Daniel Hwang, Molly C. Erdman, Santosh Adhikari, Ram Pantula, Kaya Epstein, Peiyao Li, Francesca Costabile, Photis Rotsides, Chloe S. Wang, Shirley M. Sun, Hossein Fazelinia, Lynn A. Spruce, Tim Fugmann, Trëndelina Rrustemi, Wai Tuck Soh, Alvin Farrel, Muzamil Y. Want, Andrea Facciabene, Mustafa Mir, J. M. Maris, Nikolaos G. Sgourakis
Epitopic peptides presented by class-I human leukocyte antigen (HLA-I) proteins provide the basis of immune surveillance by T cells. Conversely, reduced surface HLA-I expression is a hallmark of immune evasion by latent viral infections and cancer, which confounds the identification of peptide antigens and neoantigens. Here, we outline a system (HLA-Shuttle) for in vitro manipulation of cells with engineered components of the HLA-I processing machinery to confer a continuum of chaperoning activity throughout their trafficking pathway. HLA-Shuttle restores antigen presentation in immunologically cold neuroblastoma cells, enabling identification of multiple tumor-associated antigens with therapeutic potential. Cellular trafficking assays and single-particle tracking reveal a global stabilization of HLA-I molecules, extension of their cell-surface lifetime and microdomain formation. HLA-Shuttle can be used across a range of aberrant cellular states where low antigen expression remains a bottleneck for the identification of endogenous peptide antigens.