GM-CSF as immunostimulant

Somatix Therapy Corp. said that in mouse studies GM-CSF genes inserted into inactivated melanoma cells conferred systemic immunity for at least two months in 80 percent of animals challenged with live melanoma cells. The study, led by researchers at the Whitehead Institute for Biomedical Research, was published in the latest issue of the Proceedings of the National Academy of Sciences.

The researchers compared the activity of 10 cytokines - IL-2, IL-4, IL-5, IL-6, GM-CSF, gamma interferon, ICAM-1, CD-2, IL-1ra and TNF-alpha - against melanoma challenge and found that GM-CSF was the most powerful immunostimulant. Subcutaneous injection of irradiated melanoma cells expressing GM-CSF provided systemic protection against unmodified melanoma cells and also led to the rejection of small, pre-established tumors. Cells expressing GM-CSF also provided protection against other tumor types, including lung, kidney, colon and fibrosarcoma...