A human monoclonal autoantibody recognizes a neoantigen on glycoprotein
IIIa expressed on stored and activated platelets
DJ Nugent, TJ Kunicki, C Berglund and ID Bernstein
We prepared a heterohybrid cell line that secretes a human IgM monoclonal
autoantibody that recognizes an antigen found on thrombin- activated or
stored platelets. The surface expression of the epitope recognized by this
autoantibody, 5E5, increases with time as platelets age in vitro,
suggesting that it may represent a senescence or activation-specific
antigen. 5E5 binds to the purified platelet membrane glycoprotein (GP)
IIb-IIIa complex in an enzyme-linked immunosorbent assay (ELISA). In an
immunoblot technique, 5E5 binds to a protein with an apparent mol wt of
95,000, which is identical to that of GPIIIa under nonreduced conditions.
In crossed immunoelectrophoresis (CIE), the predominant antigen recognized
by 5E5 is contained in the GPIIb-IIIa precipitin arc. An additional
precipitin arc recognized by 5E5 is often observed only on gels derived
from lysates of platelets stored under blood bank conditions for greater
than 3 days. These findings illustrate the usefulness of human monoclonal
antibodies for the identification of membrane neoantigens expressed as a
result of platelet activation or revealed as platelets age in vitro.
Volume 70,
Issue 1,
pp. 16-22,
07/01/1987
Copyright © 1987 by The American Society of Hematology
