HLA-Shuttle: A system for enhancing antigen presentation in immunologically cold tumors

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• Cellular immune surveillance relies on T cells recognizing epitopic peptides presented by human leukocyte antigen class I (HLA-I) molecules.
• Reduced surface HLA-I expression is a common immune evasion strategy in latent viral infections and cancer, hindering antigen and neoantigen identification.
• This immune evasion mechanism presents a significant challenge for developing effective immunotherapies.

Purpose of the Study:

• To develop a novel system, termed HLA-Shuttle, for in vitro manipulation of cellular machinery.
• To restore and enhance HLA-I antigen presentation in cells with aberrant HLA-I expression.
• To identify tumor-associated antigens with therapeutic potential in immunologically challenging cancer types.

Main Methods:

• Engineering components of the HLA-I processing machinery to provide continuous chaperoning activity.
• Utilizing HLA-Shuttle for in vitro manipulation of cells, including neuroblastoma.
• Employing cellular trafficking assays and single-particle tracking to analyze HLA-I dynamics.

Main Results:

• HLA-Shuttle successfully restored antigen presentation in immunologically cold neuroblastoma cells.
• Multiple tumor-associated antigens with therapeutic potential were identified.
• Observed global stabilization of HLA-I molecules, extended cell-surface lifetime, and enhanced microdomain formation.
• Demonstrated the system's efficacy across various aberrant cellular states with low antigen expression.

Conclusions:

• HLA-Shuttle offers a versatile platform for overcoming antigen presentation defects in diverse cellular states.
• The system facilitates the identification of endogenous peptide antigens and neoantigens, crucial for cancer immunotherapy.
• This approach holds significant promise for advancing cancer diagnostics and therapeutic strategies by improving immune surveillance.