HQ Team
July 6, 2023: The Hepatitis C virus wears a “mask” and remains hidden to evade the human immune system to cause inflammation and scarring of the liver, Dutch researchers found.
The mask helps the virus to remain hidden while making copies of itself to infect new cells. The mask cloaks the virus in the form of a molecule already in human cells.
Disguised by the molecule, the immune system confuses the virus with something harmless that needn’t be reacted to, according to researchers at the University of Copenhagen’s Faculty of Science.
The discovery may help how to track and treat viral diseases in general.
Hepatitis C affects about 50 million people globally and is one of the most studied viruses in the world. In the worst case, it may cause liver cancer.
‘Bit of mystery’
“How the Hepatitis C virus manages to hide in our liver cells without being detected by the immune system has always been a bit of a mystery,” said associate professor, Jeppe Vinther of the Department of Biology, who together with associate professor Troels Scheel and Prof Jens Bukh from Copenhagen Hepatitis C Program headed the research.
“Our revelation of the virus’ masking strategy is important, as it could pave the way for new ways of treating viral infections. And it is likely that other types of viruses use the same trick.”
The study was published in the scientific journal Nature.
The mask used by the hepatitis virus to hide in human cells is called FAD (Flavin adenine dinucleotide), a molecule composed of Vitamin B2 and the energy-carrying molecule ATP, the authors wrote in the journal.
FAD is vital for human cells convert energy. The FAD molecule’s importance and familiarity with our cells make it ideal camouflage for a malicious virus.
Needed proof
For several years, the research team had a good idea that FAD was helping the virus hide in infected cells, but they lacked a clear way to prove it.
To solve the challenge, they turned to Arabidopsis, a well-known experimental plant among researchers.
“We were getting desperate to find a way to prove our hypothesis, which is when we purified an enzyme from the Arabidopsis plant that can split the FAD molecule in two,” said Anna Sherwood from Department of Biology, who together with Lizandro Rene Rivera Rangel are first authors of the study.
Using the enzyme, the researchers were able to split the FAD and prove that the hepatitis C virus used it as a mask.
Like both the corona virus and influenza virus, Hepatitis C is an RNA (ribonucleic acid) virus. Its genetic material consists of RNA that must be copied once the virus enters its host organism.
Other viruses
New RNA copies are used to take over new cells, and one end of the RNA’s genetic material is masked by the FAD.
Other RNA viruses may use similar masking techniques to spread without being detected by cellular control systems, Jeppe Vinther said.
Researchers have found another virus that uses the same masking techniques to spread without detection by cellular control systems. And, there are likely more.
“All RNA viruses have the same need to hide from the immune system and there is a good chance that this is just the beginning. Now that we’re attuned to this trick, it opens up the possibility of developing new and perhaps improved methods of tracking and treating viral infections in the future,” said Jeppe Vinther.
