Platelet-derived neutrophil adherence-inhibiting factor in humans
K Iwabuchi and T Yamashita
Department of Biochemistry, School of Medicine, Juntendo University, Tokyo,
Japan.
The effect of constituents of human platelets on leukocyte adherence was
examined. Adherence-inhibiting factors (AIFs), which strongly inhibited
neutrophil adherence to glass, were present in both cytosol and granule
fractions of human platelets. On the Superose 6 gel chromatography
(Pharmacia LKB Biotechnology, Uppsala, Sweden), the granular AIF was eluted
as a single active peak (2,600 Kd), whereas cytosolic AIFs were eluted at
two different positions (2,600 and 480 Kd). When platelets were stimulated
by thrombin, granular AIF was released extracellularly without releasing a
cytosolic marker. Using DE32 anion exchange chromatography and Superose 6
gel filtration, granular AIF was completely purified. Sodium dodecyl
sulfate- polyacrylamide gel electrophoresis analysis suggests that granular
AIF consists of two subunits with molecular masses of approximately 340 and
190 Kd. Purified granular AIF inhibited human neutrophil adherence to
glass, plastic, and type IV collagen-coated plastic, whereas it did not
affect monocyte adherence. These results suggest that granular AIF inhibits
neutrophil adherence not only via nonspecific adsorption sites, but also
via type IV collagen receptors.
Volume 76,
Issue 11,
pp. 2368-2373,
12/01/1990
Copyright © 1990 by The American Society of Hematology
