Phevalin inhibits activation of primary human neutrophils.
Addition of synthetic phevalin inhibits activation of primary human neutrophils. By loading PMN with the calcium-sensitive fluorophore Fluo3 and flow cytometry we determined calcium flux upon addition of external stimuli as a proxy for PMN activation. Pre-incubation of PMN with 5 or 10 μM phevalin led to a significant decrease of calcium flux when PMN were stimulated with fMLF, MMK, or dilutions of culture supernatant of S. aureus wild type (0.09%) or a mutant in PSMs (USA300Δαβδ; 0.75%). Depicted is Fluo3 fluorescence units with RPMI-treated PMN set to 0.