Scaffolds with stabilized mhc molecules for immune-cell manipulation

An artificial antigen presenting cell (aAPC) scaffold comprising a polymeric backbone to which are attached the following template molecules:

• i. at least two different gamma-chain receptor cytokines selected from the group consisting of IL-21, IL-2, IL-15, IL-4, IL-7 and IL-9, wherein the cytokines comprise at least IL-21, and
• ii. at least one MHC class I molecule,
• wherein the MHC class I molecule comprises a heavy chain comprising an alpha-1 domain and an alpha-2 domain connected by a disulfide bridge, and wherein the MHC class I molecule is HLA-A, HLA-B or HLA-C having a mutant cysteine residue positioned in the alpha-1 domain and a mutant cysteine residue positioned in the alpha-2 domain, and wherein the mutant cysteine residue in the alpha-1 domain is at amino acid residue 84 or 85 and the mutant cysteine residue positioned in the alpha-2 domain is at amino acid residue 139, relative to SEQ ID NO:
• 1.