Figure 8. TACI^–/– mice have reduced Ab-mediated protection.

(A) HI assay with sera from WT and TACI^–/– mice collected 3 months after infection with influenza virus PR8. (B) Sera from WT and TACI^–/– mice (n = 8–9 mice/group) 2–3 months after infection were tested for binding to PR8 (dashed line) and SW (solid line) virus by ELISA. As a control, sera from naive mice are shown at a dilution of 1:200. (C) Two to 3 months after primary infection with influenza virus PR8, WT and TACI^–/– mice were challenged with 2,000 TCID₅₀/30 μl of SW virus, and lungs were assayed for viral titers 5 days later. (D) Viral titers in lungs from PR8-infected WT and TACI^–/– mice 5 days after challenge with SW virus. Dotted line represents limit of detection for this assay. Data with mean ± SEM summarize 2 independent experiments. ***P < 0.001.