PROTEIN TRANSFER OF PREFORMED MHC-PEPTIDE COMPLEXES SENSITIZES TARGET-CELLS TO T-CELL CYTOLYSIS

Recombinant GPI-anchored HLA-A2.1 (HLA-A2.1-GPI/beta(2)m) was used as a protein transfer vehicle to deliver a hepatitis B virus antigenic peptide to the surfaces of cytotoxic T cell targets. Empty HLA-A2.1-GPI/beta(2)m was first produced in D. melanogaster cotransfectants and immunoaffinity purified. Cell coating with HLA-2.1-GPI/beta(2)m was shown to occur rapidly, and to be protein concentration dependent. Protein-transferred HLA-A2.1-GPI/beta(2)m effectively presented a hepatitis B virus peptide to peptide-specific HLA-A2.1-restricted T cell crones in cytotoxicity assays. Protein transfer of functional GPI-modified class I MHC-antigenic peptide complexes represents a never strategy for delivering functional antigenic complexes to cell surfaces that bypasses limitations of gene transfer and permits control of antigenic peptide densities at cell surfaces.