Effect of sls-2 space flight on immunological parameters of
rats.
Lesnyak, Andrei, Gerald Sonnenfeld, Leann Avery, Irina Konstantinova,
Marina Rykova, Dmitrii Meshkov, Tatyana Orlova.
State Research Center -- Institute of Biomedical Problems, Moscow
123007, Russia, Department of General Surgery Research, Carolinas
Medical Center, Charlotte, NC 28232-2861, USA, NASA Ames Research
Center, Moffett Field, CA 94035, USA, Gamaleya Institute of
Epidemiology and Microbiology, Moscow, Russia
APStracts 2:0370A, 1995.
During the Space Shuttle SLS-2 mission rats were dissected in space
and biosamples were returned to the Earth for analysis. Immunological
studies addressed the kinetics of T-lymphocyte proliferative
responses, cytotoxic activity of natural killer cells, and cytokine
production. Experiments were performed using spleen and bone marrow
of rats dissected before flight, during flight, immediately after
landing of the Space Shuttle (L + 0) or 14 days after landing (L +
14), as well as respective control animals. Each group consisted of 5
Sprague-Dawley male rats. It was demonstrated that T-lymphocyte
activity of rats dissected in flight was significantly decreased when
compared to the controls. This was observed during 48-, 72- and 96
-hour cultivation and stimulation with the following mitogenic
stimuli: concanavalin A (Con A) 0.1, 1.0, and 10.0 mg/ml,
phytohemagglutinin (PHA) 2.5 mg/ml, and interleukin-2 (IL-2) 1 U/ml.
The cell proliferation rate in rats dissected immediately after
landing did not decrease, while that in rats dissected at L+14
increased. The activity of spleen natural killer cells was reduced in
response to 51Cr-labeled target cells during flight (YAC-1 and K-562)
and after flight (YAC-1). At L+14, their activity returned to normal.
Another technique employed to measure natural cytotoxicity, using 3H
-uridine labeled target cells and RNase, did not reveal any
differences between control and experimental groups. In bone marrow,
the activity of natural killer cells did not vary significantly. The
production of interleukin-1 (IL-1), IL-2, tumor necrosis factor -
alpha (TNF-alpha) and tumor necrosis factor - beta (TNF-beta) in
spleen cell cultures of the flight rats was reduced. At L+0, IL-1 and
TNF-beta remained lowered, while TNF-alpha was increased. At L+0,
interferon-alpha (IFN-alpha) and interferon-gamma (IFN-gamma) were
diminished. In summary, cell-mediated immunity in rats was
significantly suppressed during flight. The time course variation of
immune parameters after flight suggests that the changes may truly
indicate a response of the immune system to space flight conditions
that could increase over time.
Received 13 February 1995; accepted in final form 9 August 1995.
APS Manuscript Number A172-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 August 1995.