Fig 6.

CMV vaccine induces long-term durable CMV-specific immunity: (a) Schematic outline of experimental plan to evaluate long-term durability of immune responses induced by CMV vaccine. HLA A24 expressing mice were immunized on day 0 and then boosted on days 21, 42 and 210 with CMV vaccine. Mice were sacrificed on days 28, 42, 49, 84, 133, 203 and 217 to perform longitudinal analysis of CMV-specific cellular and humoral immunity. (b and d) Ex vivo analysis of CMV-specific CD8⁺ and CD4⁺ T cell responses in HLA A24 expressing mice. Splenocytes from immunized and control mice were stimulated with HLA A24-restricted CD8⁺ T cell peptide epitopes (QYD & AYA) or with CMV gB overlapping peptides in the presence of brefeldin A and then assayed for IFNγ expression using intracellular cytokine assay. (c and e) Frequency of CMV-specific CD8+ and CD4+ T cells following in vitro expansion of antigen-specific T cells. Splenocytes from immunized mice were stimulated with HLA A24-restricted CD8⁺ T cell peptide epitopes (QYD & AYA) or with CMV gB overlapping peptides and cultured for 10 days in the presence of IL-2. On day 10, T cell specificity was assessed using intracellular cytokine assay. *P < 0.05; **P < 0.01; ***P < 0.001 by Welch’s t test. Statistics are indicated in comparison with control group. If statistics are not indicated, then the comparison was not significant (ns).