11c.OVA BM establishes a long-term tolerogenic environment in primed recipients. (A) Experimental plan. (B-D) B6.SJL (CD45.1+) recipients were immunized (OVA/QuilA), 2 weeks later irradiated (300 cGy) and BM (107) from C57Bl/6; non-Tg, 11c.OVA, MII.OVA, or actin.OVA (act.OVA) mice injected intravenously. Six weeks later CD45.1+CD45.2+ OT-I LN cells (5 × 106) were transferred intravenously. Four weeks later mice were sham (PBS/QuilA) or OVA (OVA/QuilA) challenged. One week after challenge the number of OT-I T cells (CD45.1+CD45.2+CD8+) were enumerated in peripheral blood (B) and the number of IFN-γ producing OT-I T cells in spleen (C) was determined by flow cytometry. Donor chimerism was determined in peripheral blood 1 week after challenge (D). Data represent individual mice pooled from a minimum of 2 experiments. Bars show mean ± SD.