Overcoming obstacles To see whether they could overcome the 'camouflage' of such escaped tumors and turn them into recognizable targets for the immune system, the researchers examined several strategies. One of them involved the forced high expression of TAP1, a protein involved in the transport of antigens to the cell surface. This is a way to artificially raise the immunogenicity of the tumors. Doing this in escaped tumor cells resulted in eventual rejection of all tumors when those cells were transplanted into immune-competent recipient mice. These mice were also immune to subsequent challenges with tumor cell transplants that had not been manipulated to express high levels of TAP1.
More immunogenic tumors cause a stronger immune response.
The fact that this can lead to tumor rejection in the transplant models suggests that raising the level of the tumor-specific immune response alone might be sufficient to turn the immune system into an effective weapon against the tumor. Experiments are currently under way to test whether the results described here could form the basis for cancer immuno-therapy. Founded in 1953, the Cancer Research Institute hasfocused on the rapidly expanding field of cancer immunology, which seeks to utilize and strengthen the immune system's innate ability to combat the disease. IFN g and lymphocytes prevent primary tumour development and shape tumour immunogenicity. Nature 410, 1107-1111, 2001.