Figure 1.

Levels of influenza-specific IgG in plasma from JAK3 BMT mice 14 and 56 days after challenge. Mice were infected intranasally with 10^6.8 EID₅₀ of the HKx31 influenza virus, and plasma was collected from the peripheral blood at various time points. Antibody titers were determined by ELISA using the absorbance at 405 nm. No antibody response was detectable for the JAK3 −/− mice 14 days after infection. By contrast, all JAK3 BMT mice showed normal titers of specific antibody at this early time point. Anti-influenza IgG levels also were determined in plasma from JAK3 BMT mice 56 days after challenge. The +/+ BMT and JAK3 BMT mice showed normal levels of circulating virus-specific Ig when compared with untransplanted wild-type mice (+/+). The titers in JAK3 BMT and +/+ BMT mice did not differ significantly between days 14 and 56. Each line represents the antibody titer from an individual mouse.