Effect of anti–SNAP-23 and anti–syntaxin 6 antibodies on the cell surface expression of CD63 and CD67 in activated electropermeabilized human neutrophils.

Electropermeabilized cells were incubated with 8 μg/mL anti–SNAP-23 or anti–syntaxin 6 for 3 minutes at room temperature, then were preincubated with 5 μg/mL cytochalasin B for 5 minutes at 37°C, and activated with 1 μmol/L Ca⁺⁺ and 50 μmol/L GTP-γ-S for 10 minutes at 37°C. The cells were then fixed with 1% paraformaldehyde and assayed for CD63 and CD67 antigen expression as described in “Materials and methods.” Untreated electropermeabilized cells (Control) and electropermeabilized cells stimulated with 1 μmol/L Ca⁺⁺ and 50 μmol/L GTP-γ-S for 10 minutes at 37°C (Ca⁺⁺ and GTP) in the absence of anti–SNAP-23 or anti–syntaxin 6 antibodies were run in parallel. The results shown are representative of 3 independent determinations.