Fig 1. Gating strategy for studying monocyte subsets and differential expression of PD-1 in monocyte subsets.
(A) Gating strategy of monocyte subsets. The CD45-positive monocytes (“monocytic gate”) together with adjacent lymphocytes were further analyzed. The cells were then gated to exclude CD14-HLA-DR- NK cells and finally divided into CD14++CD16- (classical), CD14++CD16+ (intermediate) and CD14+CD16++ (non-classical) monocytes. The absolute numbers of monocyte subsets were estimated based on acquired bead count (“beads gate” on plot no 1). (B) PD-1 expression on monocyte subsets. PD-1 expression pattern is shown on each of the monocyte subsets (classical, intermediate and non-classical subsets) in a patient analyzed on 5th DOL, a patient that developed LOS, and a patient with septic shock.