Purpose

Age-related macular degeneration (AMD), the leading cause of blindness in western populations, is associated with an overactive complement system, and an increase in circulating antibodies against certain epitopes, including elastin. As loss of the elastin layer of Bruch's membrane (BrM) has been reported in aging and AMD, we previously showed that immunization with elastin peptide oxidatively modified by cigarette smoke (ox-elastin), exacerbated ocular pathology in the smoke-induced ocular pathology (SIOP) model. Here we asked whether ox-elastin peptide-based immunotherapy (PIT) ameliorates damage.

Methods

C57BL/6J mice were injected with ox-elastin peptide at two doses via weekly subcutaneous administration, while exposed to cigarette smoke for 6 months. FcγR^−/− and uninjected C57BL/6J mice served as controls. Retinal morphology was assessed by electron microscopy, and complement activation, antibody deposition and mechanisms of immunological tolerance were assessed by Western blotting and ELISA.

Results

Elimination of Fcγ receptors, preventing antigen/antibody-dependent cytotoxicity, protected against SIOP. Mice receiving PIT with low dose ox-elastin (LD-PIT) exhibited reduced humoral immunity, reduced complement activation and IgG/IgM deposition in the RPE/choroid, and largely a preserved BrM. While there is no direct evidence of ox-elastin pathogenicity, LD-PIT reduced IFNγ and increased IL-4 within RPE/choroid. High dose PIT was not protective.

Conclusions

These data further support ox-elastin role in ocular damage in part via elastin-specific antibodies, and support the corollary that PIT with ox-elastin attenuates ocular pathology. Overall, damage is associated with complement activation, antibody-dependent cell-mediated cytotoxicity, and altered cytokine signature.

中文翻译：

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基于肽的针对氧化弹性蛋白的免疫疗法可改善烟雾引起的眼损伤小鼠模型的病理学

 目的

年龄相关性黄斑变性 (AMD) 是西方人群失明的主要原因，它与补体系统过度活跃以及针对某些表位（包括弹性蛋白）的循环抗体增加有关。由于在衰老和 AMD 中已经报道了布鲁赫膜弹性蛋白层 (BrM) 的损失，我们之前表明，用香烟烟雾氧化修饰的弹性蛋白肽 (ox-elastin) 进行免疫，会加剧烟雾诱发的眼部病理学中的眼部病理学。 SIOP）模型。在这里，我们询问基于氧化弹性蛋白肽的免疫疗法 (PIT) 是否可以减轻损伤。

 方法

C57BL/6J 小鼠每周皮下注射两次剂量的氧化弹性蛋白肽，同时暴露于香烟烟雾中 6 个月。 FcγR ^−/−和未注射的 C57BL/6J 小鼠作为对照。通过电子显微镜评估视网膜形态，通过蛋白质印迹和 ELISA 评估补体激活、抗体沉积和免疫耐受机制。

 结果

消除 Fcγ 受体，防止抗原/抗体依赖性细胞毒性，防止 SIOP。接受低剂量氧化弹性蛋白 (LD-PIT) PIT 的小鼠表现出体液免疫降低、补体激活和 RPE/脉络膜中 IgG/IgM 沉积减少，并且大部分 BrM 得到保留。虽然没有直接证据表明氧化弹性蛋白具有致病性，但 LD-PIT 会减少 RPE/脉络膜内的 IFNγ 并增加 IL-4。高剂量 PIT 没有保护作用。

 结论

这些数据进一步支持了氧化弹性蛋白在眼部损伤中的作用，部分是通过弹性蛋白特异性抗体，并支持了氧化弹性蛋白 PIT 可减轻眼部病理的推论。总体而言，损伤与补体激活、抗体依赖性细胞介导的细胞毒性和细胞因子特征改变有关。