Differential regulation of CD83, CD40, and CTLA-4 is dependent upon the double-loading of DCs with matched class I and II antigens. (A) Percent difference of CD83 expression from average of unloaded and singly loaded controls between matched doubly loaded () and unmatched doubly loaded (□) DCs (P = .009). y-axis equals percent difference from average of unloaded and singly loaded controls. Compilation of 6 independent experiments. (B) Same as panel A but with CD40 staining rather than CD83 (P < .01). Compilation of 4 independent experiments. (C,D) Histograms demonstrating representative results for A (CD83) and B (CD40). (E) Semiquantitative RT-PCR demonstrates differential expression of CTLA-4 between DCs doubly loaded with matched antigens and DCs doubly loaded with mismatched antigens. Matched equals DC loaded with matched class I and II antigens. Mismatched equals DC loaded with mismatched class I and II antigens. +/−, +/− reverse transcriptase.