Sphingolipid biosynthesis is essential for metabolic rewiring during T_H17 cell differentiation

Area of Science:

• Immunology
• Cellular Metabolism
• Biochemistry

Background:

• T helper 17 (T_H17) cells play a key role in autoimmune diseases.
• Metabolic processes are critical for T_H17 cell differentiation and function.

Purpose of the Study:

• To investigate the role of de novo sphingolipid synthesis in T_H17 cell development.
• To elucidate the molecular mechanisms linking sphingolipid synthesis to T_H17 cell metabolism and function.

Main Methods:

• Studied the effects of SPTLC1 deficiency on T_H17 cell differentiation in vitro and in vivo.
• Assessed glycolysis, reactive oxygen species (ROS) production, and key signaling pathways (mTORC1, HIF-1α, c-Myc).
• Evaluated the impact of SPTLC1 deficiency on experimental autoimmune encephalomyelitis and T cell transfer colitis models.

Main Results:

• SPTLC1 deficiency impaired de novo sphingolipid synthesis, leading to reduced glycolysis in T_H17 cells.
• This impairment was mediated by increased ROS via enhanced NADPH oxidase 2 activity.
• Increased ROS inhibited mTORC1 activation and reduced expression of HIF-1α and c-Myc-induced glycolytic genes.
• SPTLC1 deficiency conferred protection against experimental autoimmune encephalomyelitis and colitis in mice.

Conclusions:

• The de novo sphingolipid biosynthetic pathway is essential for T_H17 cell development and function.
• Targeting this pathway holds therapeutic potential for autoimmune diseases.
• Sphingolipid metabolism critically influences adaptive immune responses.