Researchers have identified the role of a protein involved in the progression of hepatitis C virus (HCV) infection that has demonstrated a potential new avenue for treatment, according to a study published in PLOS ONE.

Currently, there is no vaccine for HCV infection, which affects more than 130 million people worldwide. There are antivirals available, but these are expensive and less accessible to developing countries in which there is the greatest need for such treatments.

Researchers at the Institut national de la recherche scientifique (INRS) in Quebec City observed that the cellular protein reticulon-3 (RTN3) was involved in the mediation of an essential pathway for HCV development and progression. This discovery has the potential to shine a light upon new avenues for improved treatments for this disease, which kills approximately 500,000 people annually.

HCV works by hindering the immune system’s ability to recognize the virus’ presence, allowing it to remain within the body undetected. The virus then inserts viral ribonucleic acid (RNA) into exosomes, which are membrane-bound extracellular vesicles that support cellular communication, transport, and cellular waste disposal.

The new research conducted at INRS found that additionally, the HCV interacts with a part of the RTN3 protein in order to make this insertion of viral RNA into exosomes.

"We are the first researchers to demonstrate the exosomal role that this protein plays in hepatitis C pathogenesis," said lead author Terence N. Bukong, PhD, a professor of virology and hepatology at INRS, in a press release. "By identifying the areas of the protein that lead to the formation of an infectious exosome, we can now look for distinctive molecules that block the interaction with the viral RNA."

Bukong explained further that such distinctive molecules could prevent viral RNA from entering exosomes and block the HCV ability to obstruct its detection by the immune system.

Additionally, this discovery may lead to further avenues for treatment of other viruses that use exosomes to evade detection, Bukong noted.

"For example, studies have shown that HIV, Zika, and Hepatitis B viruses also hide inside exosomes. This disguise creates a problem for the optimal function of vaccines because even if antibodies are developed, they are unable to block viral infection or transmission," Bukong said in the press release. "If the RTN3 protein also plays an important role in these other illnesses, it could help us make more effective treatments, and, potentially, more effective vaccines."

REFERENCE
A promising discovery could lead to better treatment for Hepatitis C. Quebec City: Institut national de la recherche scientifique; October 22, 2020. https://www.eurekalert.org/pub_releases/2020-10/indl-apd102120.php. Accessed October 26, 2020.