LC MALDI-TOF MS/MS and LC ESI FTMS analyses of HLA-B27 associated peptides isolated from peripheral blood cells.

Peptides eluted from peripheral blood cells of HLA-B*2705 healthy donor were analyzed by LC MALDI MS/MS and LC ESI FTMS techniques. The sequences of 92 peptide ligands identified from one healthy blood donor by LC MALDI-TOF MS/MS were compared with those previously published from in vitro long-term cell cultures available in SYFPEITHI database and splenocytes. It was found that 18 sequences confirmed within 1ppm mass error by LC ESI FTMS were already described and 3 of them matched with those previously reported from HLA-B*2705 splenocytes. Another 38 sequences validated within the same mass error were not found in SYFPEITHI database and are identified here for the first time. Finally, 36 sequences (5 sequences already published in SYFPEITHI database) were evaluated by LC MALDI-TOF MS/MS but no matches in the list of monoisotopic masses obtained from LC ESI FTMS were found.