Fig. 1
From: Novel insights into the HLA class I immunopeptidome and T-cell immunosurveillance
Spliced peptides presented in HLA class I molecules are mainly formed in two ways. After appropriate cleavage by the catalytic subunits of the proteasome the two splice reactants derived from one parental peptide (cis-splicing) can be ligated either in the normal order (top variant) or in the inverted reverse order of the parental amino acid sequence (bottom variant). The intervening sequence is removed, giving rise to a novel antigenic sequence if the novel peptide has appropriate HLA class I binding capacity