Figure 1.

PPAR-γ (Lyz2-Cre cKO) mice exhibit enhanced flu-specific T_RM response. Wt C57BL/6 and PPAR-γ^fl/fl x Lyz2-Cre mice were infected with PR8 influenza virus. (A) Percentage of initial body weight was monitored from day 0 to 19. (B) CD8 T cells were assayed by flow cytometry day 60 post-infection. From lung digests and spleens following intravenous injection of CD45 Ab (CD45 i.v.) to label circulating white blood cells. The lung-resident (CD45 i.v.–, filled), lung circulating (CD45 i.v.+, open) and splenic (dotted) CD8 T cell compartments were assessed for CD69 expression (top panel). Dot plots of CD69 and CD45 i.v. staining in whole lung CD8 T cells (second panel) and D^b-NP and PA specific CD8 T cells in each of the lung compartments (bottom two panels). (C) Frequencies (left) or numbers (right) of influenza-specific D^b-NP and D^b-PA tetramer⁺ cells were quantitated by flow cytometry. Resident memory T cells were defined as (CD8α⁺ CD69⁺ tetramer ⁺ CD45⁻ i.v.–) and circulating (Circ) memory T cells were defined as (CD8α⁺ tetramer⁺ CD45⁺ i.v). (D) Numbers of influenza-specific D^b-NP (top) and D^b-PA tetramer⁺ cells (bottom) in the spleens were measured by flow cytometry. Central (T_CM) and effector (T_EM) memory T cells from the spleen were defined as CD8α⁺ CD44^Hi CD127⁺tetramer⁺ and were, respectively, CD62L^Hi/Lo. (E–G) Lung and blood effector T cells were quantified at 10 days post infection. (E) Representative FACS-plot of Db-NP or Db-PA tetramer staining in CD8 T cells of the whole lung or blood. (F) Frequencies (upper panel) and numbers (lower panel) of influenza-specific D^b-NP and D^b-PA tetramer⁺ CD8 T cells in lungs. (G) Frequencies of D^b-NP and D^b-PA tetramer⁺ CD8 T cells in blood. ^*p < 0.05 for cKO compared to wt. Data are representative of three experimental replicates, except (D,G).