Summary
In order to define the epitopes recognized by anti-coagulation factor VIII (FVIII)
monoclonal antibodies, we have constructed a recombinant DNA epitope library from
random fragments of the FVIII cDNA. The characterization of 33 different clones producing
recombinant antigens in the expression vector, λgt11, has identified the epitopes
for six different anti-FVIII monoclonal antibodies. The antigenic determinant for
each antibody was defined by the overlapping or shared DNA sequence of multiple immunoreactive
clones. One weak inhibitor of FVIII coagulant activity binds within the gly701 ser750 sequence of the FVIII sequence. An antibody which recognizes the amino-terminus of
FVIII heavy-chain (within trp14 - tyr46) does not inhibit FVIII activity. Two non-neutralizing antibodies both map within
residues asp807 - ser817 while two other non-neutralizing antibodies bind within lys1673 - pro1688. The general usefulness of this strategy for mapping FVIII antigenic determinants
is discussed.
Keywords
Factor VIII - Monoclonal antibodies - Recombinant DNA - Epitope mapping
