Immunological Aspects of Isolation and Confinement

Abstract

Beyond all doubts, the exploration of outer space is a strategically important and priority sector of the national economy, scientific and technological development of every and particular country, and of all human civilization in general. A number of stress factors, including a prolonged confinement in a limited hermetically sealed space, influence the human body in space on board the spaceship and during the orbital flight. All these factors predominantly negatively affect various functional systems of the organism, in particular, the astronaut’s immunity. These ground-based experiments allow to elucidate the effect of confinement in a limited space on both the activation of the immunity and the changes of the immune status in dynamics. Also, due to simulation of one or another emergency situation, such an approach allows the estimation of the influence of an additional psychological stress on the immunity, particularly, in the context of the reserve capacity of the immune system. A sealed chamber seems a convenient site for working out the additional techniques for crew members selection, as well as the countermeasures for negative changes in the astronauts’ immune status. In this review we attempted to collect information describing changes in human immunity during isolation experiments with different conditions including short- and long-term experiments in hermetically closed chambers with artificial environment and during Antarctic winter-over.

Influence of the spaceflight environment on macrophage lineages

“…Operational on-board stressors that fall into this category include circadian misalignment, social isolation, and closed/hostile environments, all of which may impact macrophage biology. Spaceflight and ground analogs indicate that ICE may disrupt circadian rhythms critical to immune functions (reviewed in 79 , 80 ). More specifically, ICE may impact circadian misalignment by manifesting disruptions in monocyte and macrophage molecular clocks (reviewed in 81 ).…”

Social Isolation: A Narrative Review on the Dangerous Liaison between the Autonomic Nervous System and Inflammation

“…Furthermore, severe impairments of immunological function were associated with latent viral reactivation [ 81 ]. The altered distribution of peripheral leukocytes, the diminished function of specific leukocyte subpopulations and skewed cytokine profiles have also been described in many astronauts [ 20 , 22 , 85 ]. Interestingly, an increase in IL-8 and TNFa levels were associated with a low-grade inflammatory status during spaceflight [ 22 , 86 ], similar to those experienced in old persons [ 87 ].…”

“…When an acute stress occurs, the physiological response is short-lasting and ceases immediately upon removal of the stressor. In the case of chronic stress or persistent stressful events, the prolonged recruitment of the same response to acute stress can result in immune dysregulation or suppression, as shown by data from spaceflights and space analogs [ 22 , 85 ].…”

Understanding the Complexities and Changes of the Astronaut Microbiome for Successful Long-Duration Space Missions

“…Of interest, altered BGMA and microbiome have also been found in conjunction with disrupted sleep physiology, with microbiome diversity being positively correlated with increased sleep efficiency and total sleep time [200]. Cognitive or behavioral conditions reported during spaceflight include reduced sleep quality and increased anxiety and depression, which can be accompanied by the impairment of psychomotor functions and neurocognitive performance [210,211]. Occurring as a result of several mission-related environmental (e.g., radiation, microgravity, excessive exposure to noise and light) and psychosocial stressors (e.g., isolation, homesickness), these symptoms represent a threat to the success of space missions, as they greatly affect astronaut wellbeing [212].…”