Aspects of the HA peptide model system. (A) Positioning of MHC class I and II peptides along the primary sequence of influenza HA antigen. (B) Representation of the class I/II overlapping peptide pair (B8-166/DR3-162), the sequence comparison of which is predicted to be disrupted by ethanolamine. The control class I/II overlapping peptide pair (A2-443/DR3-440) is predicted to be unaffected by the presence of ethanolamine.