It took a further 27 years before the structure of the virus was observed for the first time and in doing so took the Noble prize winners' discovery forward.
In fact, in what was also a world first, French scientists from Inserm and University of Tours observed its structure under an electron microscope in 2016.
“It’s an exceptional virus and a remarkable discovery. Normally, observation plays a key role in virus discovery. However, in this case, for 25 years after its discovery the structure of the virus could be deduced only through molecular biology,” Dr Phillipe Roingeard, professor of medicine at the University of Tours, told RFI.
The reason why the HCV, which belongs to the flavivirus community, remained so elusive was because of its unique ability to mask itself as lipid particles such as cholesterol. Moreover, it is present in much smaller amounts compared to the Hepatitis B virus. And unlike other viruses, it cannot be grown in cells in a laboratory.
“As a result, the virus remains hidden to the immune system of an infected person,” Dr Roingeard said.
The French researchers started working on a new technique from 2011 to observe the virus under an electron microscope.
For the first time in history, the Hepatitis C virus can now be cured. The 2020 Medicine Laureates’ discoveries revealed the cause of the remaining cases of chronic hepatitis and made possible blood tests and new medicines that have saved millions of lives.#NobelPrize pic.twitter.com/hqJK1uWX3u
— The Nobel Prize (@NobelPrize) October 5, 2020
Unlike a conventional microscope which uses light, an electron microscope uses a beam of electrons to observe a microscopic object.
An electron microscope is thousands of times more powerful than a typical lab microscope.
Researchers from all over the world had tried observing the viral structure under electron microscopes but to no avail.
“The virus is fragile. It would get damaged during the standard techniques of sample purification and centrifugation processes. It wasn’t possible to observe the virus without manipulating it,” Dr Roingeard explained.
However, the French team managed to overcome these obstacles. Their technique consisted of trapping the virus with antibodies on the electron microscope grids. It took several attempts during the five years before they managed to obtain the first direct image of the structure of the virus in 2016.
The structure observed by Dr Roingeard and his team corresponds perfectly to the one predicted by scientists based on molecular biology. “The virus has a strange structure, similar to that of a lipid. This is something you don’t see in any other viruses,” he added.
