Memory CD8⁺ T cells upregulate glycolysis and effector functions under limiting oxygen conditions

Area of Science:

• Immunology
• Cellular Metabolism
• Oxygen Biology

Background:

• Memory CD8+ T cells are crucial for long-term immunity against pathogens and tumors.
• The role of local oxygen levels on memory CD8+ T cell function in hypoxic environments like infected tissues or tumors is not well understood.

Purpose of the Study:

• To investigate the impact of oxygen pressure on memory CD8+ T cells generated after Listeria monocytogenes-OVA infection.
• To elucidate how altered oxygen levels influence the metabolic and functional characteristics of memory CD8+ T cells.

Main Methods:

• In vitro culture of memory CD8+ T cells under varying oxygen pressures.
• Quantitative proteomic analysis to assess metabolic pathway changes.
• Assessment of T cell expansion, granzyme B, and IFN-γ production.
• In vivo bacterial rechallenge experiments.

Main Results:

• Reduced oxygen pressure induced a metabolic shift from oxidative phosphorylation to glycolysis in CD8+ T cells.
• Low oxygen increased glucose transporter and glycolytic enzyme expression while decreasing mitochondrial proteins.
• Altered metabolism enhanced granzyme B and IFN-γ production without affecting expansion potential.
• In vivo, low oxygen-cultured memory CD8+ T cells conferred protection against bacterial challenge.

Conclusions:

• Oxygen pressure significantly impacts memory CD8+ T cell metabolism and effector functions.
• Reducing oxygen during culture can enhance the functional capacity of memory CD8+ T cells.
• These findings suggest that manipulating oxygen levels during cellular immunotherapy may improve therapeutic outcomes.