Cytokine expression and T-cell polarization on Ag presentation by ABCs. (A) Sorted ABCs and aged or young FO B cells were cultured with stimuli shown for 3 days. RNA was extracted and analyzed for expression of cytokines by qPCR. Fold change is relative to the expression level of each gene in standard total mouse RNA. (B) CFSE-labeled naive OTII CD4⁺ T cells (L-selectin^hiCD44^lo) were cultured with polarizing cytokines and Ab for 5 days, in the presence of young or aged FO or DC (CD11c^hi) that had been pulsed with ovalbumin_323-339 peptide. Intracellular expression of cytokines and CFSE dilution were analyzed on gated CD4⁺ OTII T cells.