T Cell Transcriptome Alterations in Healthy Volunteers Exposed to Three Weeks of Simulated Microgravity

Impairment or reduction of lymphocyte-mediated immune response has been observed during space flight or in microgravity simulation conditions, with the underlying mechanisms remaining unclear. T lymphocytes (T cells) play a critical role in human immune response. The immunosuppression encountered by humans in microgravity may be linked to its impact on T cell global transcriptome networks, affecting immune cell-cell interactions. This study involved a unique three-week microgravity simulation conducted with ten healthy male volunteers aged 25-40 using a dry immersion facility. The research aimed to explore the normal responses of the human body to long-term simulated microgravity (SMG) without any specific countermeasures implemented. To investigate the T cell response to SMG, total RNA isolated from T lymphocytes at different time points during the course of SMG was subjected to RNA sequencing. Bioinformatic analysis revealed the impact of SMG on multiple cell signaling pathways, influenced by key regulators that modulated the expression of different genes. The discovery of potential biomarker genes in T cells may offer valuable insights into studying human responses to microgravity, however, further validation of these findings in space is required.