Amino acid sequence of a platelet-binding human anti-DNA monoclonal
autoantibody
GW Lampman, B Furie, RS Schwartz, BD Stollar and BC Furie
Division of Hematology-Oncology, New England Medical Center, Boston, MA
02111.
The complete amino acid sequences of the variable regions of the heavy and
light chains of a human IgM monoclonal platelet-binding autoantibody have
been determined. This antibody, HF2-1/17, produced by a human x human
hybridoma prepared from lymphocytes of a patient with systemic lupus
erythematosus and thrombocytopenia, is polyreactive with single-stranded
DNA, synthetic polynucleotides, sulfated carbohydrates, and acidic
glycolipids isolated from platelet membranes. The heavy chain is of the
VHIII subgroup, and the light chain is of the VKI subgroup. The heavy chain
is the expression product of the VH26 germline gene. The light chain bears
significant homology to other immunoglobulins of known primary structure,
including WEA, GAL, HAU, HK101, and DEE. These results suggest that
HF2-1/17 may be an autoantibody derived with little or no modification from
germline genes. A model of the antibody combining site suggests that
arginine 24 and arginine 30 in the light chain (CDR1) interact with a
surface defined by phosphate or sulfate groups of the antigen.
Volume 74,
Issue 1,
pp. 262-269,
07/01/1989
Copyright © 1989 by The American Society of Hematology
