title: Screening of mRNA Chemical Modification to Maximize Protein Expression with Reduced Immunogenicity.
abstract: Chemical modification of nucleosides in mRNA is an important technology to regulate the immunogenicity of mRNA. In this study, various previously reported mRNA formulations were evaluated by analyzing in vitro protein expression and immunogenicity in multiple cell lines. For the macrophage-derived cell line, RAW 264.7, modified mRNA tended to have reduced immunogenicity and increased protein expression compared to the unmodified mRNA. In contrast, in some cell types, such as hepatocellular carcinoma cells (HuH-7) and mouse embryonic fibroblasts (MEFs), protein expression was decreased by mRNA modification. Further analyses revealed that mRNA modifications decreased translation efficiency but increased nuclease stability. Thus, mRNA modification is likely to exert both positive and negative effects on the efficiency of protein expression in transfected cells and optimal mRNA formulation should be determined based on target cell types and transfection purposes.
authors.affiliation: Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. suchida@bmw.t.u-tokyo.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Uchida
authors.affiliation: Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. kataoka@bmw.t.u-tokyo.ac.jp.|Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. kataoka@bmw.t.u-tokyo.ac.jp.|Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. kataoka@bmw.t.u-tokyo.ac.jp.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kataoka
authors.affiliation: Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. itaka-ort@umin.net.
authors.forename: Keiji
authors.initials: K
authors.lastname: Itaka
keywords: immunogenicity; mRNA; modification; nuclease-mediated degradation; translation efficiency