Identification and characterization of a functional receptor for
interferon-gamma on a megakaryocytic cell line
D Monte, J Wietzerbin, V Pancre, G Merlin, SM Greenberg, JP Kusnierz, A Capron and C Auriault
Centre d'Immunologie et de Biologie Parasitaire, Unite mixte INSERM 167-
CNRS 624, Institut Pasteur de Lille, France.
We have previously shown that human interferon-gamma (Hu-IFN-gamma) induces
platelets to become efficient effector cells, capable of killing young
larvae of the parasite Schistosoma mansoni. Recently, binding sites for
IFN-gamma on platelets have been characterized. We show here the presence
of high-affinity receptors for IFN-gamma on the surface of the human
megakaryocytic Dami cell line. Scatchard analysis indicated the presence of
about 11,000 binding sites per cell, with a kd of 3 +/- 0.5 x 10(-10)
mol/L; the apparent molecular weight of the receptor was 90 Kd.
Receptor-bound 125I Hu-recombinant IFN-gamma was rapidly internalized and
degraded when the temperature was increased from 4 degrees C to 37 degrees
C. The half-life of this receptor was about 7 hours, and pretreatment of
cells with IFN-gamma or phorbol myristate acetate had very little effect on
the surface receptor number and no detectable effect on IFN-gamma receptor
messenger RNA (mRNA) expression. The receptor was functional, because 24
hours of treatment with IFN-gamma led to the increase of HLA class I mRNA
expression and to the initiation of HLA class II mRNA expression. These
effects were selective because platelet glycoprotein Ib, IIb, or IIIa mRNA
expression and cell proliferation were unaffected.
Volume 78,
Issue 8,
pp. 2062-2069,
10/15/1991
Copyright © 1991 by The American Society of Hematology
