The endogenous regulation of the cytokine disbalance in humans subjected to simulated spaceflight environment

: Confinement is one of the stress-inducing factors which humans face in such terrestrial environments as those in polar winter-over expeditions, submarines, and is inevitable in space flights. Confinement regime (CR) itself includes a number of stress factors (e.g. psychological compatibility between crew members, microbiological contamination etc.), which have been shown to alter human immunity. Two groups of total seven subjects spent 110 days in closed-habitat chamber as part of SFINCSS (Stimulation of Flight of International Crew on Space Station) study. Distribution of T-cell subsets, NK-, B-cells, and monocytes in whole blood was assessed. Secretion of type I (IL-2, IFN-gamma, TNF-beta) and type II (IL-4, IL-10) cytokines in the LPS/PHA activated whole blood cell culture was assessed. Significant alterations in type I / type II cytokine equilibrium were observed during and after confinement. The data show that stress factors associated with confinement may lead to disbalance between cell-mediated and humoral immune reactions.