Fig 8. Lung T cell profile of aged seropositive mice following immunization with different RSV F formulations and post challenge with RSV A2.

12 months old mice were i.n. immunized with RSV A2 (10⁶ PFU) at day 0 and RSV B (10⁵ PFU) at day 60. Aged seropositive mice were then immunized i.m. at day 176 (18 months old) with buffer alone, post-F or pre-F (0.3 μg) +/- GLA-SE (2.5 μg/2%) adjuvant. At day 190, aged seropositive mice were challenged with RSV A2 (10⁶ PFU). 4 days later, lung cells were isolated and stimulated with RSV F peptide pool. Cells were then surface stained for CD3 and CD8, intracellularly stained for IFNγ, TNFα, and IL-2, and analyzed on an LSR II for the frequency of responding (A) CD4+ and (B) CD8+ T cells.