Researchers identify genes that allow animal hepatitis E virus strains to infect humans

Jul 16 2013

X.J. Meng, a University Distinguished Professor at Virginia Tech and a virologist at the Virginia-Maryland Regional College of Veterinary Medicine, has received a four-year, nearly $1.6 million grant from the National Institutes of Health to better understand the genetic elements that allow hepatitis E virus to transfer from animals to people.

Meng is the principal investigator in the new NIH award to identify the virus gene or genes that enable the animal hepatitis E virus strains in pigs and rabbits to infect humans. His laboratory in the Center for Molecular Medicine and Infectious Disease is one of the leading international research centers on hepatitis E virus, which causes an estimated 20 million liver infections each year.

"We are trying to pinpoint the genetic elements in the virus genome responsible for cross-species infection," Meng said. "If we can understand what viral gene or genes allow the virus to transfer from one animal species to another, then we can design better strategies to fight cross-species virus infection."

Researchers will not only look for the critical gene or genes that allow the virus to jump from one species to the next, but also will study the host immune factors that help defend against hepatitis E virus. The research team includes three co-investigators: Yaowei Huang, a research assistant professor; Dr. Tanya LeRoith, a clinical associate professor of anatomic pathology; and Scott Kenney, a senior research associate. All are in the college's Department of Biomedical Sciences and Pathobiology.

According to Meng, the majority of the world's emerging human viruses originate from animals — in other words, they are zoonotic. This means that studying all aspects of these zoonotic viruses, including their genome functions and host defense mechanisms, will helps scientists develop better preventive and control strategies to fight future infections.

Although the majority of hepatitis E virus infections occur in developing countries, sporadic and cluster cases of hepatitis E do occur in the United States and other industrialized countries. Less than 1 percent of infections prove fatal, but that number can reach as high as 28 percent in pregnant women who have contracted the virus. A vaccine against the hepatitis E virus recently became available in China, but has not been licensed in other countries yet.

Meng's laboratory has been studying this virus for decades and has received multiple NIH grants to study it. Earlier this year, Meng and his colleagues received a five-year, $2 million grant from the funding agency to study chronic hepatitis E virus infections in individuals with compromised immune systems.

During his time studying the virus, Meng's group has discovered two novel hepatitis E viruses: swine hepatitis E virus from pigs in 1997 and avian hepatitis E virus from chickens in 1999. Two years ago, one of his graduate students identified the first strains of the virus from rabbits in the United States. The laboratory will primarily use the swine and rabbit strains of the virus, as well as the human hepatitis E virus in this new NIH award to study the mechanism of cross-species infection.

Source: The Virginia-Maryland Regional College of Veterinary Medicine