Mitochondrial fission induces immunoescape in solid tumors through decreasing MHC-I surface expression

Area of Science:

• Immunology
• Cancer Biology
• Mitochondrial Biology

Background:

• Mitochondrial dynamics influence cancer cell immunogenicity and Major Histocompatibility Complex (MHC)-I expression.
• The IRE1α-XBP-1s pathway is critical in linking mitochondrial fragmentation to cancer immunogenicity.
• XBP-1s, a transcription factor, regulates TPP2, which may degrade tumor antigen peptides, thus inhibiting MHC-I surface expression.

Purpose of the Study:

• To investigate the role of mitochondrial dynamics in regulating cancer cell immunogenicity.
• To explore the potential of targeting mitochondrial fission for enhancing cancer immunotherapy.

Main Methods:

• Utilized Mdivi-1, a mitochondrial fission inhibitor.
• Assessed Major Histocompatibility Complex (MHC)-I expression on cancer cells.
• Evaluated the efficacy of adoptive T cell therapy in patient-derived tumor models.

Main Results:

• Mitochondrial fission inhibition using Mdivi-1 upregulated MHC-I expression on cancer cells.
• Inhibition of mitochondrial fission enhanced the effectiveness of adoptive T cell therapy in patient-derived tumor models.
• The IRE1α-XBP-1s axis plays a key role in the observed effects.

Conclusions:

• Mitochondrial fission inhibition represents a potential strategy to augment cancer cell immunogenicity.
• Targeting mitochondrial dynamics, specifically fission, may improve the efficacy of T cell-based immunotherapies for cancer treatment.