Figure 1.

Nucleoside-modified OspA mRNA-LNP vaccination induces antigen-specific T cell responses in mice

(A) Mice were vaccinated intramuscularly with a single dose of 3 μg of OspA mRNA-LNP or 3 μg of Luc mRNA-LNP or 1 μg of rOspA + alum. Splenocytes were stimulated with an OspA overlapping peptide pool 12 days after immunization, and cytokine production by CD4⁺ and CD8⁺ T cells was analyzed by flow cytometry. Percentages of OspA-specific (B) CD4⁺ and (C) CD8⁺ T cells producing IFN-γ, IL-2, and TNF-α and frequencies of combinations of cytokines produced by (D) CD4⁺ and (E) CD8⁺ T cells are shown. Values from OspA-immunized mice are compared to values from animals immunized with Luc mRNA-LNP or rOspA + alum (B, C, D, and E). Each symbol represents one animal, and data represent mean ± SEM (n = 9–10 mice per group). Data from two independent experiments are shown. Statistical analysis: one-way ANOVA with Bonferroni correction, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001.