video transcript

Remarkable high-speed video of the world's most benevolent serial killer - the T cell. T cells live in the bloodstream as part of the immune system, helping defend the body against viral infections and cancer. Wellcome Trust principal research fellow, Professor Gillian Griffiths, says there are few killers more efficient than the T cell. SOUNDBITE (English) PROFESSOR GILLIAN GRIFFITHS, WELLCOME TRUST PRINCIPAL RESEARCH FELLOW, SAYING: "What you'll see is these little packages in pink focus towards the cancer cell, the killer T cell recognises him. Almost immediately it curls up, it rounds up and dies, it's an amazingly effective killer cell that's found in your bloodstream and what you'll notice now is that actually the killer cell, once it's killed, it can detect that and it moves off and it kills again and again and again. It's a serial killer." T cells are less than a tenth of the diameter of a strand of hair - but tremendously powerful, killing cancer cells, while leaving surrounding healthy cells unharmed. But they don't always work as they're supposed to. Genetic mutations in some people leave them vulnerable to diseases where T-cells attack healthy cells often with fatal outcomes. In a bid to prevent these disorders and discover exactly how T cells work, Griffiths's team at Cambridge University are examining the blood proteins of people with genetic mutations. PHD student Yvonne Hackmann..... SOUNDBITE (English) YVONNE HACKMANN, PHD STUDENT, SAYING: "This is one of the proteins we work on that we found is important for a killer cell to kill a cancer cell and by solving the structure of this protein we can now see exactly where the human mutations are." Genetic mutations give rise to a range of primary immunodeficiencies, compromising the body's ability to fight infectious disease. Here in pink is a killer cell with such a mutation. The cell fails to release its package of killing proteins and is overwhelmed by the green cancer cell. Research assistant Sam Grieve is looking at another protein. SOUNDBITE (English) SAM GRIEVE, RESEARCH ASSISTANT, SAYING: "Today I'm doing an experiment to see whether the mutations that we've found in the protein I'm looking at stop the interaction with another protein, and how this can stop the T cells killing." The team wants to identify ways to exploit our natural immunity to target cancer, via the killer T cell. They'd also like to find ways of stopping the T Cells killing healthy cells, as they do when organs are transplanted into the body. Griffiths is hopeful. SOUNDBITE (English) PROFESSOR GILLIAN GRIFFITHS, WELLCOME TRUST PRINCIPAL RESEARCH FELLOW AT CAMBRIDGE INSTITUTE FOR MEDICAL RESEARCH, SAYING: "What we're hoping with our research is that by understanding at the molecular level how these killer cells work that we can improve their ability to work against cancer more effectively and that we can also manage to turn them down when they're working inappropriately in autoimmune diseases." If the team is successful, the serial killing T Cell may become an even more useful tool in stopping cancers and other deadly diseases in their tracks, before they have a chance to grow. Jim Drury, Reuters