Figure 4
Effect of direct p21 gene transfer in T cells on mitogen induced proliferation. Three cell lines each from cells transfected with CD3p21 sense and CD3p21 antisense plasmid DNA were cultured with and without PHA for 4 h for IL-2 mRNA expression and 72 h (last 16 h with 3H-thymidine) for the proliferation assay. The results (A) demonstrate that p21 overexpressing EL4 T cells (CD3Sp21) did not respond to the mitogenic stimulus, whereas cells transfected with antisense plasmid DNA (CD3ASp21) proliferated significantly higher compared to untreated cells. *** = p < 0.02 (EL4 CD3ASp21 cells control vs PHA), ** = p < 0.03 EL4CD3Sp21 PHA vs CD3Asp21 PHA) and * = p < 0.05 control EL4 cells vs PHA. The mitogenic response was reflected in IL-2 mRNA expression by these cells. There was no difference in IL-2 mRNA expression between untreated and cells cultured with PHA for CD3Sensep21 plasmid DNA transfected cells (B, lanes 1 with a and without PHA). In sharp contrast, in cells transfected with CD3Antisensep21 plasmid DNA, PHA treatment resulted in a significant increase in IL-2 mRNA expression compared to the untreated cells.