Figure 3.

Enhancement of the splenic HIV-specific CTL response by mucosal (not systemic) treatment with rmIL-12 in mice with preexisting immunity to vaccinia. BALB/c mice (five mice per group) with preexisting immunity to vaccinia were immunized by the s.c. or IR route with recombinant vaccinia virus with or without 1 μg of rmIL-12 and also on day 5,10 and 15 (a). For s.c. immunization, the IL-12 was given i.p., whereas for IR immunization, the IL-12 was given IR in DOTAP with the virus. Boosting of P18–89.6R10-specific CTL responses in the SP of BALB/c mice (b and c). BALB/c mice (5/group) were immunized either s.c. (b) or IR (c) with MVA89.6 vaccinia virus at 5 × 10⁷ pfu. One month later the mice were reimmunized either s.c. or IR with the same recombinant vaccinia MVA89.6 at 1 × 10⁸ pfu. Three weeks later the induction of P18–89.6R10-specific CTL responses were studied in the SP. The percent specific ⁵¹Cr release was calculated as described in Materials and Methods. E:T, effector-to-target ratio.