Fig. 2.

Activation of the AHR during development increases the frequency of T helper type 1 (Th1) cells and regulatory CD4⁺ T cells (Tregs) in the infected lung. Mice were developmentally exposed and infected with influenza virus at maturity. Cell suspensions of lung-derived immune cells were prepared and stained for flow cytometry. CD4⁺ T-cell subsets are defined as follows: Th1 cells: TBet⁺CD4⁺; Th17 cells: RORγt⁺CD4⁺; and Tregs: Foxp3⁺CD25⁺CD4⁺. Representative dot plots depict the percentage of Th1 cells (A), Th17 cells (C), and Tregs (E). The bar graph shows the number of Th1 cells (B), Th17 cells (D), and Tregs (F). Values are means ± SE; n = 5–6 offspring per treatment from separately treated dams. *P value ≤ 0.05. SSC-A, side scatter area; TBet, T-box transcription factor TBX21; RORγt, retinoid-related orphan receptor-γt; Foxp3, forkhead box protein P3.