Figure 5. Modulation of T cell tuning by commensal flora broadly affects self-reactive CD4⁺ Th1 and Th17 subsets.

(A) Representative expression profiles at day 28 and (B) Frequencies of IFN-γ⁺ and IL17A⁺cells in live, CD4⁺Vβ3⁺ T cells isolated from mLN of mPCC, Cd3e^−/− hosts at the indicated time points post naïve 5C.C7 T cell transfer and restimulated for 3h with PMA and ionomycin or 3μM MCC peptide. (C) Tuning ratios, as described in experimental procedures, for IFN-γ and IL17A in live, CD4⁺Vβ3⁺ T cells isolated from mLN of indicated hosts 14 days post T cell transfer and restimulated for 3h with PMA and ionomycin or 3μM MCC peptide. Data (mean±SEM) pooled from 3 independent experiments (n=6–7 mice per group).

(D–E) 17 or 26 days post T cell transfer, MPF-housed mPCC, Cd3e^−/− hosts were injected with EdU and sacrificed 1hr later. (D) Representative EdU and IFN-γ expression profiles in live, CD4⁺Vβ3⁺ T cells isolated from mLN at day 17. (E) Tuning ratio for IFN-γ in live, EdU⁺ versus EdU⁻ CD4⁺Vβ3⁺ T cells. Data (mean±SEM) pooled from 2 independent experiments (n=3 mice per group).