BSE: Science & research - TSE Diagnostics - The infectious agent
Although the exact nature of the infectious agent that produces TSE disease is still unknown, the ‘Prion Hypothesis’, which states that an abnormal form of the prion protein (PrPSc) is the infectious agent, is widely accepted. It is known is that PrPSc is found in the brain or other organs of animals that have died from a TSE disease.
However, there are uncertainties about this hypothesis including the still unknown function of the normal prion protein found in the body (PrPc) and the existence of several alternative hypotheses. Defra has funded some research into these alternative theories in the past and continues to fund research investigating the reliability of PrPSc as a marker for TSE infectivity.
The identification of the structure and mechanism of action of the infectious agent for TSEs would bring about improved diagnostic techniques and allow the development of treatments for stopping disease progression.
Overview of research in this area
Recent work includes:
- Examining whether different-sized aggregates of the abnormal prion protein differ in their ability to cause disease (project SE2012).
- Investigating if a correlation exists between infectivity levels of TSE in brain tissue as measured by mouse bioassay and the levels of PrPSc detected by standard biochemical tests (project SE2007).
- Examining whether PrPSc is a reliable marker for infectivity by studying mouse models where levels of PrPSc and infectivity do not correlate (projects SE1437, SE1790)
Past projects have examined different hypotheses but have not returned any conclusive results:
- Whether TSEs are caused by nucleic acids, ie. segments of RNA (project SE1770).
- Looking for viruses associated with TSE disease.
Page last modified: 7 March, 2008