Priming of OVA-Tg in vitro with cells from TLI-preconditioned mice enhances differentiation of antigen-specific T_H2 cells.

Purified naive OVA-Tg CD4⁺ cells were cultured with 100 nM OVA peptide and APCs from untreated BALB/c mice (BALB/c), TLI-preconditioned BALB/c mice (TLI), or a 1:1 mixture of BALB/c/TLI for 5 days. OVA-Tg from these primary cultures then were purified and restimulated directly with OVA peptide and fresh APCs from untreated BALB/c mice in cytokine ELISPOT wells as per “Materials and methods.” Bars represent the number of IFN-γ–producing (open) or IL-4–producing (hatched) OVA-Tg cells 72 hours after secondary stimulation from one experiment. The figure depicts a single representative experiment of 3 separate experiments.