Figure 6.

CD8 T cell responses are dependent on IFNAR signaling, phagocytes, and B cells

(A) Mice were pretreated with isotype antibodies, anti-CD317 pDC depleting antibody, anti-IFNAR blocking antibody, or clodronate liposomes. μMT mice were used as B cell knockout model. After two or three i.v. immunizations with 10 μg of E7-TriMix mRNA-LNP (weekly intervals), CD8 T cell responses were assessed in blood. (B) IFNAR blocking by i.p. administration of anti-IFNAR antibodies abrogated the E7-specific CD8 T cell response in blood after three immunizations. (C) Depletion of pDCs by i.p. administration of anti-CD317 antibodies had minor negative impact on the percentage of E7-specific CD8 T cells in blood after three immunizations. (D and E) Absence of phagocytes (clodronate-pretreated) (D) or B cells (knockout) (E) strongly reduced the percentage of E7-specific CD8 T cells in blood after two immunizations. In (B), (C), (D), and (E), mean ± SD is shown (n = 4–5). Statistics were assessed by two-way ANOVA with Sidak’s multiple comparison test. ∗p < 0.05, ∗∗∗p < 0.001; ns, not significant.