Priming of OVA-Tg in vitro with cells from TLI-preconditioned mice expands IL-4–producing OVA-Tg CD4⁺cells.

Purified naive OVA-Tg CD4⁺ cells were cultured for 5 days with 100 nM OVA peptide and APCs from either untreated BALB/c mice (A-B) or TLI-preconditioned BALB/c mice (C-D). Cells from these cultures were then restimulated with PMA/ionomycin as per “Materials and methods” and subsequently stained for CD4⁺ and Tg surface markers. The panels depict contour plots of gated OVA-Tg CD4⁺ T cells after PMA/ionomycin restimulation and show intracytoplasmic staining with rat IgG1 isotype control antibodies (A,C) or antibodies against IL-4 and IFN-γ (B,D).