Impact du stress sur la survie des lymphocytes T CD8+ mémoires dans le contexte des missions spatiales
The immune memory allows the body to remember all pathogens encountered in order to mount a faster and more effective immune response upon reinfection. After the contraction phase of the primary response, memory CD8 T cells survive in the presence of cytokines such as interleukin 15 (IL-15). These cells also allow the immune system to control latent viruses that were not completely removed from the host. Situations of chronic stress affect the immune system, causing the reactivation of these latent viruses. High viral titers of Herpesviridea family viruses were observed in astronauts upon their return, suggesting that hormones released under stress have a negative impact on memory CD8+ lymphocytes. An in vitro murine model of chronic stress has been developed by adding corticosterone to CD8+ memory T cells. It has been shown that the stress hormone had a pro-apoptotic effect on these cells and that this effect was partially inhibited by the addition of IL-15. Molecular targets have also been identified to monitor the memory immune function during spaceflight using the Microflow-1 cytometer, a new portable platform for biomedical diagnosis. The results of laboratory tests and the International Space Station (ISS) showed that it is possible to monitor the memory immune function and stress markers in real time during spaceflight.
Stress Vol spatial CD8+ memory T cells Flow cytometry Spaceflight