Enterobacter cloacae leukotoxin: modulation of reactive oxidant species generated by neutrophils.
A leukotoxin purified from Enterobacter cloacae culture by saline precipitation, gel chromatography and HPLC was studied as a modulator of reactive oxidant species (ROS) produced by human neutrophils. Chemiluminescence showed that stimulation of ROS was achieved at a low leukotoxin concentration, but ROS production decreased when the toxin was applied at concentrations above 30 microg/mL. Also, the addition of 100 microg toxin/mL significantly reduced the activating effect of phorbol myristate acetate (PMA) and low doses of toxin did not produce an opposite effect toward the stimulation produced by PMA. Normal neutrophils showed a linear correlation between the inverse of ROS production and time, but the kinetic reaction changed when toxins were added to the cells and the ROS formation increased directly with time.
Barnes
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Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende-Ciudad Universitaria, 5000 Córdoba, Argentina.
Paraje
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Orsilles
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Albesa
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D016972:Enterobacter cloacae; D005098:Exotoxins / Q000008:administration & dosage / Q000302:isolation & purification / Q000633:toxicity*; D006801:Humans; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D005098:Exotoxins; D017382:Reactive Oxygen Species; C018579:leukotoxin; D013755:Tetradecanoylphorbol Acetate