In vivo expression of LUC after intradermal injection of c-srRNA
(A) Schematic diagram of c-srRNA structure. Non-structural proteins (nsP1-nsP4) encode a replica of Venezuelan equine encephalitis virus (VEEV). c-srRNA is produced by in vitro transcription and has a form of mRNA with 5′-Cap and 3′-polyA sequence. No modified nucleosides.
(B–D) mRNAs, mRNA-LUC (CleanCap Fluc mRNA [5-methoxyuridine], Tri-Link L-7202) or c-srRNA1-LUC, were prepared as naked RNAs, without LNP or other transfection reagents, in lactated Ringer’s solution. Five microgramsof mRNAs was injected intradermally into a single site on the right hind limb of CD-1 outbred mice (Day 0). Luciferase activity was visualized and quantitated by using a bioluminescent imaging system, AMI HTX (Spectral Instruments Imaging, Tucson, AZ) from Day 1 through Day 26. (B) Representative pictures of mice that received the intradermal injection of mRNA-LUC. (C) Representative pictures of mice that received the intradermal injection of c-srRNA1-LUC. (D) Changes in LUC activities over time for the mice are shown in (B) and (C). Luciferase activity was represented as average radiance.