Adenoviral vaccine induction of CD8+ T cell memory inflation: Impact of co-infection and infection order
Fig 4
Effect of acute MCMV infection on pre-existing CD8+ D8V+ memory cells.
(A) Mice were first immunized with Ad-lacZ, then infected >50 days later with MCMV. Data are combined from two independent experiments (N = 7–9 mice per group). Peripheral lymphocytes were sampled at 21 days after MCMV infection and stained ex vivo with CD8, CD44 and CD62L. The proportions of effector memory (CD44+ CD62L low), central memory (CD44+CD62L+) and naïve (CD44low CD62L+) was determined. (B) Levels of D8V-specific tetramer population was measured between days 2–7 after infection with MCMV in the blood (N = 4–5 from two independent experiments) and at day 4 in the spleen, bone marrow, lymph nodes and liver. (C) In vivo CTL assay. Splenocytes from mice immunized with Ad-lacZ 45 days previously were isolated and labelled with CFSE then equal numbers of CFSE-labelled splenocytes were adoptively transferred into mice infected with MCMV at day 1 post-infection or a group of uninfected controls. The levels of transferred D8V+ effecter memory cells was followed in the blood over time by ex vivo tetramer staining (N = 6 per group from two independent experiments). To ensure equal numbers of splenocytes were transferred, the percentage of CFSE+CD8+ cells in naïve and MCMV-infected recipients were compared at the indicated time points. (D) The levels of the inflating effector memory D8V tetramer+ population was measured in naïve mice and a group acutely infected with MCMV at the indicated time points. p values were measured by Mann-Whitney test. *p<0.05.