Fig. 1: Endogenous presentation of MHC II-restricted mRNA-LNP vaccine antigens is superior to exogenous presentation in vitro and ex vivo.
a Schematic of antigen presentation assay comparing exogenous (exo) and endogenous (endo) conditions, for panels b-d. sp., specific. b, c I-Ab-restricted presentation of NP-45 peptide (b) or HA-16 peptide (c), as measured by fluorescence. Analyzed by paired two-tailed Student’s t-test; p = 9.942 × 10-5 for (c). d Presentation of NP-45 peptide over a range of mRNA doses. Analyzed by linear mixed-effects model, with pathway (exogenous vs. endogenous) and mRNA dose treated as fixed effects and experiment treated as a random effect; significant main effect of the pathway, determined by likelihood ratio test, is shown (p = 3.258 × 10-7). In b-d, each symbol represents the average fluorescence of technical triplicates over background, normalized to the average fluorescence value within an independent experiment. Bars represent mean + SEM of 5 (b) or 3 (c, d) independent experiments. e Schematic of ex vivo antigen presentation assay in panel (g). f Relative abundance of HA mRNA by qPCR among sorted HA+ and HA- APCs, using two different primer sets. Bars indicate mean + SEM of technical triplicates. Representative of 3 independent experiments. Analyzed by unpaired two-tailed Student’s t-test (left, p = 2.307 × 10-6; right, p = 3.907 × 10-6). g Presentation of HA-16 peptide by either HA- or HA+ primary APCs across a range of APC:T cell hybridoma ratios. Bars represent mean + SEM of technical triplicates. Representative of 2 independent experiments. Analyzed by 2-way ANOVA; significant main effect of the APC type (HA- vs. HA+) is shown (p = 5.961 × 10-10). (b–d, f, g) Source data are provided as a Source Data file.
