Uncoupling in the expression of platelet GP IIb/IIIa in human endothelial
cells and K562 cells: absence of immunologic crossreactivity between
platelet GP IIb and the vitronectin receptor alpha chain [see comments]
N Kieffer, JL Wautier, L Coulombel, M Titeux, MP Wautier, W Vainchenker, C Ruan and J Breton-Gorius
INSERM U91, Hopital Henri Mondor, Creteil, France.
Platelet glycoproteins (GP) IIb and IIIa exist as noncovalently associated
Ca++-dependent heterodimer complexes within the platelet membrane and
express the major platelet alloantigens Leka (Baka) and PIA1 (Zwa), which
are genetic markers of GP IIb and GP IIIa, respectively. Since heterodimers
immunologically related to platelet GP IIb/IIIa have been identified in a
number of nucleated cell types, we tested anti-Leka and anti-PIA1
antiserum, polyclonal anti-platelet GP IIb/IIIa IgG, as well as a panel of
28 monoclonal anti-GP IIb, GP IIIa, or complex dependent anti-GP IIb/IIIa
antibodies on endothelial cells, peripheral blood mononuclear cells, and
the erythroleukemic cells HEL and K562 in order to determine whether
nucleated cell GP IIb/IIIa related proteins and platelet GP IIb/IIIa are
immunologically related. Using immunofluorescence, immunoblotting, and
immunoprecipitation experiments, evidence is presented that (1) the
alloantigen Leka is not expressed in endothelial cells of an individual
whose platelets are of the Leka/PIA1 phenotype, whereas the PIA1
alloantigen is readily detectable in these cells, (2) that in contrast to
HEL cells, which express platelet GP IIb/IIIa and are of the Leka/PIA1
phenotype, platelet GP IIb is immunologically undetectable in
12-O-tetradecanoyl- phorbol-13-acetate (TPA)-treated K562 cells despite the
presence of platelet GP IIIa, and (3) that peripheral blood mononuclear
cells do not express platelet GP IIb or GP IIIa on their cell surface.
Volume 72,
Issue 4,
pp. 1209-1215,
10/01/1988
Copyright © 1988 by The American Society of Hematology
