Certain antibodies can keep hepatitis C from infecting new cells, paving the way for a treatment for stubborn infections and perhaps a vaccine to prevent them in the first place.
Research published Wednesday in Science Translational Medicine supports what scientists already suspected about the punch certain antibodies can deliver to hepatitis C.
Led by Dr. Ype P. de Jong, a gastroenterologist, professor, and attending physician at Cornell University, scientists showed that in cell cultures and in mice these broadly neutralizing antibodies interrupt the cycle of hepatitis C (HCV) infection.
“The largest takeaway is that HCV can rapidly be cured if the infectious cycle is interrupted,” de Jong told Healthline. “This goes against the current dogma that HCV is not [damaging] to the liver cells and happily replicates in the liver without killing either its host cell or being cleared by its host cell.”
Broadly neutralizing antibodies AR3A, AR3B, and AR4A bind to portions of cell envelopes and prevent the hepatitis C virus from entering. By interrupting the infectious cycle at the point when the virus enters cells, the virus is unable to continually infect new cells to keep a chronic infection going.
Chronic hepatitis C infections can cause no symptoms for decades. The
Although it often works slowly, hepatitis C destroys the liver. It may not be discovered until the disease is well established and a patient begins to show symptoms of liver failure, such as jaundice and fatigue.
New HCV drugs, such as sofosbuvir (Sovaldi), as well as others coming to market as early as this month, have changed the landscape of hepatitis C treatment. Once treated primarily with interferon and ribavirin, patients faced often brutal side effects, including vomiting and psychological problems. Sovaldi, in combination with other drugs, can now offer more than a 90 percent cure rate for some HCV genotypes.
However, some patients still cannot be cured. The high price of current medications is also driving the need for a vaccine. A 12-week course of Sovaldi alone costs $84,000.
Discoveries about these broadly neutralizing antibodies are helping to advance hepatitis C vaccine research. In a 2012 report published in Proceedings of the National Academy of Sciences, Professor Mansun Law at the Scripps Research Institute in California led a team that identified vulnerable spots on the virus’ cell envelope.
Finding such spots has been difficult because the hepatitis C virus mutates so quickly. Identifying these vulnerabilities is key to eventually meeting the urgent need for a vaccine. The World Health Organization
Some nations have been particularly hard hit by hepatitis C. In Egypt, one in five blood donors tests positive.
De Jong said their data is still preliminary. “It will be interesting if other genotypes can be cured in mice and if these observations are generalizable across genotypes,” he said.