Figure 3.
Cellular immune responses following vaccination with LUNAR-COV19
C57BL/6 mice (n = 5 per group) were immunized i.m. with 0.2 μg, 2.0 μg, or 10.0 μg of LUNAR-COV19 or conventional mRNA control and sacrificed at day 7 post-vaccination, and spleens were analyzed for cellular T cell responses by flow cytometry and ELISpot. (A–C) CD8+ (A and B) and CD4+ (C) T effector cells were assessed in vaccinated animals with surface staining for T cell markers and flow cytometry. (D–F) IFNγ+ CD8+ T cells (D and E) and ratio of IFNγ+ IL-4+ CD4+ T cells (F) in spleens of immunized mice were assessed after ex vivo stimulation with PMA/IO and intracellular staining. (G and H) SARS-CoV-2 Spike protein-specific responses to pooled Spike protein peptides were assessed with IFNγ ELISpot assays after vaccination with conventional mRNA controls or LUNAR-COV19. Percentage of CD8+ cells, CD4+ cells, and IFNγ- and IL-4-producing T cells were compared between groups with two-tailed Mann-Whitney U test; ∗0.05 < p < 0.01; ∗∗0.01 < p < 0.001.