Figure 3.

Immunologic mechanism of lipid nanoparticles (LNPs), emerged as the most promising and widely used mRNA delivery platforms. LNPs excel in the efficient delivery of mRNA by merging with the lipid bilayer of early endosomes, thereby facilitating the transport of mRNA into the cytosol. Upon vaccination and uptake by antigen-presenting cells (APCs), the mRNA is transported to the cytoplasm, where it undergoes antigen processing and enters the major histocompatibility complex (MHC) presentation pathway. This results in the presentation of antigens by APCs on MHC class I and II molecules, subsequently activating CD8+ T and CD4+ T cells, respectively. CD4+ T cells also play a role in stimulating antigen-specific B cells, leading to the initiation of a humoral immune response.