Natural Killer Cell Activity in Microgravity (NKA)
Research Area: Cellular Biology
Expedition(s): 13
Principal Investigator(s): ● Lyudmila Buravkova, Institute of Medical and Biological
Problems of Russian Academy of Sciences, Russia
RESEARCH OBJECTIVES
The objective of the Natural Killer Cell Activity in Microgravity (NKA) flight experiment is to
assess NK cytotoxic activity during co-cultivation of lymphocytes and myoblast K-562 cells
under microgravity.
RESULTS
The level of natural killer (NK) cytotoxic activity was measured during co-cultivation of human
lymphocytes and target cells (K- 562) in microgravity. Flight experiments were carried out using
special instrumentation, the Fibroblast-1 cassettes, in the frame of Russian scientific program
during 6 International Space Station (ISS) missions, which involved cooperation with European
Space Agency (ESA). Lymphocyte suspensions from human venous blood were used in
experiments during short-term flights on 6 ISS missions. Russian crew members performed the
experiments after Soyuz docking. The first step was mixing lymphocytes and 3H-labeled K-562
cells and their incubation at 37°C during 24 hours; the second step was filtration of the cell
suspension. The frozen medium and filters were analyzed for the cytokine level and cytotoxic
activity after landing. It was found that lymphocytes with different basal levels of cytotoxic
activity kept the ability of recognizing and lysing malignant cells. In microgravity, cytotoxity
increased to 160% of the basal levels. Donor individual features modulated the magnitude of
the increase. The measurement of interleukin levels (TNF-α, IL-1, IL-2) in medium showed that
synthesis of TNF-α increased during cell co-cultivation in microgravity. The level of IL-2 was very
low in flight and ground control samples. The production of IL-1 by lymphocytes decreased
after in-flight incubation. The results indicate that microgravity did not disturb the cytotoxic
function of immune cells in vitro during 24-hour incubation with specific target cells.
PUBLICATION(S)
Buravkova LB, Grigorieva OV, Rykova MP, Grigoriev AI. Cytotoxic activity of natural killer cells in
vitro under microgravity. Biological Sciences. July-August 2008;421:275-277. doi:
10.1134/S0012496608040169. [Also: Grigorieva OV, Buravkova LB, Rykova MP. Cytotoxic
activity of NK lymphocytes in vitro under microgravity. 26th Annual International Gravitational
Physiology Meeting, Cologne, Germany; 2005.]
Buravkova LB, Grigorieva OV, Rykova MP. The effect of microgravity on the in vitro NK cell
function during six International Space Station Missions. Microgravity Science and
Technology.2007;19(5-6):145-147. doi: 10.1007/BF02919470.
Buravkova LB, Romanov Y, Rykova MP, Grigorieva OV, Merzlikina N. Cell-to-cell interactions in
changed gravity: Ground-based and flight experiments. Acta Astronautica. July 2005;57(2-8):67-
- doi: 10.1016/j.actaastro.2005.03.012. [Also: Buravkova LB, Romanov Y, Grigorieva OV,