Code from: A distinct antigen presentation pathway drive potent T-cell immunity in lipid nanoparticle-based mRNA vaccines

Retrogenic mice were immunized with OVA mRNA-LNP or OVA protein + poly I/C, and SIINFEKL/Kb tetramer-positive CD8 T cells were analyzed on day 14. TCR sequencing analysis showed that the number of TCR clonotypes was markedly reduced in SIINFEKL/Kb tetramer-positive CD8 T cells compared to total CD8 T cells before immunization.

Principal component analysis revealed a marked similarity in the composition of OVA peptide-reactive TCRs between mice immunized with OVA mRNA-LNP and those receiving OVA protein + poly I/C. These results showed similar TCR repertoires induced by OVA mRNA-LNP and OVA + poly I/C, suggesting that the robust expansion of CD8 T cells by mRNA-LNP is primarily due to differences that are quantitative rather than qualitative compared to antigen protein and conventional adjuvants.