The glucose transporter Glut1 is selectively essential for CD4 T cell activation and effector function

Area of Science:

• Immunology
• Cell Metabolism

Background:

• CD4 T cell activation results in effector (Teff) and regulatory (Treg) cell differentiation, with distinct metabolic preferences in vitro.
• In vivo requirements for glucose uptake and metabolism in T cells remain unclear.
• Multiple glucose transporters exist, but their specific roles in T cell subsets in vivo are not well-defined.

Purpose of the Study:

• To investigate the in vivo role of glucose transporter 1 (Glut1) in CD4 T cell metabolism and function.
• To determine the impact of Glut1 deficiency on Teff and Treg cell activation, expansion, and survival in vivo.

Main Methods:

• Utilized mouse models with selective Glut1 deficiency.
• Analyzed T cell activation, glucose uptake, glycolysis, proliferation, and differentiation.
• Assessed in vivo Teff expansion and inflammatory disease induction.
• Evaluated Treg cell function and suppressive capacity.

Main Results:

• Glut1 deficiency selectively impaired thymocyte and Teff cell metabolism and function upon activation.
• Lack of Glut1 prevented increased glucose uptake, glycolysis, growth, and proliferation in activated T cells.
• Glut1 deficiency reduced Teff cell expansion and in vivo inflammatory disease induction.
• Treg cells were enriched and functionally intact in Glut1-deficient settings, maintaining suppressive capacity.

Conclusions:

• Glut1 is essential for the metabolic reprogramming required for CD4 T cell activation, Teff expansion, and survival in vivo.
• Glut1 is not required for Treg cell function, which can expand and suppress Teff cells independently.
• Targeting Glut1 may offer a strategy to modulate T cell-mediated immunity.