J. Biol. Chem., Vol. 266, Issue 23, 15414-15419, Aug, 1991
Sulfated glycolipids are the platelet autoantigens for human platelet- binding monoclonal anti-DNA autoantibodies
H Murakami, Z Lam, BC Furie, VN Reinhold, T Asano and B Furie
Center for Hemostasis and Thrombosis Research, New England Medical Center, Boston, Massachusetts.
The human monoclonal autoantibody HF2-1/17, produced by a human-human
hybridoma derived from lymphocytes of a lupus patient with
thrombocytopenia, reacts with single stranded DNA and platelets. To
determine the chemical nature of the autoantigen against which this
antibody is directed on platelets, this platelet antigen was purified by
the lipid extraction of sonicated platelets, DEAE-Sephadex chromatography,
and high performance liquid chromatography. The purified glycolipids, a
trace component in platelets, demonstrated high reactivity with the
HF2-1/17 antibody using a competition enzyme-linked immunosorbent assay
system or immunostaining of thin layer chromatograms. The purified
glycolipids co-migrated with bovine sulfatides by thin layer
chromatography. The purified glycolipids contain sulfate and galactose but
not sialic acid or phosphate. Fast atom bombardment-mass spectrometry
revealed these sulfatides to be sulfated monohexyl ceramides. The dominant
species has a molecular weight of 794 while a minor form has a molecular
weight of 812 due to an extra hydroxyl group and loss of a double bond.
These results indicate that the platelet autoantigen against which the
human monoclonal anti-DNA antibody is directed represents a family of novel
monogalactosyl sulfatides.