Efficient induction of superoxide release from human neutrophils by the galactoside-specific lectin from Viscum album.
The immunomodulatory galactoside-specific lectin from Viscum album (VAA) induces superoxide anion (O2.-) release from human neutrophils. Among twelve tested lectins, VAA, has the highest activity, clearly surpassing the effect of the human beta-galactoside-specific lectin (galaptin). Its reactivity is blocked in the presence of lactose and is strictly dependent on the carbohydrate-binding B-subunit. The toxic A-subunit of the lectin does not elicit a response. The VAA-induced respiratory burst is less sensitive to addition of adenosine and theophylline than the concanavalin A-mediated reaction. Other modulators like amiloride (up to 100 microM), trifluoperazine and N-ethylmaleimide reveal less pronounced differences, and indomethacin, colchicine (up to 100 microM) as well as cytochalasin B act as stimulators of lectin-induced O2.- release from neutrophils. The O2.- production in the presence of small concentrations of VAA (0.1-20 micrograms/ml) is increased by addition of N-formylmethionyl-leucyl-phenylalanine (FMLP), phorbol 12-myristate 13-acetate (PMA) or digitonin, respectively, whereas concanavalin A (Con A) or wheat germ agglutinin (WGA) fail to affect the VAA-dependent extent of the respiratory burst. These results substantiate that the VAA-induced O2.- release from human neutrophils can be enhanced by other classes of inductors.
Institut für Pharmazeutische Chemie, Philipps-Universität Marburg.
A V
AV
Timoshenko
H J
HJ
Gabius
D000241:Adenosine / Q000494:pharmacology; D003208:Concanavalin A / Q000494:pharmacology; D037161:Galectins; D006388:Hemagglutinins / Q000494:pharmacology; D006801:Humans; D037102:Lectins / Q000494:pharmacology*; D008297:Male; D014784:Mistletoe; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D037121:Plant Lectins; D010946:Plants, Medicinal; D016897:Respiratory Burst / Q000187:drug effects*; D013481:Superoxides / Q000378:metabolism*; D013806:Theophylline / Q000494:pharmacology
D037161:Galectins; D006388:Hemagglutinins; D037102:Lectins; D037121:Plant Lectins; D003208:Concanavalin A; D013481:Superoxides; D013806:Theophylline; D000241:Adenosine