Figure 1. FR-β is expressed on circulating human monocytes.

(A) Normal human PBMCs were stained simultaneously with antibodies to FR-β and CD3 (T cells), CD19 (B cells), CD11b (myeloid cells), or CD14 (monocytes), and the percentage of each population that stained for FR-β was determined (percents in upper-right corners). (B) The absence of FR-β on CD14⁻CD66b⁺ neutrophils or other CD14⁻CD66b⁻ granulocytes is shown. Human IgG1 (dashed lines) was used as the isotype IgG control for the anti-FR-β mAb staining (solid lines). Data shown are representative of three independent experiments.