Miranda Mariarosaria, Hansen Bjarke Endel, Wehbi Batoul, Porcheddu Valeria, Van Alphen Floris P J, Kaijen Paul, Fijnvandraat Karin, Lacroix-Desmazes Sebastien, Van den Biggelaar Maartje, Maillere Bernard, Voorberg Jan, Consortium Educ
Department of Molecular Hematology, Sanquin Research and Landsteiner Laboratory, Amsterdam.
Immudex, Copenhagen, Denmark.
Haematologica. 2025 Jun 1;110(6):1316-1327. doi: 10.3324/haematol.2024.286204. Epub 2024 Dec 12.
The development of neutralizing antibodies (inhibitors) against coagulation factor VIII (FVIII) poses a major challenge in hemophilia A (HA) treatment. The formation of FVIII inhibitors is a CD4+ T-cell-dependent mechanism which includes antigen presenting cells (APC), B- and T-helper lymphocytes. APC present FVIII-derived peptides on major histocompatibility complex class II (MHC-II) to CD4+ T cells. We previously established a mass spectrometry-based approach to delineate the FVIII repertoire presented on HLA-DR and HLA-DQ. In this study, specific attention was directed towards the identification of FVIII peptides presented on HLA-DP. A data-set of naturally processed FVIII peptides was generated by incubating human FVIII with immature monocyte-derived dendritic cells (moDC) from HLA-typed healthy donors. Using this method, we identified 176 to 1,352 different HLA-DP presented peptides per donor, including 26 different FVIII-derived peptides. The most frequently presented peptides derived from the A3 and C2 domains of FVIII. Comparison of the FVIII repertoire presented on HLA-DP with that presented on HLA-DR revealed considerable overlap but also suggested preferential presentation of specific peptides on either HLA-DR or HLA-DP. Fourteen FVIII peptides presented on HLA-DP were synthesized and evaluated for their binding ability to the commonly expressed HLA-DP4 molecule which is highly prevalent in the Caucasian population. Peptide binding studies showed that 7 of 14 peptides competed with a reference peptide to HLA-DP4. Interestingly, an A3 domain-derived peptide bound with high affinity to HLA-DP4, positioning this peptide as a prime candidate for the development of novel peptide-based tolerogenic strategies for FVIII inhibitors.
针对凝血因子VIII（FVIII）的中和抗体（抑制剂）的产生对A型血友病（HA）的治疗构成了重大挑战。FVIII抑制剂的形成是一种CD4 + T细胞依赖性机制，其中包括抗原呈递细胞（APC）、B淋巴细胞和辅助性T淋巴细胞。APC将FVIII衍生的肽呈递在主要组织相容性复合体II类（MHC-II）上给CD4 + T细胞。我们之前建立了一种基于质谱的方法来描绘呈递在HLA-DR和HLA-DQ上的FVIII肽库。在本研究中，我们特别关注鉴定呈递在HLA-DP上的FVIII肽。通过将人FVIII与来自HLA分型健康供体的未成熟单核细胞衍生树突状细胞（moDC）孵育，生成了一组天然加工的FVIII肽数据集。使用这种方法，我们在每个供体中鉴定出176至1352种不同的呈递在HLA-DP上的肽，包括26种不同的FVIII衍生肽。最常呈递的肽来自FVIII的A3和C2结构域。比较呈递在HLA-DP上的FVIII肽库与呈递在HLA-DR上的肽库，发现有相当大的重叠，但也表明特定肽在HLA-DR或HLA-DP上有优先呈递。合成了14种呈递在HLA-DP上的FVIII肽，并评估了它们与在白种人群中高度普遍表达的常见HLA-DP4分子的结合能力。肽结合研究表明，14种肽中的7种与参考肽竞争结合HLA-DP4。有趣的是，一种来自A3结构域的肽与HLA-DP4具有高亲和力结合，使该肽成为开发针对FVIII抑制剂的新型基于肽的耐受性策略的主要候选物。
