Indirect Recruitment of a CD40 Signaling Pathway in Dendritic Cells by B7-DC Cross-Linking Antibody Modulates T Cell Functions
Figure 1
CD40 is rapidly recruited into complexes containing MHC MHC class II on dendritic cells treated with B7-DC XAb.
(A) DCs were pre-stained with APC-labeled antibody against MHC class II and PE-labeled antibody against CD40 for 15 min. An aliquot of cells was analyzed by flow cytometry (0 min time point). The remaining cells were then treated with 10 µg/ml IgM control antibody (filled histograms) or B7-DC XAb (open histograms). Cells were sampled at the indicated time points and analyzed for a FRET (FL3 channel). (B) Lysates were prepared from untreated DC (0′) or DC treated with control antibody or B7-DC XAb for the indicated times and subjected to immunoprecipitation using an antibody against MHC class II. The resultant complexes were resolved by SDS-PAGE, transferred to PVDF membrane, and probed for CD40. IgH serves as a loading control. The results shown are representative of 2 experiments.