Abstract：
Immune modulation through the intracellular delivery of nucleoside-modified mRNA to immune cells is an attractive approach for in vivo immunoengineering, with applications in infectious disease, cancer immunotherapy, and beyond. Lipid nanoparticles (LNPs) have come to the fore as a promising nucleic acid delivery platform, but LNP design criteria remain poorly defined, making the rate-limiting step for LNP discovery the screening process. In this study, we employed high-throughput in vivo LNP screening based on molecular barcoding to investigate the influence of LNP composition on immune tropism with applications in vaccines and systemic immunotherapies. Screening a large LNP library under both intramuscular (i.m.) and intravenous (i.v.) injection, we observed differential influences on LNP uptake by immune populations across the two administration routes, gleaning insight into LNP design criteria for in vivo immunoengineering. In validation studies, the lead LNP formulation for i.m. administration demonstrated substantial mRNA translation in the spleen and draining lymph nodes with a more favorable biodistribution profile than LNPs formulated with the clinical standard ionizable lipid DLin-MC3-DMA (MC3). The lead LNP formulations for i.v. administration displayed potent immune transfection in the spleen and peripheral blood, with one lead LNP demonstrating substantial transfection of splenic dendritic cells and another inducing substantial transfection of circulating monocytes. Altogether, the immunotropic LNPs identified by high-throughput in vivo screening demonstrated significant promise for both locally- and systemically-delivered mRNA and confirmed the value of the LNP design criteria gleaned from our screening process, which could potentially inform future endeavors in mRNA vaccine and immunotherapy applications.
摘要：
通过向免疫细胞内递送核苷修饰的mRNA进行免疫调节是体内免疫工程的一种有吸引力的方法。在传染病中的应用，癌症免疫疗法，和超越。脂质纳米颗粒（LNP）已成为有前途的核酸递送平台，但LNP设计标准仍然定义不清，使LNP发现的限速步骤成为筛选过程。在这项研究中,我们采用基于分子条形码的高通量体内LNP筛选方法,研究了LNP组合物在疫苗和全身免疫疗法中的应用对免疫嗜性的影响.在肌内（i.m.）和静脉（i.v.）注射下筛选大型LNP库，我们观察到两种给药途径中免疫群体对LNP摄取的不同影响，了解体内免疫工程的LNP设计标准。在验证研究中，与用临床标准可电离脂质DLin-MC3-DMA(MC3)配制的LNP相比,用于i.m.给药的前导LNP制剂在脾脏和引流淋巴结中显示出大量mRNA翻译,具有更有利的生物分布特征。用于静脉内给药的前导LNP制剂在脾脏和外周血中显示出有效的免疫转染，其中一个前导LNP证明了脾树突状细胞的大量转染，另一个则诱导了循环单核细胞的大量转染。总之,通过高通量体内筛选鉴定的免疫型LNP对局部和系统递送的mRNA显示出显著的希望，并证实了从我们的筛选过程中收集的LNP设计标准的价值。这可能为mRNA疫苗和免疫疗法应用的未来努力提供信息。
