Peroxiredoxin II regulates effector and secondary memory CD8+ T cell responses

Area of Science:

• Immunology
• Cellular Biology
• Oxidative Stress

Background:

• Reactive oxygen intermediates (ROI) are crucial for cellular responses.
• The role of hydrogen peroxide (H2O2) in antigen-specific CD8(+) T cell responses remains unclear.
• Peroxiredoxin II (PrdxII) is an antioxidant enzyme upregulated upon T cell receptor (TCR) stimulation.

Purpose of the Study:

• To investigate the impact of increased H2O2 on CD8(+) T cell responses.
• To determine the function of PrdxII in regulating CD8(+) T cell proliferation, differentiation, and memory formation.

Main Methods:

• Utilized PrdxII-deficient mice and wild-type controls.
• Employed in vitro cell division assays.
• Adoptive transfer of T cell receptor (TCR) transgenic cells.
• Infection models (acute viral, bacterial, and chronic viral).

Main Results:

• PrdxII deletion elevated ROI, S phase entry, division, and death in vitro.
• PrdxII deficiency increased effector CD8(+) T cells during acute infections but not memory cells.
• T cell-autonomous expansion of effector cells was observed.
• Rechallenge of PrdxII-deficient mice resulted in a larger secondary memory CD8(+) T cell pool.
• Chronic viral infection in PrdxII mutant mice led to accumulation of antigen-specific CD8(+) T cells and mortality.

Conclusions:

• PrdxII is a key regulator of effector CD8(+) T cell expansion.
• PrdxII influences the generation of secondary memory CD8(+) T cells.
• PrdxII plays a critical role in controlling T cell-mediated immunopathology during chronic infections.