Socioenvironmental stressors encountered during spaceflight partially affect the murine TCR-β repertoire and increase its self-reactivity

Spaceflightsare known to affect the immune system. In a previous study, we demonstrated that hypergravityexposure during murine development modified 85% of the T-cell receptor(TCR)-β repertoire. In this study, we investigated whether socioenvironmental stressors encountered during space missions affect T lymphopoiesisand the TCR-β repertoire. To address this question, pregnant mice were subjected throughout gestation to chronic unpredictable mild stressors (CUMS), a model used to mimic socioenvironmental stresses encountered during space missions. Then, newborn T lymphopoiesisand the TCR-β repertoirewere studied by flow cytometry and high-throughput sequencing, respectively. No change in thymocyte maturation or TCR expression were noted. TCR-β repertoireanalysis revealed that 75% of neonate TCR-β sequences resulted from the expression of 3 variable (V)β segments and that this core repertoirewas not affected by CUMS. However, the minor repertoire, representing 25% of the global repertoire, was sens...