A. Karlsson, Wheat germ agglutinin induces NADPH-oxidase activity in human neutrophils by interaction with mobilizable receptors, INFEC IMMUN, 67(7), 1999, pp. 3461-3468
Wheat germ agglutinin (WGA), a lectin,vith specificity for N-acetylglucosam
ine and sialic acid, was investigated with respect to its ability to activa
te the NADPH-oxidase of in vivo-exudated neutrophils (obtained from a skin
chamber), and the activity was compared to that of peripheral blood neutrop
hils. The exudate cells responded to WGA, by both releasing reactive oxygen
species into the extracellular milieu and producing oxygen metabolites int
racellularly. The peripheral blood cells were unresponsive. To mimic the in
vivo-exuded neutrophils with regards to receptor exposure, peripheral bloo
d neutrophils were induced to mobilize their granules and vesicles to varyi
ng degrees (in vitro priming), prior to challenge with WGA. The oxidative r
esponse to WGA increased with increasing levels of granule mobilization, an
d the receptor(s) could be shown to reside in the secretory vesicles and/or
the gelatinase granules in resting neutrophils. Several WGA-binding glycop
roteins were detected in subcellular fractions containing these organelles.
The extra- and intracellular NADPH-oxidase responses showed differences in
sialic acid dependency, indicating that these two responses are mediated b
y different receptor structures.