Surface marker expression patterns after lipopolysaccharide (LPS) injection. Surface marker expressions were determined on classical monocytes (CM), intermediate monocytes (IM) and non-classical monocytes (NCM) separately. For HLA-DR, the percentage of HLA-DR+ cells was examined as well. Data points are nudged ±0.2 days for better representation of error bars and indicate means ± SEM. *, **, *** and **** indicate p < 0.05, p < 0.01, p < 0.001 and p < 0.0001 compared to t = 0, respectively. n = 6 per time point. MFI, median fluorescence intensity.