Fig. 5 In vivo induction of epitope-specific CTLs in vivo. HLA-A*0201/Kb mice were immunized with 100 μg of various peptides prepared in incomplete Freund’s adjuvant (IFA) and boosted once a week for three times. As a control, mice were injected with an IFA emulsion without peptide. 7 days after immunization, splenocytes from injected animals were cultured and used as effector cells. The cytotoxic activities of CTLs were determined against target cells at various E/T ratios using 51Cr release assay. Experiments performed in triplicate showed consistent results. Compared with controls, P < 0.05