Figure 3. Intravenous but not intranasal post-exposure MVA immunization activates NK and T cells.

C57BL/6 mice were infected intranasally with 3×10⁴ TCID₅₀ of ECTV. Mice were left untreated or immunized after 3 days with 5×10⁷ TCID₅₀ of MVA either intravenously or intranasally. 1 day after MVA immunization mice received an injection of 250 µg BFA and 6 hours later spleens were removed, stained and analyzed by FACS. (A) Representative contour plots are shown for NK cells (NK1.1⁺ CD3⁻) and CD8 T cells (NK1.1⁻ CD3⁺ CD8⁺). The frequency of GranzymeB⁺CD69⁺ NK cells (upper panel) and CD8 T cells (lower panel) is shown in (B). (C) Representative histograms are shown for CD4 T cells (NK1.1⁻ CD3⁺ CD4⁺). The frequency of CD69^high CD4 T cells is shown in (D). Data are means ± SD of 4–5 mice per group. The experiment was repeated once with a similar outcome.