The Effect Of Interleukin-2 On The Proliferation Of Neural Stem Cell

Objective:To investigate the effect of interleukin-2 on the proliferation of neural stem cell.Methods:Cells were harvested from subventricular zone and hippocampus of embryonic rats. After primary culture and passage, immunocytochemistry staining of nestin was carried out to determine whether they are neural stem cells. Stem cells were then divided into four groups. Interleukin-2 was administrated to culture medium of three experimental groups, whose final concentration was 50ng/ml, 100ng/ml and 150ng/ml respectively, while no IL-2 in the control group. After three days culturing, BrdU was administrated to all medium. A day later, immunocytochemistry staining of BrdU was carried out and positive and negative cells were counted under microscope to calculate the proliferation rates of neural stem cells of each group.Results:At the first day of primary culture, most cells attached to the floor. All of them were small and round in shape, without large projection. After 4-5 days, a lot of attached cells died; the surviving floating cells began to proliferate and form a round shape (Neurosphere). At about the seven day of primary culture, neurospheres contained several hundreds of cells. By immunocytochemisty, we found most cells in neurospheres were nestin positive, indicating that they were neural stem cells. IL-2 could promote the proliferation of neural stem cell in a dose-dependent manner. In all groups, the proliferation rate of neural stem cells with IL-2 150ng/ml in medium is the highest, while the proliferation rate is lower than that when the concentration of IL-2 is 50 ng/ml, but still higher than control group. The proliferation rate of neural stem cells with IL-2 100ng/ml in medium is just between the former two experimental groups and is significantly higher than control group.Conclusion:IL-2 at a certain concentration promotes the proliferation of neural stem cell.