Figure 2.

DNA immunization protocols. Constructs were generated as described in Methods (see also reference 25), and plasmid injections were given intramuscularly into the quadriceps femoris muscle on each side (50 μg in 50 μL saline per injection), by 1 of the 3 protocols shown. For each protocol, the paired DNA injections are indicated by arrows; time between each set of injections was 7 days (protocol 1) or 3 days (protocols 2 and 3). The development of IDDM was followed for >3 months after LCMV infection. *Time at which LCMV-specific CTL responses were evaluated.