Figure 2.

¹⁹F labeling of human NK cells does not alter their surface expression of activating natural cytotoxic receptors and chemokine receptors. (A–G) Human NK cells unlabeled or labeled with 4 mg/mL ¹⁹F (Cell Sense) for 24 h analyzed by flow cytometry for: (A–B) The percent expression in the NK cytotoxic receptors (NCRs) NKp30, NKp46 and NKp44 vs. IgG1 control stains. (A) Illustrates representative dot plots for each NCR and their isotype controls (IgG1) for unlabeled NK cells or NK cells labeled with ¹⁹F. (B) Shows percentage of NKp30, NKp46 and NKp44 on the NK cells (CD3 negative CD56⁺) in five healthy donors. (C–E) The percent expression or (F–G) mean fluorescent intensity (MFI) in the activating receptors DNAM-1 (DNAX Accessory Molecule-1) and NKG2D and in chemokine receptors CX3CR1 and CXCR4 compared to isotype controls in ¹⁹F-labeled or unlabeled NK cells. (D) Percent expression or (G) MFI in the chemokine receptors CX3CR1, CXCR4 or isotype controls after gating on the of CD3neg CD56⁺ NK cells. MFI numbers are indicated within the histograms with color-coded MFIs indicated in the legend and corresponding to the histograms. (E) Shows the percent and (F) MFI in CX3CR1, CXCR4, DNAM-1 and NKG2D on NK cells from five healthy donors labeled or not with ¹⁹F. All gates and histograms are pre-gated on CD3⁻ CD56⁺ NK cells. Bar graph values represent the mean ± SEM tested by two-way ANOVA. Data representative of at least four independent experiments with reproducible results. n.s.= not significant.