Low molecular weight peptides restore the procoagulant activity of factor VIII in the presence of the potent inhibitor antibody ESH8.
Following repeated administration of factor VIII (FVIII), a significant number of hemophilia A patients develop antibodies (Abs), inhibiting the procoagulant activity of infused FVIII. We have designed an approach based on the blocking of the deleterious activity of these Abs by peptide decoys mimicking the anti-FVIII Ab epitopes. Here, the well characterized inhibitory monoclonal Ab ESH8 served as a model. Several phage peptide libraries were screened for specific binding to ESH8. Seven constrained dodecapeptide sequences were obtained. Six sequences carried the consensus motif, hydrophobic-(Y/F)GKTXL. This motif showed a certain similarity with the (2231)QVDFQKTMKV(2240) sequence of the C(2) domain. In the seventh sequence, YCNPSIGDKNCR, the residues GDKN are similar to the sequence (2267)DGHQ(2270). Upon inspection of the C(2) domain crystallographic structure, the two stretches QVDFQKTMKV and DGHQ appeared close together in space and might constitute a discontinuous epitope. Corresponding synthetic peptides were able to inhibit the binding of ESH8 to FVIII in a specific and dose-dependent manner. Moreover, the ability of the selected peptides to neutralize the inhibitory activity of ESH8 was demonstrated in functional tests as well as in vivo in a murine model of hemophilia A. This study demonstrates the potential of this approach to neutralize the activity of potent inhibitory Abs.
Villard
Sylvie
S
Unité Mixte de Recherche, CNRS 5094, Faculté de Pharmacie, BP 14491, 15 Avenue Charles Flahault, 34093 Montpellier Cedex 5, France.
Piquer
Dominique
D
Raut
Sanjee
S
Léonetti
Jean-Paul
JP
Saint-Remy
Jean-Marie
JM
Granier
Claude
C
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D005169:Factor VIII / Q000737:chemistry* / Q000378:metabolism*; D006467:Hemophilia A / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013917:Thrombin / Q000378:metabolism; D013997:Time Factors
D000911:Antibodies, Monoclonal; D000939:Epitopes; D019151:Peptide Library; D010455:Peptides; D005169:Factor VIII; D013917:Thrombin; D003545:Cysteine