Figure 3. Effect of IFN-γ treatment on peripheral blood monocyte PD-L1 expression. (A) Whole blood was treated with 100 ng/mL of LPS, 100 ng/mL of IFN-γ or both. Surface monocyte PD-L1 expression was measured by FACS at 0 h, 6 h and 18 h. Values are mean ± S.E.M. N = 6 at each time point. * P < 0.05, Repeat Measures ANOVA with post-hoc Holms-Sidak test. (B) Representative flow cytometry images with the control group shown in grey and each experimental condition shown without shading. A minimum of 20,000 events acquired for each comparison. MFI, mean fluorescence intensity; LPS, lipopolysaccharide; IFN-γ, interferon-gamma.