Scientists of Stanford University and University of California in San Francisco proved that cosmic flights significantly weaken the immune system of astronauts due to the anomalous activation of regulatory T cells (Tregs). Details about the dangers of long-staying in space are disclosed in an article published in the Journal Scientific Reports.
In the course of the study, experts were allocated 18 types of immune cells in blood samples and traced in 252 specific reactions in microgravity conditions. To do this, they applied a cytometry method, which includes the lake with stable isotopes of rare earth metals and mass spectrometry, in which the substance is identified by the mass ratio and charge of the ions obtained from its molecules. Cytometry allows you to determine and quantify dozens of proteins involved in an immune response.
To simulate the impact of weightlessness, scientists have used a centrifuge for four hours. Particular attention was paid to 14 functional responses, including phosphorylation of molecules involved in the main signaling paths, as well as the activity of special biomarkers activation of immune cells.
Tregs is usually started to suppress the immune response after infection and plays an important role in various diseases, including cancer or COVID-19. However, the authors of the work found out that in the conditions of microgravity, regulatory T cells begin to work before the immune system is activated. When experts stimulated the immune response in blood samples using a chemical signal that simulates the impact of the pathogen, Tregs suppressed a protective reaction.
Previously, scientists have found that microbrivation also weakens the activation of T-lymphocytes and makes less effective T-killers – immune cells that destroy damaged or infected organism cells. In general, researchers hope that the results of the work will help develop methods for mitigating consequences for the human body during long-term space travel.