FIGURE 2. IL-12 promotes long duration interactions with DC.
A, OT-1 were primed by Listeria-infected, OVA-pulsed DC for 48 hours in vitro with control or anti-p40 neutralizing antibodies. The duration of interaction between T cells and DC were determined via time lapse video microscopy. B, OT-1 were primed by wild-type, p35−/−, or p40−/− DC as described above and the duration of interaction between T cells and DC were determined via time lapse video microscopy. Dissociation curves are combined data from at least three independent experiments per condition. The solid line in A and B represents 50% of the interactions analyzed. Significance compared to the WT DC + OVA control samples was determined by Cox Proportional Hazard Regression Analysis. The neutralization of IL-12/23 (anti-p40) resulted in a significant decrease in the duration of interaction of OT-1 (p < 0.01) with DC, which was further reduced in the absence of IL-12 (p35−/− DC; p < 0.001) or IL-12/23 (p40−/− DC; p < 0.001).