Figure 2. The proliferative capacity of early life induced GP33 specific CD8+ T cells matches that of adult primed cells.

C57BL/6 infant mice were vaccinated with 2 × 10⁶ or 2 × 10⁷ pfu Ad-liGP s.c in the foot pad and 60 days later the mice were challenged i.p with 2 × 10⁶ pfu VV-GP. Mice, vaccinated with 2 × 10⁷ pfu Ad-liGP as adults (Ctrl) and similarly challenged, were used as positive controls, and unvaccinated, vaccinia challenged mice were used to illustrate the unprimed/primary VV-GP induced response. Six days post challenge IFN-γ producing CD8+ T cells were enumerated by flow cytometry following ex vivo peptide stimulation with GP_33-41. CD8+ T-cell numbers with and without VV-GP challenge are depicted; the results regarding unchallenged mice are the same as shown in Fig. 1. Each dot represents an individual animal, and the stippled line background. The depicted data are pooled from two independent experiments. *p < 0.05.