FIG 2.

Most immunodominant T cells focused on M1 and NP. (A) Multispecificity T cell lines were raised using IAV-infected P815 cell lysate; 12 to 15 days later, these lines were tested for their reactivity to autologous BLCLs pulsed with individual lysates of P815 cells infected with 11 rVVs encoding single IAV antigens in an IFN-γ ICS assay. BLCLs not pulsed with any lysate (Nil) or pulsed with lysate from uninfected P815 cells (Uninfected) or wild-type (WT) (empty-vector) rVV-infected P815 cells were used as background and specificity controls. Total IAV-specific CD4⁺ T cell responses stimulated by autologous BLCLs pulsed with IAV-infected P815 cell lysate are shown as black bars for easier comparison. The donors' HLA class II alleles are shown in the inset text boxes. (B) The responses of all 8 donors shown in panel A were compiled and statistically analyzed. Statistically significant differences between groups were determined by the Student t test: *, P < 0.05. The error bars indicate the standard error of the mean.