LAT1 enables T cell activation under inflammatory conditions

Area of Science:

• Immunology
• Molecular Biology
• Rheumatology

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint inflammation.
• T cells play a critical role in the pathogenesis of RA.
• Identifying novel therapeutic targets is crucial for managing RA.

Purpose of the Study:

• To investigate the role of L-type amino acid transporter-1 (LAT1) in RA pathogenesis.
• To evaluate LAT1 as a potential therapeutic target for RA.

Main Methods:

• Immunohistochemistry and transcriptomic analysis of synovial tissue from RA patients.
• RNA-sequencing and Total Internal Reflection Fluorescence (TIRF) microscopy in mouse models.
• Assessment of a LAT1 inhibitor in experimental arthritis models.

Main Results:

• LAT1 is upregulated in CD4+ T cells in RA synovium, correlating with disease severity markers (ESR, CRP, DAS-28).
• LAT1 deficiency in murine CD4+ T cells inhibits experimental arthritis development and pathogenic T cell differentiation (IFN-γ, TNF-α).
• LAT1 inhibition with a clinical-stage small molecule effectively ameliorates experimental arthritis in mice.

Conclusions:

• LAT1 is essential for pathogenic T cell activation in inflammatory conditions like RA.
• Targeting LAT1 represents a promising novel therapeutic strategy for rheumatoid arthritis.