UK scientists have used the immune system coupled with a virus found in horses and cattle, to hunt and purge cancer cells through the lymphatic system, a study reveals in Nature Medicine.

Studying mice, the researchers found that the vesicular stomatitis virus (VSV), carried by a type of white blood cell called T cells acted as a ‘cancer hunter’, tracking down tumour cells in the lymph nodes, liver and spleen, and killed them, leaving normal healthy cells unharmed. At the same time, VSV also helped to trigger an immune response against the tumour, significantly improving the anti-cancer effect.

The team hope the findings will eventually lead to the production of new treatments to target some of the most common forms of cancer, including breast, bowel and prostate, as well as improve the development of future cancer vaccines.

This new technique has been developed as the result of an international collaboration between scientists based at Cancer Research UK’s Clinical Centre in Leeds and colleagues at the Mayo Clinic in the US.

As part of their work, the team took the T cells from mice, added a low dose of VSV in the laboratory, and then injected the cells back into mice with cancer. This treatment killed the tumour and stimulated an immune response against the cancer.

Professor Alan Melcher, a Cancer Research UK clinician scientist at the Leeds Clinical Centre, said: “Viruses that can specifically kill tumour cells are a promising new approach to the treatment of cancer, and some are already being tested in patients. In this laboratory study, we show the VSV can be particularly effective in mopping up tumour cells that have broken away from the primary tumour and spread via the lymphatics. By ‘hitchhiking’ on T cells, the virus can travel through the lymphatic system, hunting down and purging lymph nodes and potentially other sites of cancer cells.”

Dr Lesley Walker, Cancer Research UK’s director of cancer information, said:
“The results from these laboratory experiments are encouraging. Cancer becomes most dangerous when it spreads from its original site, so there is great potential in treatments that target this process. The next stage will be to establish what side effects the treatment might have and if it can be made to work in humans as it does in mice.”