Figure 3. Direct TGF-β signaling is required for polyclonal influenza-specific Tfh differentiation.
5 × 106 CD44lo Thy1.2+ CD4 T cells from TGF-βRIIf/f Lck-cre− (WT) or TGF-βRIIf/f Lck-cre+ (KO) mice were adoptively transferred into congenic Thy1.1+ OT-II TCR transgenic mice and infected with WSN-GP33/66 the following day. 14 days p.i., host OT-II (Thy1.1+) and donor (Thy1.2+) CD4 T cells in the MLN (A) and spleen (B) were assessed for expression of CD44 (to distinguish activated T cells, see histogram plots left) and CXCR5, PSGL1, and Ly6C to distinguish Tfh and Th1 attributes. FACS plots are from representative mice and bar graphs are representative of one of four independent experiments (n = 4–5 mice/group/ experiment). *p < 0.05 and colored asterisks correspond to the color in the stacked graphs.