Relative abundance of ADAMTS13 CUB2–derived peptides in ADAMTS13 and PBS-treated DCs. DCs isolated from donor 10 were treated with 500 nM of ADAMTS13 or PBS. The MHC II–eluted peptides isolated from the cells were analyzed by mass spectrometry. SIEVE was used to compare intensities of individual peptides eluted from MHC II isolated from ADAMTS13- or PBS-treated DCs. (A) Total ion current chromatogram of ADAMTS13- and PBS-treated cells. (B-C) Reconstructed ion chromatogram of 2 identified ADAMTS13 peptides are shown for both ADAMTS13 and PBS samples. Red and blue chromatograms represent peptides obtained from ADAMTS13 and PBS samples, respectively.