Figure 1. 4°M Lung T_rm Exhibits Increased Durability Relative to 1M Lung T_rm.

(A) Generation of memory CD8⁺ T cells. A sequential P14 adoptive transfer approach and IN infection with PR8-GP33 were used to obtain 1M (blue) and 4M (red) T cell responses that could be analyzed simultaneously.

(B) Groups of mice bearing 1M (blue) and 4°M (red) P14 cells were euthanized at days 30, 50, 100, and 150 p.i. Representative plots of % of CD69 and CD103 expression in IV⁻P14 at the indicated time points (left). Cumulative results depicting numbers of T_rm (IV⁻CD69⁺CD103⁺) in the lung (right). n = 3–4 mice/group. Representative of three independent experiments. Error bars represent mean ± SD. **p = 0.0034, *p = 0.0162, unpaired t test.

(C) Representative plot of lung IV⁻ P14 cells 450 days p.i. Percentages of CD69⁺CD103⁺ T_rm are indicated.