Therapeutic Potential of Shark Anti-ICOSL VNAR Domains is Exemplified in a Murine Model of Autoimmune Non-Infectious Uveitis.
Therapeutic Potential of Shark Anti-ICOSL VNAR Domains is Exemplified in a Murine Model of Autoimmune Non-Infectious Uveitis.
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DOI：
10.3389/fimmu.2017.01121
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发表时间：
2017
影响因子：
7.3
通讯作者：
Porter A
中科院分区：
文献类型：
--
作者：
Kovaleva M;Johnson K;Steven J;Barelle CJ;Porter A
诱导型共刺激配体（ICOSL）通过与诱导型共刺激分子（ICOS）相互作用，在T细胞活化中发挥重要作用。完全T细胞活化的抑制可以通过阻断这种相互作用来实现，并且已被证明是在自身免疫和炎症模型中改善疾病的有效手段。在这项研究中，我们证明了一种新型的抗ICOSL抗原结合单域来源于鲨鱼（VNARs），以有效地减少炎症的非感染性葡萄膜炎的小鼠模型的能力。在最初的选择中，识别人ICOSL的特异性VNAR从免疫的护士鲨噬菌体展示文库中分离，并在一系列抗原选择性和体外生物测定筛选中鉴定其性能后鉴定前导结构域。在基于细胞的阻断测定中的高效力表明它们作为适合于进一步治疗开发的新型结合剂的潜力。为了检验这一假设，从相同的噬菌体展示文库中分离替代抗小鼠IC 0 SL VNAR结构域，并通过在结合和IC 0 S/IC 0 SL阻断实验中筛选来选择前导VNAR克隆。将在基于细胞的ICOS/ICOSL相互作用阻断中具有最高效力的VNAR结构域与人IgG 1的Fc部分融合，并在光感受器间类维生素A结合蛋白诱导的葡萄膜炎的小鼠模型中进行体内测试。与未处理的对照动物相比，全身注射的抗mICOSL VNAR Fc导致处理的小鼠中的炎症显著减轻。这种方法抑制疾病进展的程度与阳性皮质类固醇对照环孢菌素A相同，降低了临床和组织病理学评分。这些结果代表了VNAR结合结构域在相关疾病临床模型中的功效的首次证明，并突出了VNAR用于治疗自身炎性病症的潜力。
Induced costimulatory ligand (ICOSL) plays an important role in the activation of T cells through its interaction with the inducible costimulator, ICOS. Suppression of full T cell activation can be achieved by blocking this interaction and has been shown to be an effective means of ameliorating disease in models of autoimmunity and inflammation. In this study, we demonstrated the ability of a novel class of anti-ICOSL antigen-binding single domains derived from sharks (VNARs) to effectively reduce inflammation in a murine model of non-infectious uveitis. In initial selections, specific VNARs that recognized human ICOSL were isolated from an immunized nurse shark phage display library and lead domains were identified following their performance in a series of antigen selectivity and in vitro bioassay screens. High potency in cell-based blocking assays suggested their potential as novel binders suitable for further therapeutic development. To test this hypothesis, surrogate anti-mouse ICOSL VNAR domains were isolated from the same phage display library and the lead VNAR clone selected via screening in binding and ICOS/ICOSL blocking experiments. The VNAR domain with the highest potency in cell-based blocking of ICOS/ICOSL interaction was fused to the Fc portion of human IgG1 and was tested in vivo in a mouse model of interphotoreceptor retinoid-binding protein-induced uveitis. The anti-mICOSL VNAR Fc, injected systemically, resulted in a marked reduction of inflammation in treated mice when compared with untreated control animals. This approach inhibited disease progression to an equivalent extent to that seen for the positive corticosteroid control, cyclosporin A, reducing both clinical and histopathological scores. These results represent the first demonstration of efficacy of a VNAR binding domain in a relevant clinical model of disease and highlight the potential of VNARs for the treatment of auto-inflammatory conditions.