Fig. 3.

Clodronate depletion of splenic Mϕ and PTx treatment inhibit Ag presentation by DCs and CTL activation after targeting to MMM. Splenic Mϕ were depleted from the spleen by i.v. injection of 200 μL clodronate liposomes. At day 7, spleens were analyzed for depletion of MMM. MMM were stained for Siglec-1 with SER4 (green) and DCs with αCD11c (red). (A) Original magnifications: ×20. (B) Seven days after clodronate liposome treatment, mice were immunized with indicated mAb-OVA complexes. Sixteen hours after immunization, DCs were purified and used as stimulators of naive OT-I T cells in an ex vivo Ag-presentation assay [starting at 3 × 10⁵ DCs/well (black bars) with 3-fold dilutions (gray and white bars)]. (C) Seven days after Cl₂MBP liposome treatment, animals were immunized with 2.5 μg of indicated mAb-OVA and, after 7 days, in vivo killing of OVA-loaded CFSE-labeled cells was analyzed by FACS. (D) Mice were injected i.p. with 500 ng PTx 8 h before immunization with 2.5 μg mAb-OVA together with 25 μg αCD40. Sixteen hours after immunization, DCs were isolated and tested for their capacity to activate naive OT-I T cells in vivo. Different bars indicate titration of DCs in the assay [starting at 1 × 10⁵ DCs/well (black bars) with 3-fold dilutions (gray and white bars)]. Error bars indicate SEM of triplicate wells. Data are of experiments with three mice per group. ***P < 0.01 versus control animals calculated by t test.