USE OF AN ADAPTABLE CELL-CULTURE KIT FOR PERFORMING LYMPHOCYTE AND MONOCYTE CELL-CULTURES IN MICROGRAVITY

The results of experiments performed in recent years on board faciliti es such as the Space Shuttle/Spacelab have demonstrated that many cell systems, ranging from simple bacteria to mammalian cells, are sensiti ve to the microgravity environment, suggesting gravity affects fundame ntal cellular processes. However, performing well-controlled experimen ts aboard spacecraft offers unique challenges to the cell biologist. A lthough systems such as the European 'Biorack' provide generic experim ent facilities including an incubator, on-board 1-g-reference centrifu ge, and contained area for manipulations, the experimenter must still establish a system for performing cell culture experiments that is com patible with the constraints of spaceflight. Two different cell cultur e kits developed by the French Space Agency, CNES, were recently used to perform a series of experiments during four flights of the 'Biorack ' facility aboard the Space Shuttle. The first unit, Generic Cell Acti vation Kit 1 (GCAK-1), contains six separate culture units per cassett e, each consisting of a culture chamber, activator chamber, filtration system (permitting separation of cells from supernatent in-flight), i njection port, and supernatent collection chamber. The second unit (GC AK-2) also contains six separate culture units, including a culture, a ctivator, and fixation chambers. Both hardware units permit relatively complex cell culture manipulations without extensive use of spacecraf t resources (crew time, volume, mass, power), or the need for excessiv e safety measures. Possible operations include stimulation of cultures with activators, separation of cells from supernatent, fixation/lysis , manipulation of radiolabelled reagents, and medium exchange. Investi gations performed aboard the Space Shuttle in six different experiment s used Jurkat, purified T-cells or U937 cells, the results of which ar e reported separately. We report here the behaviour of Jurkat and U937 cells in the GCAK hardware in groundbased investigations simulating t he conditions expected in the flight experiment. Several parameters in cluding cell concentration, time between cell loading and activation, and storage temperature on cell survival were examined to characterise cell response and optimise the experiments to be flown aboard the Spa ce Shuttle. Results,indicate that the objectives of the experiments co uld be met with delays up to 5 days between cell loading into the hard ware and initial in flight experiment activation, without the need for medium exchange. Experiment hardware of this kind, which is adaptable to a wide range of cell types and can be easily interfaced to differe nt spacecraft facilities, offers the possibility for a wide range of e xperimenters successfully and easily to utilise future flight opportun ities. J. Cell. Biochem. 70:252-267, 1998. (C) 1998 Wiley-Liss, Inc.