Repurposing an endogenous human mRNA transfer system as a gene therapy tool

该项目的目的是绘制出一个自然发生的系统的可行性和性能的mRNA转移在人类时，重新用于提供重组RNA有效载荷。该系统包括一个单一的蛋白质，在翻译时，与其编码的mRNA结合，然后形成一个颗粒，隔离该mRNA，之后，颗粒被囊泡包裹，囊泡在细胞释放和病毒释放之前出芽成多泡体（MVB）。例如转移到靶细胞，其中有效载荷mRNA被释放用于随后的翻译。这是由用于基因转移的病毒载体的免疫原性引起的。Kumin et al.（2021）报道，在149项2021年AAV基因治疗临床试验中，平均有35%与治疗后出现的严重不良事件相关，本项目将对蛋白X mRNA进行修饰，以测试其整合重组RNA元件的能力。将检测不同大小和序列的插入元件通过工程化蛋白X系统从包装细胞转移至靶细胞的能力。预计蛋白-X系统的免疫原性将显著低于基于病毒的系统。

This project aims to map out the feasibility and performance of a naturally-ocurring system for mRNA transfer in humans when repurposed to deliver recombinant RNA payloads. The system involves a single protein that, upon translation, associates with its encoding mRNA then forms a particle that sequesters that mRNA, after which the particle is enveloped within vesicles that bud into a multivesicular body (MVB) before cellular release and virus-like transfer to target cells in which the payload mRNA is released for subsequent translation.Gene therapy approaches have recently faced challenges due in part to adverse effects arising from the immunogenicity of the viral vectors used for tgene transfer. Kumin et al. (2021) report that, on average, 35% of 149 2021 AAV gene therapy clinical trials were associated with treatment-emergent serious adverse events.In this project the Protein X mRNA will be modified to test its capacity to incorporate recombinant RNA elements. Inserted elements of differing size and sequence will be tested for their ability to be transferred from packaging cells to target cells via the engineerred Protein X system. It is anticipated that the immunogenicity of a Protein-X system will be significantly lower than that of virus-based systems.