Miller L, Weissmüller S, Ringler E, Crauwels P, van Zandbergen G, Seitz R, Waibler Z
Zoe Waibler, Junior Research Group "Novel Vaccination Strategies and Early Immune Responses", Paul-Ehrlich-Institut, 63225 Langen, Germany, Tel.: +49 6103 77 5009, Fax: +49 6103 77 1253, E-mail:
Thromb Haemost. 2015 Aug;114(2):268-76. doi: 10.1160/TH14-09-0789. Epub 2015 May 7.
Treatment of haemophilia A by infusions of the clotting factor VIII (FVIII) results in the development of inhibitors/anti-drug antibodies in up to 25 % of patients. Mechanisms leading to immunogenicity of FVIII products are not yet fully understood. Amongst other factors, danger signals as elicited upon infection or surgery have been proposed to play a role. In the present study, we focused on effects of danger signals on maturation and activation of dendritic cells (DC) in the context of FVIII application. Human monocyte-derived DC were treated with FVIII alone, with a danger signal alone or a combination of both. By testing more than 60 different healthy donors, we show that FVIII and the bacterial danger signal lipopolysaccharide synergise in increasing DC activation, as characterised by increased expression of co-stimulatory molecules and secretion of pro-inflammatory cytokines. The degree and frequency of this synergistic activation correlate with CD86 expression levels on immature DC prior to stimulation. In our assay system, plasma-derived but not recombinant FVIII products activate human DC in a danger signal-dependent manner. Further tested danger signals, such as R848 also induced DC activation in combination with FVIII, albeit not in every tested donor. In our hands, human DC but not human B cells or macrophages could be activated by FVIII in a danger signal-dependent manner. Our results suggest that immunogenicity of FVIII is a result of multiple factors including the presence of danger, predisposition of the patient, and the choice of a FVIII product for treatment.
通过输注凝血因子VIII（FVIII）治疗甲型血友病，高达25%的患者会产生抑制剂/抗药物抗体。导致FVIII产品具有免疫原性的机制尚未完全明确。在其他因素中，感染或手术引发的危险信号被认为起到了一定作用。在本研究中，我们聚焦于在应用FVIII的背景下，危险信号对树突状细胞（DC）成熟和激活的影响。将人单核细胞来源的DC单独用FVIII处理、单独用危险信号处理或两者联合处理。通过检测60多名不同的健康供体，我们发现FVIII与细菌危险信号脂多糖协同作用，增强DC激活，其特征为共刺激分子表达增加和促炎细胞因子分泌增加。这种协同激活的程度和频率与刺激前未成熟DC上的CD86表达水平相关。在我们的检测系统中，血浆来源而非重组FVIII产品以危险信号依赖的方式激活人DC。进一步测试的危险信号，如R848，与FVIII联合时也能诱导DC激活，尽管并非在每个测试供体中都如此。在我们的实验中，人DC而非人B细胞或巨噬细胞可被FVIII以危险信号依赖的方式激活。我们的结果表明，FVIII的免疫原性是多种因素共同作用的结果，包括危险信号的存在、患者的易感性以及用于治疗的FVIII产品的选择。
