Figure 4

Identification and characterization of monocyte subsets in whole blood. Using flow cytometry, monocyte subsets were identified directly in whole blood based on their expression patterns of CD14 and CD16 as described in the Methods section. (a) Gating for the identification of monocyte subsets was based on the successive exclusion of platelets, red blood cells (RBC), granulocytes, and lymphocytes on bivariate scatter plots. The remaining population was discriminated on a CD14 vs. CD16 scatter plot to discriminate three monocyte subsets, classical (CM), intermediate (IM), and non-classical (NCM) monocytes (n = 5). (b) Monocyte subsets were further characterized based on their expression of chemokine receptors CCR2, CX₃CR1, and CCR5 (n = 3). MFI, mean fluorescence intensity. (c) Phenotypic characterization of monocyte subsets based on their expression of CD14, CD16, CCR2, CX₃CR1, and CCR5.