POPULATION DOUBLING TIME, PHOSPHATASE ACTIVITY, AND HYDROGEN PEROXIDE GENERATION IN JURKAT CELLS

Authors: Schoene, Norberta; KAMARA, KALATU - UNIVERSITY OF MARYLAND

Submitted to: Free Radical Biology and Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cells in our body use signals to communicate with each other and it is these signals that help keep us healthy and able to fight off diseases. There is a need to know more about how these signals are affected by the foods we eat so that nutritional scientists can design more effective, health-promoting diets. Many of the antioxidant components in foods are thought to influence signal generation in a beneficial way. One way to study how antioxidants work is to grow cells in flasks and observe how signals are affected by the supply of antioxidants fed to the cells. We have found two kinds of cells that are similar in many ways yet produce different amounts of an oxidative signal. The oxidative signal is known to be injurious in high amounts and may lead to even further harmful responses in the cells. These cells provide us with excellent models to better understand how antioxidants work as disease-fighters. Information from these experiments benefits both researchers studying signal generation in cells and nutritional scientists making recommendations on the kinds and amounts of antioxidants to be included in heathful diets consumed by the US population.

Technical Abstract: Results of a study to characterize growth characteristics and related biochemical parameters in two clones of a T cell leukemic line are described in this communication. Wurzburg cells had significantly shorter population doubling times compared to the parental Jurkat cells (16.6 +/- 2.0 h and 20.7 +/- 2.2 h, respectively; mean+/-SD, p<0.0001, n=20). In addition, total phosphatase activity was significantly decreased (p<0.006) and hydrogen peroxide production was significantly increased (p<0.002) in Wurzburg cells compared to Jurkat cells. That the cell line with the faster growth rate should have these latter two properties is not unexpected. The positive effects of increased kinase activity (less phosphatase activity) and hydrogen peroxide on proliferative cellular responses in T cells has been well established. As originally described, Wurzburg cells were distinguished from Jurkat cells by their lack of CD45, a membrane protein tyrosine phosphatase, and their positive response to hydrogen peroxide-stimulation of NF-kB activation. We propose that these two clones, with their distinguishing characteristics, can be used to advantage in experiments designed to study the effects of antioxidants on signaling pathways that control cell life and death.