The virus responsible for most cases of cervical cancer has a serious weakness which may provide hope for new treatments for the disease.
Human Papillomavirus (HPV), a virus which causes several types of cancer but is particularly associated with cervical cancer, has developed clever ways of hiding in the body, but researchers at the University of Leeds have found that its ability to trick the body's first line of defence leaves it vulnerable to attack from a second defence system.
When viruses enter cells, they produce proteins to assist their growth and replication, and the body's immune system is programmed to recognise and attack these non-native proteins.
Professor Eric Blair of the University's Faculty of Biological Sciences and Dr Graham Cook from the Leeds Institute for Molecular Medicine have been specifically looking at one of the proteins produced by HPV, called E7, and have discovered that it suppresses markers on the cell surface, making infected cells much less visible to T cells, one of the body's key defence systems.
“T cells can normally tell when there are molecules in the body that shouldn't be there and activate an immune response,” says Professor Blair. “But HPV uses the E7 protein to hide from them. We've always known the virus has clever ways of defending itself, but we now know how one of its main defence mechanism works.”
However, in a twist that offers hope for the development of potential new therapies for cervical cancer, Professor Blair and Dr Cook have also discovered that this subterfuge may be the virus's downfall.
Cells without surface protein markers are targeted by another of the body's white blood cell armoury, Natural Killer cells - cellular assassins, which when activated, release specialised enzymes into target cells to kill them.