Delivering the right message: Challenges and opportunities in lipid nanoparticles-mediated modified mRNA therapeutics-An innate immune system standpoint.

mRNA molecules hold tremendous potential as a tool for gene therapy of a wide range of diseases. However, the main hurdle in implementation of mRNA for therapeutics, the systemic delivery of mRNA molecules to target cells, remains a challenge. A feasible solution for this challenge relies in the rapidly evolving field of nucleic acid-loaded nanocarriers and specifically in the established family of lipid-based nanoparticles (LNPs). Herein, we will discuss the main factors, which determine the fate of modified mRNA (mmRNA)-loaded LNPs in-vivo, and will focus on their interactions with the innate immune system as a main consideration in the design of lipid-based mmRNA delivery platforms.

Cell specific delivery of modified mRNA expressing therapeutic proteins to leukocytes.

Therapeutic alteration of gene expression in vivo can be achieved by delivering nucleic acids (e.g., mRNA, siRNA) using nanoparticles. Recent progress in modified messenger RNA (mmRNA) synthesis facilitated the development of lipid nanoparticles (LNPs) loaded with mmRNA as a promising tool for in vivo protein expression. Although progress have been made with mmRNA-LNPs based protein expression in hepatocytes, cell specificity is still a major challenge. Moreover, selective protein expression is essential for an improved therapeutic effect, due to the heterogeneous nature of diseases. Here, we present a precision protein expression strategy in Ly6c+ inflammatory leukocytes in inflammatory bowel disease (IBD) induced mice. We demonstrate a therapeutic effect in an IBD model by targeted expression of the interleukin 10 in Ly6c+ inflammatory leukocytes. A selective mmRNA expression strategy has tremendous therapeutic potential in IBD and can ultimately become a novel therapeutic modality in many other diseases.