Figure 2.

DCs process and present antigen delivered by hybrid antibodies. (A) MHC II and CD80 expression on DCs is not altered by multiple injections of αDEC/HEL and 3A9 T cells. B10.BR mice transferred with 3A9 T cells and controls were injected subcutaneously in the footpads with 0.2 μg αDEC/HEL or PBS either at 8 d (αDEC/HEL) or at 1 and 8 d (αDEC/HELX2) after transfer (similar results were obtained by intravenous injection of chimeric antibodies, data not shown). 24 h after the last αDEC/HEL injection, DCs were purified from peripheral LNs and analyzed by flow cytometry for expression of CD80 and MHC II. Dotted lines in histograms indicate PBS control. (B) αDEC/HEL delivers HEL peptide to DCs in vivo. B10.BR mice were injected subcutaneously into footpads with 0.3 μg of αDEC/HEL or GL117/HEL or αDEC or PBS as indicated. CD11c⁺, CD19⁺, and CD11c⁻CD19⁻ cells were isolated from draining LNs 24 h after antibody injection and assayed for antigen processing and presentation to purified 3A9 T cells in vitro. T cell proliferation was measured by [³H]thymidine incorporation and is expressed as a proliferation index relative to PBS controls. The results are means of triplicate cultures from one of four similar experiments.