Glucose-dependent glycosphingolipid biosynthesis fuels CD8⁺ T cell function and tumor control

Area of Science:

• Immunology
• Cell Metabolism
• Biochemistry

Background:

• Glucose is vital for T cell proliferation and function.
• The precise metabolic roles of glucose in vivo are not fully understood.

Purpose of the Study:

• To identify key glucose metabolic pathways essential for CD8+ T cell function in vivo.
• To elucidate the role of glycosphingolipid (GSL) biosynthesis in T cell responses.

Main Methods:

• Utilized 13C-based stable isotope tracing to track glucose metabolism in CD8+ T cells.
• Employed genetic inhibition of key enzymes in GSL biosynthesis (UGP2, GALE, UGCG).
• Assessed CD8+ T cell expansion, cytotoxic function, and tumor control in vivo.

Main Results:

• Identified GSL biosynthesis as a major glucose-dependent pathway in CD8+ effector T cells.
• Demonstrated that inhibiting GSL production impairs T cell expansion and cytotoxic function.
• Showed glucose-dependent GSL synthesis is necessary for plasma membrane lipid raft integrity and T cell receptor (TCR) signaling.

Conclusions:

• Glucose is essential for CD8+ T cell responses through GSL biosynthesis, beyond its role in energy production.
• GSL biosynthesis is critical for maintaining T cell receptor signaling and cytotoxic effector functions.
• Targeting GSL synthesis impacts T cell-mediated immunity and tumor control.