Experiment MIA

The goal of this experiment is to determine the effect of microgravity on both the ability of adherent monocytes to migrate on a surface (Motion), as well as to interact with T-cells (Interact). Monocyte locomotion is important in immune function, since monocytes need to bind to tissue surfaces and then migrate through them. Additionally, interaction of monocytes with T-lymphocytes is important for the co-stimulatory signal (2nd signal). The experiment consists of two components: In the 'Motion' experiment a monocyte cell line will be incubated on a colloid gold substrate. As the monocytes migrate they remove the colloid gold, leaving a track on the substrate which records the cell motion. The experiment will be terminated in-flight by addition of formaldehyde fixative. The 'Interact' experiment will mix T-cell and monocyte cells and samples will be fixed at two time intervals. Post-flight, the clustering of T-cells with monocytes as well as the distribution of adhesion receptors on each cell type will be observed by microscopy.

Objective:

Investigate the interactions of monocytes and T-lymphocytes (calf serum cells) under microgravity.

Tasks:

Investigate the interactions of monocytes and T-lymphocytes to test the hypothesis that reduced cell-cell interactions might be one of the reasons for observed depression in lymphocyte in-vitro activation under micro-gravity.
Study the motility and changes in the cytoskeletal structures of monocytes.