NEDDylation Regulates CD8+ T-cell Metabolism and Antitumor Immunity

Area of Science:

• Immunology
• Molecular Biology
• Cancer Research

Background:

• NEDDylation, a post-translational modification, involves attaching NEDD8 to protein substrates via NAE1.
• Its role in antitumor immunity, particularly in CD8+ T cells, remains largely uncharacterized.
• Emerging evidence suggests NEDDylation influences cancer biology.

Purpose of the Study:

• To investigate the impact of NEDDylation on CD8+ T cell-mediated antitumor responses.
• To elucidate the mechanisms by which NEDDylation affects T cell function and metabolism.

Main Methods:

• Analysis of single-cell RNA sequencing data of tumor-infiltrating lymphocytes (TILs).
• In vitro activation and genetic manipulation (NAE1 knockout, SENP8 knockout) of mouse and human CD8+ T cells.
• In vivo tumor challenge assays.
• LC-MS/MS proteomic analysis.
• Assays for metabolic pathways (glycolysis, oxidative phosphorylation) and enzyme activity.

Main Results:

• CD8+ TILs showed increased NEDD8 expression during differentiation into effector memory cells.
• NAE1-deficient CD8+ T cells exhibited reduced antitumor capability and impaired effector cell differentiation.
• Upregulating NEDDylation enhanced CD8+ CAR T cell cytotoxicity.
• NEDDylation deficiency impaired metabolic pathways, including glycolysis and oxidative phosphorylation, with reduced lactate dehydrogenase activity.
• Lactate dehydrogenase A, α-enolase, and hexokinase 1 were identified as NEDD8 targets.

Conclusions:

• NEDDylation is a critical regulator of CD8+ T cell-mediated antitumor immunity.
• The modification impacts T cell activation, differentiation, and metabolic fitness.
• Targeting NEDDylation pathways may offer novel strategies for cancer immunotherapy.