Figure 3.

Pharmacology principles of antigen-encoding mRNA. (1) In vitro transcription using linearized DNA plasmid templates with antigen coding sequences. The in vitro transcribed mRNA contains the structures: cap, 5′and 3′ untranslated regions (UTRs), the open reading frame (ORF), and the poly(A) tail. (2) The synthesized mRNA was compounded with cationic liposomes to form an mRNA-LNP complex. (3) Liposomes protect mRNA from RNase degradation and facilitate cellular uptake of mRNA. (4) Release of the mRNA-LNP complex in the cytoplasm. (5) Release of mRNA from liposome complex. (6) mRNA is translated using the host cell’s protein synthesis machinery. (7) terminates translation by mRNAs degradation catalyzed by an external ribozyme. (8) the post-translational modification of the translated protein product depends on the nature of the host cell. (9) protein-derived epitopes can be presented by MHCI and MHCII molecules on the cell surface. (10) the antigenic peptide epitopes degraded by protein products were loaded on the major histocompatibility complex (MHC) and presented to cytotoxic T lymphocytes.