Patent ID: 8916340

Claim:
A method for producing an isolated or purified complex of an MHC class II restricted peptide from a polypeptide of interest, comprising: (a) optionally, denaturing the polypeptide of interest to produce a denatured polypeptide; (b) incubating the polypeptide or optionally denatured polypeptide in the presence of (i) a soluble human MHC class II protein or an active homologue thereof from another mammalian species; and (ii) soluble human HLA-DM protein or an active homologue thereof from another mammalian species; such that the polypeptide or optionally denatured polypeptide binds to the peptide binding groove of the MHC class II protein, forming a complex with said class II protein; (c) proteolytically digesting exposed regions of said polypeptide or optionally denatured polypeptide so that a peptide of about 10 to about 26 amino acid residues remains bound to the peptide binding groove of said MHC class II protein, thereby producing said complex; and (d) further isolating or purifying said complex, thereby producing said isolated or purified complex of said MHC class II restricted peptide from said polypeptide of interest.