Extreme environment provides clues about socio-environmental stressors contribution to ISS-induced changes in antibody repertoire.

Spaceflight-induced immune system dysregulation coupled with limited clinical care represents a risk for crew members. This study aimed to discern which stressor encountered during a space mission impact the antibody repertoire. Via next-generation sequencing, we analyzed the immunoglobulin heavy chain repertoire of volunteers wintering for a year in Antarctica at two stations, Neumayer III (sea level) and Concordia (altitude of 3233 m), which are recognized ground-based analogs of the space environment except for the gravity change and radiation. Our results showed that, as in space crewmembers, 40% of individuals at both stations developed significant changes in their antibody repertoire during polar night. Furthermore, similar to cosmonauts, these modifications were associated with a modification of the V(D)J recombination process responsible for creating antibody genes. These results suggest that physical and socioenvironmental stressors alone can contribute to antibody repertoire changes, confirming the need to implement operational improvements and personalized approaches during future deep-space exploration missions.