DNA Damage Baseline Predicts Space Radiation and Radio-Therapeutic Resilience

Deep space exploration will require real-time, minimally invasive astronaut health monitoring to mitigate at the individual level the potential health impairments caused by space radiation and microgravity. Genotoxic stress in humans can be monitored by quantifying the amount of DNA double strand breaks (DSB) in immune cells from a simple finger prick. In a cohort of 300+ healthy donors, we first showed that the endogenous level of DSB increases with age and latent cytomegalovirus infection. To map the range of human responses to space radiation, we then studied DSB induction and repair in immune cells exposed to galactic cosmic ray components from 480+ healthy donors, and lymphocytes from 30 cancer patients after radiotherapy. Individuals with low baseline DSB showed less clinical complications, enhanced DNA damage repair response, and a functional dose-dependent cytokine response in healthy donor cells. This supports the use of DSB monitoring for health resilience in space.