Figure 4.

Effects of piscidin on the expression of Fpr2 on the surface of neutrophils. Bone marrow neutrophils isolated from the femurs of WT mice were exposed to 1 μm fMLF, 1 μm P1/3 (P1/3), or 1 μm P1/3 + 1 μm Cu²⁺. The cells were then treated with anti-CD16/32 mAb to eliminate nonspecific binding of mAb to FcγII/IIIR, followed by incubation with an anti-mouse Fpr2 mAb and a goat anti-mouse IgG conjugated with PE. Flow cytometry was performed to analyze the cells. The experiments were performed three times in triplicate, with a representative set of triplicates being shown and the S.D. calculated using the data from the triplicates. In each panel for the chosen representative set, the expression is indicated as a percentage relative to the PBS/Anti-Fpr2/PE control that was obtained over the triplicates. Incubation with fMLF significantly reduced the expression of Fpr2 on the neutrophils (p < 0.05). Both P1 and P3 also significantly reduced Fpr2 expression on the cell surface (p < 0.05). Conjugation with Cu²⁺ slightly reduced the capacity of P1 and P3 to down-regulate Fpr2 on the surface of neutrophils, but the change was not statistically significant.