Figure 1.

Cross-presentation of OVA depends on antigen dose. A total of 5 × 10⁶ Rag-1-deficient OT-I cells were labeled with CFSE and adoptively transferred i.v. into either RIP-OVA^lo mice (Top), RIP-OVA^hi mice (Middle), or RIP-mOVA mice (Bottom). Three days later, the pancreatic (Left) and inguinal (Right) LN cells were analyzed by flow cytometry. As previously reported (7), negative littermates did not induce proliferation of Rag-1-deficient OT-I cells (data not shown). Histograms were gated on CD8⁺CFSE⁺ cells.