LPS priming alters surface expression of HLA-DR and costimulatory molecules in monocytes in a dose-dependent fashion.

PBMCs were cultured with different concentrations of LPS for 24 hours, and monocyte HLA-DR (A), CD86 (B), and CD80 (C) expression was assessed by flow cytometry. Mean (± SEM) data from 3 independent experiments are shown. Dark columns indicate the respective isotypic controls. For the expression of all 3 surface molecules, significant dose dependency was demonstrated by Friedman test (P < .05). Note the different scales for the 3 markers.