Antibody responses to bacteriophage phi X-174 in human subjects exposed to the antarctic winter-over model of spaceflight.
BACKGROUND
It has been proposed that exposure to long-term spaceflight conditions (stress, isolation, sleep disruption, containment, microbial contamination, and solar radiation) or to ground-based models of spaceflight will alter human immune responses, but specific antibody responses have not been fully evaluated.


OBJECTIVE
We sought to determine whether exposure to the 8-month Antarctic winter-over model of spaceflight would alter human antibody responses.


METHODS
During the 1999 Australian National Antarctic Research Expeditions, 11 adult study subjects at Casey, Antarctica, and 7 control subjects at Macquarie Island, sub-Antarctica, received primary and secondary immunizations with the T cell-dependent neoantigen bacteriophage phi X-174. Periodic plasma samples were analyzed for specific antibody function.


RESULTS
All of the subjects from Casey, Antarctica, cleared bacteriophage phi X-174 normally by 1 week after primary immunization, and all had normal primary and secondary antibody responses, including immunologic memory amplification and switch from IgM to IgG antibody production. One subject showed a high normal pattern, and one subject had a low normal pattern. The control subjects from Macquarie Island also had normal immune responses to bacteriophage phi X-174.


CONCLUSIONS
These data do not support the hypothesis that de novo specific antibody responses of subjects become defective during the conditions of the Antarctic winter-over. Because the Antarctic winter-over model of spaceflight lacks the important factors of microgravity and solar radiation, caution must be used in interpreting these data to anticipate normal antibody responses in long-term spaceflight.
Shearer
W T
WT
Baylor College of Medicine, Houston, Texas, USA.
Lugg
D J
DJ
Rosenblatt
H M
HM
Nickolls
P M
PM
Sharp
R M
RM
Reuben
J M
JM
Ochs
H D
HD
D000328:Adult; D000864:Antarctic Regions / Q000453:epidemiology; D000914:Antibodies, Viral / Q000276:immunology; D000917:Antibody Formation; D000956:Antigens, Viral / Q000276:immunology; D001435:Bacteriophages / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012621:Seasons; D013026:Space Flight
D000914:Antibodies, Viral; D000956:Antigens, Viral