Fig. 2. Influenza-specific memory T cells are not sufficient to provide efficient protection against heterosubtypic infection.
C57BL/6 and μMT mice were infected or not with 300 EIU of X31, allowed to recover for 4 weeks and then challenged with 1000 EIU of PR8. A. Survival was monitored for 3 weeks after challenge infection. B. Weight loss was measured for 3 weeks following challenge infection. C. Viral titers were measured in the lungs 6 days after challenge infection. D. NP- and PA-specific CD8 T cells were detected in the spleen by flow cytometry on day 6 after challenge infection. The numbers in the panels indicate the frequency of antigen-specific cells in the CD8 population (mean ± standard deviation). The plots are gated on live CD8 T cells. E. The numbers of splenic NP-specific CD8 T cells were calculated on day 6 after challenge infection. There were 5 mice per group in each panel. This experiment was performed 3 times with similar results.
