Low-level expression of CD14 and CD33 on NLCs is an acquired phenotype.

CD14⁺ cells were sorted from blood mononuclear cells of a healthy donor by flow cytometry and then cultured with or without CLL B cells. Adherent cells were harvested on day 14 and analyzed by flow cytometry for expression of CD14 (A), CD33 (B), or HLA-DR (C). The dashed line presents representative fluorescence histograms of cells stained with an isotype control mAb. The thin lines represent the fluorescence histograms of sorted cells prior to culture. The bold lines represent the fluorescence histograms of stained adherent cells that were cultured alone. The shaded histogram provides the fluorescence histograms of stained adherent cells that were cultured with CD19⁺ CLL cells.