Figure 7.

Reduced IL-10 expression during secondary flu responses. (A) WT or IL-10 KO mice were infected with 0.1LD₅₀ A/PR8 (H1N1) and on stated days post primary infection, mice were challenged with 300 LD₅₀ A/Philippines (H3N2) and monitored for weight loss (n=5 mice / group). No primed mice succumbed to secondary challenge. (B) After naïve HNT cell transfer, lung and dLN resident donor cells were assayed for IL-10 production by ICCS on stated days post 0.1LD₅₀ A/PR8 challenge. (C) 2×10⁶ naïve or memory HNT cells (Th1-polarized rested effectors) were transferred to naïve hosts subsequently infected with 1 LD₅₀ A/PR8. On stated days, lungs (n=3 / group) were analyzed for IL-10 message. (D) Lung homogenates (n=3 mice / day) from naïve mice infected with 1 LD₅₀ A/PR8 and from mice primed 60 days previously with A/PR8 and challenged with 300 LD₅₀ A/Philippines were analyzed for IL-10 expression. Data in B-D is representative of 2 independent exp.