Heart Center, Kaplan Medical Center, Rehovot 76100, Israel.
Cognyxx Ltd., Tel Aviv 6578317, Israel.
Cells. 2022 Nov 29;11(23):3822. doi: 10.3390/cells11233822.
Alpha synuclein (αSyn) misfolding plays a requisite role in the pathogenesis of synucleinopathies. Direct toxicity to neurons, triggering neuroinflammation as well as the spreading and seeding of αSyn pathology are essential pathogenetic underlying mechanisms. Immunotherapy in experimental Parkinson's disease (PD) has been shown to be consistently effective in preclinical models, yet the initial clinical trials with monoclonal antibodies (mAbs) yielded marginal results if any. Aiming to overcome some of the limitation of this approach, we aimed to select an αSyn binding scFv antibody format and test it in multiple experimental PD in vivo models.
We cloned the lead αSyn scFv based on preselection of human phage display libraries of human Fab. The selected of scFv targeting both oligomers and pre-formed fibrils (PFF) of αSyn were tested for their ability to protect neurons from triggered toxicity, influence their uptake to microglia, and accelerate misfolded αSyn degradation. The lead scFv- sMB08, was also tested for its ability to impact αSyn aggregation as well as spreading and seeding.
sMB08 was shown to protect neurons from misfolded αSyn mediated toxicity, promote its intracellular degradation, and to reduce its uptake by microglia. sMB08 exhibited anti-inflammatory properties, including its ability to attenuate adaptive αSyn autoimmunity and ameliorate proinflammatory cytokine expression in brains of mice stereotactically injected with PFF. Employing three experimental models of PD, intranasal treatment with sMB08 attenuated motoric dysfunction and achieved acceptable brain levels by pharmacokinetic analysis, leading to significant preservation of dopaminergic n neurons.
sMB08, a scFv targeting both αSyn oligomers and PFF, due to its small size facilitating paraneural brain penetration and avoidance of nonspecific inflammation, appears as an attractive approach to test in patients with PD by addressing the major mechanisms that mediate misfolded αSyn driven pathology.
α-突触核蛋白（αSyn）错误折叠在突触核蛋白病的发病机制中起必要作用。直接对神经元的毒性，引发神经炎症以及αSyn 病理学的传播和播种是重要的发病机制基础。实验性帕金森病（PD）中的免疫疗法已在临床前模型中显示出一致的有效性，但最初使用单克隆抗体（mAbs）的临床试验结果微不足道。为了克服这种方法的一些局限性，我们旨在选择一种 αSyn 结合 scFv 抗体形式，并在多个实验性 PD 体内模型中进行测试。
我们基于人 Fab 的噬菌体展示文库的预选克隆了该先导αSyn scFv。测试了针对αSyn 寡聚体和预形成纤维（PFF）的 scFv 识别能力，以保护神经元免受触发毒性，影响其被小胶质细胞摄取，并加速错误折叠的αSyn 降解。先导 scFv-sMB08 也被测试了其影响αSyn 聚集以及传播和播种的能力。
sMB08 被证明可以保护神经元免受错误折叠的αSyn 介导的毒性，促进其细胞内降解，并减少小胶质细胞摄取。sMB08 具有抗炎特性，包括其减弱适应性αSyn 自身免疫和改善 PFF 立体定向注射小鼠大脑中促炎细胞因子表达的能力。采用三种 PD 实验模型，sMB08 的鼻内治疗减轻了运动功能障碍，并通过药代动力学分析达到可接受的大脑水平，导致多巴胺能神经元显著保存。
sMB08 是一种靶向 αSyn 寡聚体和 PFF 的 scFv，由于其体积小，有利于神经旁脑穿透并避免非特异性炎症，因此作为一种有吸引力的方法，可以通过解决介导错误折叠αSyn 驱动病理学的主要机制，在 PD 患者中进行测试。
