Suppression of human anti-inflammatory plasma cytokines IL-10 and IL-1RA with elevation of proinflammatory cytokine IFN-gamma during the isolation of the Antarctic winter.
Cellular immune function has been shown to be decreased and latent virus shedding to be increased in human beings isolated during the Antarctic winter, a model used for assessing some effects of space flight. However, the balance of proinflammatory (IFN-gamma) and anti-inflammatory (IL-10 and IL-1RA) cytokines has not previously been evaluated. We therefore sought to determine whether isolation during the Antarctic winter would alter the proinflammatory and anti-inflammatory cytokine balance. Cytokine levels were measured with ELISA in monthly plasma samples from January through September 1999 in 21 study subjects in the Antarctic and 7 control subjects on Macquarie Island. There was a significant time-dependent increase in plasma IFN-gamma (P =.039) as well as decreases in IL-10 (P =.042) and IL-1RA (P =.053) in the study subjects compared with the control subjects. The study subjects also had significantly increased plasma IFN-gamma levels (P < or =.045) but decreased IL-10 and IL-1RA levels (P < or =.036) at individual time points of isolation. Isolation of human beings in the Antarctic appears to shift the plasma cytokine balance toward a proinflammatory profile. These observations are consistent with T-cell activation that might be due to activation of latent viruses, and they could hold importance for determining the risks of space flight.
Shearer
William T
WT
Baylor College of Medicine, Houston, USA.
Lee
Bang-Ning
BN
Cron
Stanley G
SG
Rosenblatt
Howard M
HM
Smith
E O'Brian
EO
Lugg
Desmond J
DJ
Nickolls
Peter M
PM
Sharp
Robert M
RM
Rollings
Karl
K
Reuben
James M
JM
D000864:Antarctic Regions; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D053590:Interleukin 1 Receptor Antagonist Protein; D016753:Interleukin-10 / Q000037:antagonists & inhibitors* / Q000097:blood; D018664:Interleukin-12 / Q000096:biosynthesis; D012621:Seasons; D012795:Sialoglycoproteins / Q000037:antagonists & inhibitors* / Q000097:blood
C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D012795:Sialoglycoproteins; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma