Effect of transgene expression of CD40L on local tumor growth of CD40+ plasmacytoma cell lines.
Transgene expression of CD40L reduces local tumor growth of CD40+ plasmacytoma cell lines. Data represent the mean ± SD of 5 independent experiments in which tumor proliferation was evaluated after 72 hours of coculture. To evaluate the effect of CD40L on myeloma cell growth in vivo, mice were inoculated SC with sublethally irradiated MPC-11 (panel A) or S107 (panel B) cells mixed (ratio, 2:1) with CL7.1/mCD40L (white boxes) or CL7.1/neo (black boxes) fibroblasts. For both plasmacytoma cell lines, transgenic expression of CD40L significantly reduces local tumor growth compared with control animals receiving tumor cells mixed with CL7.1/neo fibroblasts. The tumor size in the 8 animals in each group is reported as mean millimeters ± SD of the 2 maximum diameters. (C) (D) MPC-11 (panel C) and S107 (panel D) tumor cells cocultured in vitro with irradiated CL7.1/neo (black bars) or CL7.1/mCD40L fibroblasts (gray bars) at different ratios and pulsed with 0.5 μCi (0.018 μBq) methyl-3H-thymidine after 24, 48, and 72 hours of culture have similar proliferative activity.
