Immunization with AdMDC-modified DCs pulsed with P. aeruginosa protects mice against lethal P. aeruginosa infection by Th2-dominant immunity. The experiments were carried out in a fashion identical to that in Figures 5 and 6 unless otherwise noted. All respiratory challenges were with P. aeruginosa PAO1 3 weeks after the immunization (c–e) or 1 week after the transfer of splenocytes (a and b). Survival was recorded as the percentage of surviving animals (n = 10 mice per group). (a) Adoptive transfer of spleen cells. Splenocytes from C57BL/6 mice immunized as described in Figure 5 were collected 2 weeks after immunization and transferred intravenously to nonimmunized recipients. (b) CD4⁺ or CD8⁺ splenocyte transfer. Two weeks after the immunization, splenocytes were collected from C57BL/6 mice immunized with AdMDC-modified DCs pulsed with P. aeruginosa. After separation into CD4⁺ or CD8⁺ cells using magnetic beads, each cell fraction (5 × 10⁶ CD4⁺ or CD8⁺ cells) or 5 × 10⁷ total splenocytes were transferred intravenously to nonimmunized recipients. (c) Role of CD4⁺ T cells, CD8⁺ T cells, and B cells. CD4⁺ T cell–deficient, CD8⁺ T cell–deficient, B cell–deficient, or wild-type C57BL/6 mice were immunized with AdMDC-modified DCs pulsed with Pseudomonas. (d) MHC class II presentation of DCs. Wild-type C57BL/6 mice were immunized with AdMDC-modified DCs pulsed with Pseudomonas using DCs prepared from MHC class I–deficient, class II–deficient, or wild-type C57BL/6 mice. (e) Th2-dominant response of immunization. IL-4-deficient, IL-12-deficient, or wild-type C57BL/6 mice were immunized with AdMDC-modified DCs pulsed with Pseudomonas.