Radiation Induces Persistent Dysregulation and Functional Impairment in CD8+ T Cell Immunity

Area of Science:

• Immunology
• Radiation Biology
• Infectious Disease

Background:

• Radiation exposure induces long-term immune system dysfunction, particularly affecting T lymphocytes.
• The persistent consequences and underlying mechanisms of radiation-induced T cell abnormalities in acute radiation syndrome survivors remain unclear.

Purpose of the Study:

• Investigate the delayed effects of acute radiation exposure on CD8+ T cell immunity.
• Elucidate the impact of radiation on CD8+ T cell functionality across different differentiation stages.

Main Methods:

• Utilized a Listeria monocytogenes infection model in mice exposed to sublethal radiation doses.
• Performed single-cell transcriptomic profiling to analyze CD8+ T cell function post-irradiation.
• Conducted differential gene expression analysis to identify radiation-induced molecular changes.

Main Results:

• Mice showed impaired CD8+ T cell activation, reduced terminal effector formation, and exacerbated listeriosis 4 weeks post-irradiation.
• Single-cell profiling revealed altered T cell cluster distribution and impaired effector/memory precursor formation after infection.
• Radiation induced cluster-specific gene expression changes in cytokines and mitochondrial proteins post-infection.

Conclusions:

• Acute radiation exposure leads to delayed dysfunction in CD8+ T cell immunity.
• Newly replenished naive T cells exhibit functional deficits, contributing to overall impaired T cell-mediated protection.
• Radiation-induced molecular alterations in T cells underlie persistent immune deficiencies.