Currently, there is no vaccine available for the Hepatitis C virus infection, which affects over 130 million people globally and nearly 250,000 Canadians. Available treatments include antivirals, but they are quite expensive and are not readily available in developing countries, where the disease is most prevalent.
A team of virologists at the Institut national de la recherche scientifique (INRS) determined the critical role of a cellular protein in the progression of Hepatitis C virus infection. Speculations are that it may help in opening new ways for more effective treatment. This cellular protein RTN3 can act as the potential therapeutic target to treat the HIV infection as it is revealed to play an important role in a specific pathway critical in progression of Hepatitis C virus disease, results published in the journal PLOS One.
"By identifying the areas of the [RTN3] protein that lead to the formation of an infectious #exosome, we can now look for distinctive molecules that block the interaction with the #viralRNA.” – @inrsciences https://t.co/GYcTBalsDs
— Exosome RNA (@ExosomeRNA) October 23, 2020
Hepatitis C is a liver infection that can lead to acute or chronic liver damage caused by the hepatitis C virus., nearly affecting 3.9 million people in the U.S. Hepatitis is mostly asymptomatic where virus silently spreads through an infected person’s blood or body fluids.
This promising discovery has the potential to intervene better treatments for the disease, which yearly kills approximately 500,000 people. In case of acute hepatitis, people don’t lead to life-threatening illnesses, while, in case of chronic hepatitis deaths are reported.
According to WHO, in nearly 30% (15–45%) of infected persons, immune system spontaneously clear the virus within 6 months of infection without any treatment in acute cases, compared to chronic cases where the remaining 70% (55–85%) of persons will develop chronic HCV infection. The risk of cirrhosis ranges between 15 – 30% withing 20 years in chronic cases.
Normally, the immune system needs to recognize a virus to attack it and prevent infection. The Hepatitis C virus, however, is a master of disguise. It moves around, undetected, in exosomes, which are cell-released microvesicles vesicles that normally function in cellular communication, transport, and cellular waste disposal. This novel research revealed that the Hepatitis C viruses interact with a key area of the RTN3 protein utilizing it to insert their viral RNA into exosomes.
Researchers used a cell line that was infected with Hepatitis virus. Later a protein named RTN3 was found to overexpress in case of HIV infection. It was determined that HIV virus interacts with the RTN3 protein and enters a structure called exosome.
Identification of this protein therefore can help preventing the formation of an infectious exosome, which causes progression of the disease by interacting with the viral RNA. It was asserted that this RTN3 protein would help in preventing the viral RNA from being able to enter exosomes and hide it from the body’s immune system.
Moreover, it is hoped that it will open new options for more research on other viruses that use exosomes to evade the detection by immune system, such as, Zika, HIV, and Hepatitis B viruses also use exosomes to hide inside them to evade the immune system and cause infection. Under pathological conditions, this disguise prevent the vaccines to perform their optimal function even if antibodies are developed which results in an inability to prevent the infection.
“We are the first researchers to demonstrate the exosomal role that this protein plays in hepatitis C pathogenesis,” said Professor Terence Ndonyi Bukong.