A team of scientists at The Rockefeller University has produced for the first time an infectious form of the hepatitis C virus (HCV) in laboratory cultures of human cells. The finding, reported in the June 9 issue of Science Express, will allow scientists to study every stage of the HCV life cycle and develop drugs to treat this life-threatening disease that affects more than 170 million people around the world.
"The inability to reproduce aspects of the hepatitis C virus life cycle in cell culture has slowed research progress on this important human pathogen," says senior author Charles M. Rice, Ph.D., Maurice R. and Corinne P. Greenberg Professor and head of the Laboratory of Virology and Infectious Disease at Rockefeller.
"This system lays the foundation for future test tube studies of the virus life cycle and may help in the development of new drugs for combating HCV," adds Rice, who is the scientific director of the Center for the Study of Hepatitis C, a collaborative research and clinical effort of Rockefeller, Weill Medical College of Cornell University, and New York- Presbyterian Hospital
Like all viruses, HCV cannot replicate by itself; instead it takes over the machinery of a host cell to make copies of itself. Much about the life cycle of HCV remains poorly understood because scientists have been unable to reproduce an infectious form of HCV that they can observe in cell cultures. The method developed by Rice and his colleagues, including scientists at the Massachusetts Institute of Technology and the Scripps Research Institute, changes that.
"The hallmark of viruses is their ability to exist in a form outside the host cell capable of infecting new cells," says first author Brett Lindenbach, Ph.D., a postdoctoral fellow in Rice's lab. "Our method replicates and produces virus particles that can infect new cells, initiating replication in them and leading to the production of more virus particles."
Although little is know about the HCV life cycle, researchers think that in humans the virus enters a liver cell and delivers its RNA and proteins into the cell cytoplasm. HCV carries its genetic information in its RNA, which is separated from the protein, copied, and then joined with new protein components before being released from the liver cell to infect other cells.