Figure 1.

Strategies used to increase mRNA potency

(A) Poly(A) tail. The ARCA-capped mRNA backbone consisted of an eGFP reporter gene flanked by the 5′ UTR and two copies in tandem of the 3′ UTRs of the human β-globin and ended with a 76, 112, or 148 polyadenylated tail. (B) Synthetic 5′ UTRs. In the mRNA backbone containing the optimal poly(A)¹⁴⁸ tail (148A-mRNA), the 5′ β-globin UTR region was replaced by synthetic sequences with high ribosome loading to generate UTR1 to UTR6 mRNAs. (C) Optimization of IVT mRNA production and purification steps. The standard IVT 148A-mRNA was produced in the presence of ARCA or capped with the vaccinia virus enzyme. Then, the mRNAs could be treated by cellulose chromatography for dsRNA depletion and/or Antarctic phosphatase for the dephosphorylation of 5′PPP-mRNAs.