Journal of Applied Physiology, Vol 73, Issue 2 196S-200S, Copyright © 1992 by American Physiological Society
Effect of spaceflight on natural killer cell activity
M. P. Rykova, G. Sonnenfeld, A. T. Lesnyak, G. R. Taylor, D. O. Meshkov, A. D. Mandel, A. E. Medvedev, W. D. Berry, B. B. Fuchs and I. V. Konstantinova
Institute of Biomedical Problems, Academy of Medical Sciences, Moscow, Russia.
The effects of spaceflight on immune cell function were determined in rats
flown on COSMOS 2044. Control groups included vivarium, synchronous, and
antiorthostatically suspended rats. The ability of natural killer cells to
lyse two different target cell lines was determined. Spleen and bone marrow
cells obtained from flight rats showed significantly inhibited cytotoxicity
for YAC-1 target cells compared with cells from synchronous control rats.
This could have been due to exposure of the rats to microgravity.
Antiorthostatic suspension did not affect the level of cytotoxicity from
spleen cells of suspended rats for YAC-1 cells. On the other hand, cells
from rats flown in space showed no significant differences from vivarium
and synchronous control rats in cytotoxicity for K-562 target cells.
Binding of natural killer cells to K-562 target cells was unaffected by
spaceflight. Antiorthostatic suspension resulted in higher levels of
cytotoxicity from spleen cells for 51Cr-labeled K-562 cells. The results
indicate differential effects of spaceflight on function of natural killer
cells. This shows that spaceflight has selective effects on the immune
response.
