TY - JOUR
T1 - NK cell function is impaired during long-duration spaceflight
AU - Bigley, Austin B.
AU - Agha, Nadia H.
AU - Baker, Forrest L.
AU - Spielmann, Guillaume
AU - Kunz, Hawley E.
AU - Mylabathula, Preteesh L.
AU - Rooney, Bridgette V.
AU - Laughlin, Mitzi S.
AU - Mehta, Satish K.
AU - Pierson, Duane L.
AU - Crucian, Brian E.
AU - Simpson, Richard J.
N1 - Funding Information:
This work was supported by NASA Grants NNX12AB48G, NNX16AB29G, and NNX16AG02G to R. J. Simpson, a NASA Human Research Program grant to B. E. Crucian, and a National Space Biomedical Research Institute postdoctoral fellowship (NCC 9-58) to A. B. Bigley.
Publisher Copyright:
© 2019 American Physiological Society. All rights reserved.
PY - 2019/1/17
Y1 - 2019/1/17
N2 - Maintaining astronaut health during space travel is paramount for further human exploration of the solar system beyond Earth’s orbit. Of concern are potential dysregulations in immunity, which could increase the likelihood of cancer and latent viral reactivation. Natural killer (NK) cells are critical effectors of the innate immune system, and their function and phenotype are important to immunosurveillance of nascent tumors and latent viral infections. We compared changes in NK cell phenotype and function in eight crew members who completed an ~6-mo mission to the International Space Station (ISS) with healthy controls who remained on Earth. Assessments were made before (180 and 60 days before launch), during [flight day 90 days (FD90) and 1 day before return (R1)], and after the mission (at R0, R18, R33, and R66). These samples, plus an additional in-flight sample (FD180), were collected from a crew member who spent 340 days (~1 yr) on the ISS. NK cell cytotoxic activity (NKCA) against K562 leukemia targets in vitro was reduced by ~50% at FD90 in ISS crew but not controls. This decrease was more pronounced in “rookie” compared with “veteran” crew members. The ~1-yr mission crew member did not show declines in NKCA against K562 until late in the mission (R1 and R0). NK cell numbers, expression of activating and inhibitory receptors, target cell binding, and expression and degranulation of perforin and granzyme B were unaltered with spaceflight. Similarly, when we exposed an immortalized NK cell line (NK-92) to sera collected at different mission time points (before, during, and after flight), there was no effect on NKCA. This is the first study to report impaired NK cell function during long-duration space travel. Countermeasures may be needed to mitigate immune system impairment in exploration class mission crew during long-duration spaceflight missions.
AB - Maintaining astronaut health during space travel is paramount for further human exploration of the solar system beyond Earth’s orbit. Of concern are potential dysregulations in immunity, which could increase the likelihood of cancer and latent viral reactivation. Natural killer (NK) cells are critical effectors of the innate immune system, and their function and phenotype are important to immunosurveillance of nascent tumors and latent viral infections. We compared changes in NK cell phenotype and function in eight crew members who completed an ~6-mo mission to the International Space Station (ISS) with healthy controls who remained on Earth. Assessments were made before (180 and 60 days before launch), during [flight day 90 days (FD90) and 1 day before return (R1)], and after the mission (at R0, R18, R33, and R66). These samples, plus an additional in-flight sample (FD180), were collected from a crew member who spent 340 days (~1 yr) on the ISS. NK cell cytotoxic activity (NKCA) against K562 leukemia targets in vitro was reduced by ~50% at FD90 in ISS crew but not controls. This decrease was more pronounced in “rookie” compared with “veteran” crew members. The ~1-yr mission crew member did not show declines in NKCA against K562 until late in the mission (R1 and R0). NK cell numbers, expression of activating and inhibitory receptors, target cell binding, and expression and degranulation of perforin and granzyme B were unaltered with spaceflight. Similarly, when we exposed an immortalized NK cell line (NK-92) to sera collected at different mission time points (before, during, and after flight), there was no effect on NKCA. This is the first study to report impaired NK cell function during long-duration space travel. Countermeasures may be needed to mitigate immune system impairment in exploration class mission crew during long-duration spaceflight missions.
KW - Astronauts
KW - Immunity
KW - Isolation and confinement
KW - Microgravity
KW - Space exploration
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U2 - 10.1152/japplphysiol.00761.2018
DO - 10.1152/japplphysiol.00761.2018
M3 - Article
C2 - 30382809
AN - SCOPUS:85064211579
VL - 126
SP - 842
EP - 853
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 4
ER -