Effect of Wortmannin on the proliferation and telomerase activity in stimulated lymphocytes. Purified tonsillar B and T cells from the same donor were pretreated for 30 minutes in the presence of various concentrations of Wortmannin and were stimulated for 2 days with either one of the combination of PDB plus Ca ionophore or soluble anti-IgM Ab plus anti-CD40 MoAb for B cells or PDB plus Ca ionophore or anti-CD3 MoAb for T cells. After the culture, TRAP assay was performed (A).

Relative increase of telomerase activity was determined by densitometric scanning on the autoradiography film by focusing on the ladder bands. Relative intensity was calculated using the positive control with anti-IgM Ab and anti-CD40 MoAb stimulation as 100% and the negative control without any stimulation as 0%. The mean and standard deviation (SD) are given for extracts that were assayed twice. Cell proliferation assay was performed as described in Materials and Methods. The data are shown by the mean ± SD of triplicate assay performed in two separate experiments (B).