Immunization of mice with gene gun–transfected mature DCs with pCMV-OVA 489 or infected with rAd-CMV-OVA-489 induces OVA-specific CTL response. Induction of OVA-specific CTL response in mice immunized with mature DCs transfected with pCMV-OVA-489 or infected with rAd CMV-OVA-489 and signaled through CD40. Comparisons of CTL response induced by mature DCs transfected with lipofectamine, electroporation, Ca₂PO₄ precipitation, and gene gun or infected with rAd are displayed. Gene gun and rAd induced the highest CTL response compared with other naked DNA transfection methods (P < .001). There were no significant differences between CTL responses induced by mature DCs transfected with gene gun or infected with rAd (P > .05). Immunizations with mature DCs transfected with gene gun or infected with rAd induced a higher CTL response than immunizations performed with mature DCs pulsed with SIINFEKL peptide (P < .05). Mature DCs transfected with other DNA methods induced CTL levels similar to negative controls. Negative controls included mature DCs signaled with CD40 and gene gun transfected with pCMV-LacZ or rAd CMV-LacZ, and naive mice injected with PBS. Means ± 1 SE from triplicates are shown. Results from 1 of 3 representative experiments are displayed.