Identification of γ-globin-derived peptides on the cell surface of aAPC/γ-globin. (A) Cell-surface peptides from aAPC/γ-globin were acid stripped and separated by reverse-phase HPLC as described in “Materials and methods.” Peptide fractions were collected, subjected to mass spectral analysis, and fractions corresponding to those of synthetic g031 and g105 peptides were identified. (B) The fraction corresponding to the g105 peptide was subjected to sequencing.