Fig. 5. Both BCL6 and Bhlhe40 are required for optimal lung T_RH cell responses.

(A to D) Bcl6^fl/fl or Bcl6^ΔT mice were infected with PR8. (A) Representative dot plot, (B) frequencies, and (C) cell numbers of T_RH or non-T_RH in lung CD45_i.v.⁻ total CD4⁺ or CD45_i.v.⁻ influenza-specific CD4⁺ NP_311–325 T cells at 28 d.p.i. (D) Frequencies (top) or cell numbers (bottom) of splenic total T_FH or NP_311–325 T_FH at 28 d.p.i. (E) GSEA of the Bhlhe40-associated genes in lung T_RH (PD-1^HiFR4^Hi) and spleen T_FH cells. (F to H) Bhlhe40^fl/fl or Bhlhe40^ΔT mice were infected with PR8. (F) Representative dot plot, (G) frequencies (top), or cell numbers (bottom) of lung NP_311–325 T_RH or non-T_RH cells at 28 d.p.i. (H) Active caspase 3/7–fluorochrome-labeled inhibitors of caspases (FLICA)⁺ cells in lung NP_311–325 T_RH or non-T_RH cells at 28 d.p.i. In (A) to (D) and (F) to (G), data were pooled from two independent experiments (three to four mice per group). In (H), representative data were from at least two independent experiments (four mice per group). P values were calculated by unpaired two-tailed Student’s t test. Data are means ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.