthy volunteers (n=10, 3 time-points) injected with low-dose endotoxin (LPS) and analysed using date-independent acquisition (DIA) MS. The systemic and vascular inflammatory responses were compared using LPS-induced endotoxemia models in mice.