Effect of transgene expression of CD40L on the CD40− X-24 plasmacytoma cell line.
Transgene expression of CD40L generates immune protection in the CD40− X-24 plasmacytoma cell line. To evaluate the in vivo effect of CD40L on X-24 cell growth, mice were inoculated SC with X-24 cells (6 × 106) mixed with CL7.1/mCD40L (1 × 106) (white boxes) or CL7.1/neo (1 × 106) (black boxes) fibroblasts. Transgenic expression of CD40L significantly reduces local tumor growth compared with animals receiving tumor cells mixed with CL7.1/neo fibroblasts (A). The tumor size of 6 animals in each group is reported as mean mm ± SD of the 2 maximum diameters. Mice that were vaccinated twice with X-24 cells mixed with CL7.1/mCD40L fibroblasts and challenged 2 weeks later at a distant site with live tumor cells (6 × 106 cells) (broken lines) showed increased tumor-free survival compared with controls (solid lines) (B). Data are derived from 8 animals in the control group and 15 animals in the vaccinated group.
