Study sheds light on protein's ability to kill rogue cells

In collaboration with Adfero

UK and Australian scientists have shown how an immune system protein called perforin kills rogue cells in the body by punching holes in them so that toxic enzymes can enter and destroy them.

Perforin is often described as the 'bullet' of the immune system, as it is released when harmful or infected cells are detected and helps the body to fight them.

Previous studies have shown that animals with defective perforin are more likely to develop cancers such as leukaemia.

Now, a ten-year study by scientists at Monash University and the Peter MacCallum Cancer Centre in Australia and Birkbeck College in London has revealed the protein's molecular structure and function.

The research, which is published in Nature journal, also showed that parts of the molecule are similar to toxins deployed by bacteria, indicating that this method of making holes in cell membranes may have evolved nearly two billion years ago.

Professor Helen Saibil, who led the Birkbeck College team, revealed: "Perforin is a key weapon in our immune artillery - without it we could not deal with the thousands of rogue cells that turn up in our bodies throughout our lives.

"What we wanted to know was what does perforin look like, what movements does it make and how? To do this, we had to find out its molecular structure and function."

The researchers hope that the findings could inform the development of new treatments for cancer and viral diseases.

For instance, it may be possible to boost the body's levels of perforin to help protect against cancer or combat viruses.

Project leader Professor James Whisstock, from Monash University, revealed: "Perforin is our body's weapon of cleansing. Now we know how it works, we can start to fine-tune it to fight cancer, malaria and diabetes."

Dr Laura Bell, Cancer Research UK's science information officer, said: "New technologies are opening doors for scientists to gain a deeper understanding of some of the basic biological processes linked to cancer development. Work such as this is essential to help researchers find new ways to tackle cancer in the future."

References

  • Law, R. et al (2010). The structural basis for membrane binding and pore formation by lymphocyte perforin Nature DOI: 10.1038/nature09518