Succinyl-CoA Ligase Deficiency in Pro-inflammatory and Tissue-Invasive T Cells

Area of Science:

• Immunology
• Cell Biology
• Metabolic pathways

Background:

• Autoimmune T cells in rheumatoid arthritis (RA) exhibit defective mitochondrial respiration and ATP synthesis.
• Succinate-CoA ligase GDP-forming subunit (SUCLG2) deficiency is identified as a key metabolic abnormality in RA T cells.

Purpose of the Study:

• To investigate the functional consequences of SUCLG2 deficiency in T cells from RA patients.
• To elucidate the role of altered metabolism and tubulin acetylation in T cell-driven autoimmune inflammation.

Main Methods:

• Analysis of mitochondrial function and metabolic profiles in T cells.
• Assessment of T cell differentiation, migration, and cytokine production.
• Investigation of tubulin acetylation and its impact on cellular phenotype and function.

Main Results:

• SUCLG2 deficiency causes T cells to reverse the tricarboxylic acid (TCA) cycle, accumulating metabolites like acetyl-CoA (AcCoA).
• High AcCoA levels in RA T cells promote tubulin acetylation, stabilizing microtubules and enhancing cell migration and tissue invasion.
• SUCLG2-deficient T cells are hyperinflammatory, producing cytokines and contributing to synovitis; this defect is reversible by enzyme replenishment.

Conclusions:

• Mitochondrial dysfunction and AcCoA oversupply in T cells are linked to autoimmune tissue inflammation in RA.
• Targeting T cell metabolic reprogramming and tubulin acetylation may offer therapeutic strategies for rheumatoid arthritis.