Department of Plasma Proteins, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, the Netherlands.
Department of Research Facilities, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, the Netherlands.
Haematologica. 2018 Jun;103(6):1083-1092. doi: 10.3324/haematol.2017.179119. Epub 2018 Mar 22.
Formation of microthrombi is a hallmark of acquired thrombotic thrombocytopenic purpura. These microthrombi originate from insufficient processing of ultra large von Willebrand factor multimers by ADAMTS13 due to the development of anti-ADAMTS13 autoantibodies. Several studies have identified the major histocompatibility complex class II alleles HLA-DRB111, HLA-DQB103 and HLA-DQB102:02 as risk factors for acquired thrombotic thrombocytopenic purpura development. Previous research in our department indicated that ADAMTS13 CUB2 domain-derived peptides FINVAPHAR and LIRDTHSLR are presented on HLA-DRB111 and HLA-DRB1*03, respectively. Here, we describe the repertoire of ADAMTS13 peptides presented on HLA-DQ. In parallel, the repertoire of ADAMTS13-derived peptides presented on HLA-DR was monitored. Using HLA-DR- and HLA-DQ-specific antibodies, we purified HLA/peptide complexes from ADAMTS13-pulsed monocyte-derived dendritic cells. Using this approach, we identified ADAMTS13-derived peptides presented on HLA-DR for all 9 samples analyzed; ADAMTS13-derived peptides presented on HLA-DQ were identified in 4 out of 9 samples. We were able to confirm the presentation of the CUB2 domain-derived peptides FINVAPHAR and LIRDTHSLR on HLA-DR. In total, 12 different core-peptide sequences were identified on HLA-DR and 8 on HLA-DQ. For HLA-DR11, several potential new core-peptides were found; 4 novel core-peptides were exclusively identified on HLA-DQ. Furthermore, an analysis was performed using the EpiMatrix and JanusMatrix tools to evaluate the eluted peptides, in the context of HLA-DR, for putative effector or regulatory T-cell responses at the population level. The results from this study provide a basis for the identification of immuno-dominant epitopes on ADAMTS13 involved in the onset of acquired thrombotic thrombocytopenic purpura.
微血栓的形成是获得性血栓性血小板减少性紫癜的一个标志。这些微血栓起源于超大 von Willebrand 因子多聚体由于 ADAMTS13 抗自身抗体的发展而导致的处理不足。几项研究已经确定了主要组织相容性复合体 II 类等位基因 HLA-DRB111、HLA-DQB103 和 HLA-DQB102:02 是获得性血栓性血小板减少性紫癜发展的危险因素。我们部门之前的研究表明，ADAMTS13 CUB2 结构域衍生肽 FINVAPHAR 和 LIRDTHSLR 分别呈现在 HLA-DRB111 和 HLA-DRB1*03 上。在这里，我们描述了呈现在 HLA-DQ 上的 ADAMTS13 肽库。同时，监测了呈现在 HLA-DR 上的 ADAMTS13 衍生肽库。使用 HLA-DR 和 HLA-DQ 特异性抗体，我们从 ADAMTS13 脉冲单核细胞衍生的树突状细胞中纯化 HLA/肽复合物。使用这种方法，我们鉴定了所有 9 个分析样本中 HLA-DR 上呈递的 ADAMTS13 衍生肽；在 9 个样本中的 4 个中鉴定到 HLA-DQ 上呈递的 ADAMTS13 衍生肽。我们能够证实 CUB2 结构域衍生肽 FINVAPHAR 和 LIRDTHSLR 呈现在 HLA-DR 上。总共在 HLA-DR 上鉴定出 12 种不同的核心肽序列，在 HLA-DQ 上鉴定出 8 种。对于 HLA-DR11，发现了几个潜在的新核心肽；仅在 HLA-DQ 上鉴定出 4 个新的核心肽。此外，还使用 EpiMatrix 和 JanusMatrix 工具进行了分析，以评估在人群水平上，洗脱肽在 HLA-DR 背景下作为潜在效应或调节性 T 细胞反应的能力。这项研究的结果为鉴定 ADAMTS13 上参与获得性血栓性血小板减少性紫癜发病的免疫优势表位提供了基础。
