B-Cell and T-Cell Epitopes in Anti-factor VIII Immune Responses

Autor: Arthur R. Thompson, Kathleen P. Pratt
Rok vydání: 2009
Předmět:
Zdroj: Clinical Reviews in Allergy & Immunology. 37:80-95
ISSN: 1559-0267
1080-0549
DOI: 10.1007/s12016-009-8120-7
Popis: Adequate hemostasis is achieved for many hemophilia A patients by infusion of plasma-derived or recombinant factor VIII (FVIII), but unfortunately, a significant subset of patients develop an immune response in which anti-FVIII antibodies, referred to clinically as "inhibitors," interfere with its procoagulant activity. Inhibitors are the subset of anti-FVIII antibodies that bind to surfaces on FVIII (B-cell epitopes) that are important for its proper functioning in coagulation. Less antigenic FVIII molecules may be designed by identifying and then modifying the amino acid sequences of inhibitor B-cell epitopes. Conversely, characterization of these epitopes can yield important information regarding functionally important surfaces on FVIII. The production of inhibitor antibodies is driven by T cells. T cells recognize FVIII as foreign when FVIII-derived peptides bind to major histocompatibility complex (MHC) class II molecules on the surface of antigen-presenting cells. The class II-peptide complexes must then be recognized by T-cell receptors (TCRs). T-cell stimulation requires sustained association of antigen-presenting cells and T cells through formation of a class II-peptide-TCR complex, and peptide sequences that mediate this association are termed "T-cell epitopes." MHC class II tetramers that bind FVIII-derived peptides and recognize antigen-specific TCRs are proving useful in the characterization of human leukocyte antigen-restricted T-cell responses to FVIII.
Databáze: OpenAIRE