Role of T-cells for D1701-V-HAh5n-induced protection.

<p>BALB/c mice were immunized twice (V1 and V2) with 10⁷ pfu of D1701-V-HAh5n and depletion was performed during immunization <b>(A)</b>, during challenge <b>(B)</b> or during immunization and challenge <b>(C)</b>. Challenge (Ch) was performed with 20× MLD50 strain MB1 and mice were monitored during 14 days after challenge. Survival of mice (<i>n</i> = 8) is shown in panels a, the mean percentage of body weight (bars indicate SEM) is demonstrated in panels b. Mice were sacrificed after having dropped more than 25% of their original body weight. Panels c schematically depict the days of <i>in vivo</i> depletion of CD4-positive, CD8-positive or both CD4- and CD8-positive T-cell subset as described in <i>Material and Methods</i>. For control, challenge infection of immunized non-depleted animals or non-immunized mice (ni) was also performed.