背景:抗IgLON5病是一种罕见的神经系统疾病,与针对神经元细胞粘附蛋白的自身抗体相关,IgLON5.人IgLON5抗体的细胞研究表明了抗体介导的发病机理,但是人类IgLON5自身抗体是否可以诱导小鼠的疾病症状还有待证实。此外,抗IgLON5自身抗体对神经元的影响以及体内确切的分子机制仍存在争议.
方法:我们研究了抗IgLON5抗体在体内的作用,并评估了其长期作用。我们使用两个独立的被动转移动物模型,并评估抗体在IgG输注后第1天至第30天的不同时间点对小鼠行为的影响。各种各样的行为,包括运动测试,协调,记忆,焦虑,抑郁症和社会交往得以确立。在终止时,分析脑组织的人IgG,神经元标记,胶质标记物,突触标记和RNA测序。
结果:这些实验表明患者的抗IgLON5抗体在体内诱导进行性和不可逆的行为缺陷。值得注意的是,在新对象识别测试中,CA1平均伽马功率受损支持认知异常.伴随的脑组织研究显示,注射抗IgLON5IgG的小鼠海马中大脑结合的人抗体逐渐增加,在停止注射患者的抗体后30天持续存在。在第30天,注射抗IgLON5IgG的小鼠的海马中的小胶质细胞和星形胶质细胞密度增加。全细胞电压钳记录证明抗IgLON5抗体影响突触稳态。突触蛋白的进一步蛋白质印迹研究显示,在注射抗IgLON5IgG的小鼠中,突触前(突触素)和突触后(PSD95和NMDAR1)表达减少。
结论:总体而言,我们的研究结果表明抗IgLON5抗体具有不可逆的作用,并支持这些抗体在体内的致病性.
BACKGROUND: Anti-IgLON5 disease is a rare neurological disorder associated with autoantibodies against the neuronal cell adhesion protein, IgLON5. Cellular investigations with human IgLON5 antibodies have suggested an antibody-mediated pathogenesis, but whether human IgLON5 autoantibodies can induce disease symptoms in mice is yet to be shown. Moreover, the effects of anti-IgLON5 autoantibodies on neurons and the precise molecular mechanisms in vivo remain controversial.
METHODS: We investigated the effects of anti-IgLON5 antibodies in vivo and evaluated their long-term effects. We used two independent passive-transfer animal models and evaluated the effects of the antibodies on mouse behaviors at different time points from day 1 until day 30 after IgG infusion. A wide range of behaviors, including tests of locomotion, coordination, memory, anxiety, depression and social interactions were established. At termination, brain tissue was analyzed for human IgG, neuronal markers, glial markers, synaptic markers and RNA sequencing.
RESULTS: These experiments showed that patient\'s anti-IgLON5 antibodies induced progressive and irreversible behavioral deficits in vivo. Notably, cognitive abnormality was supported by impaired average gamma power in the CA1 during novel object recognition testing. Accompanying brain tissue studies showed progressive increase of brain-bound human antibodies in the hippocampus of anti-IgLON5 IgG-injected mice, which persisted 30 days after the injection of patient\'s antibodies was stopped. Microglial and astrocyte density was increased in the hippocampus of anti-IgLON5 IgG-injected mice at Day 30. Whole-cell voltage clamp recordings proved that anti-IgLON5 antibodies affected synaptic homeostasis. Further western blot investigation of synaptic proteins revealed a reduction of presynaptic (synaptophysin) and post-synaptic (PSD95 and NMDAR1) expression in anti-IgLON5 IgG-injected mice.
CONCLUSIONS: Overall, our findings indicated an irreversible effect of anti-IgLON5 antibodies and supported the pathogenicity of these antibodies in vivo.