ASGSB 1999 Annual Meeting Abstracts

ADHESION AND MIGRATION OF LYMPHOCYTES CULTURED IN ROTATING WALL VESSELS. A.J. Bergman and K. Zygourakis. Departments of Chemical Engineering and Bioengineering, Rice University, Houston.

Microgravity may affect lymphocyte function by altering the forces these cells experience as they circulate in the body. To study these effects, we have evaluated the migration and adhesion behavior of Jurkat cells (a T-lymphoblastoid cell line) cultured for up to 10 days both in a low-shear rotating wall vessel (RWV) and statically.

At 2-day intervals, cells were removed from culture and plated on polystyrene plates coated with fibronectin. Cell migration was evaluated by placing these plates in a microincubator located on the motorized stage on an inverted light microscope. Cell trajectories were reconstructed by monitoring over 7 hours the position of individual cells at 10-minute intervals. Cell adhesion was characterized by placing the cells in a parallel plate flow chamber and quantifying the shear stress required to detach the cells from the surface. Finally, fibronectin receptor expression was evaluated using flow cytometry.

We observed that cells cultured in the RWV exhibited a significantly higher cell migration speed than cells cultured statically on fibronectin-coated polystyrene surfaces after 4-10 days of culture. However, no significant differences were observed in cell-substratum adhesion strength between cells cultured in the RWV and statically. Although a significant increase was observed in the expression of the fibronectin 5 receptor integrin subunit, blocking of this receptor did not significantly effect the cell migration speed of Jurkat cells. Also, treating the cells with A2C, a membrane ordering agent, did not effect cell migration speeds. However, cells cultured statically showed a significantly more rounded morphology than cells cultured in the RWV.

In conclusion, our results show that increased migration speed of Jurkat cells cultured in the RWV versus static cell culture is likely not due to modulation of fibronectin receptor number or membrane fluidity, but rather to changes in the cytoskeleton function and cell morphology.

(This work was supported by the NASA grant #NAGW-5007)

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