Description of Research Expertise

Research Interests
Human hepatitis delta virus (HDV) is an infectious agent found in nature only in association with hepatitis B virus (HBV). In fact, HDV is less than a virus in that it needs help from HBV to carry out a cycle of replication. Our efforts are directed towards understanding the structure and replication of HDV, and the nature of its interactions with HBV.

Key words: hepatitis delta, RNA transcription, RNA processing, miRNA, virus attachment and entry.

Description of Research
HDV research offers several unique and tantalizing problems in cell and molecular biology. The prime example is that the RNA genome is able to redirect a host polymerase to the HDV RNA template.

Rotation Projects for 2005-2006
Currently there are two main research areas in this lab. Both are concerned hepatitis delta virus (HDV), a subviral agent that replicates using the envelope proteins of hepatitis B virus (HBV) as a helper virus.

The first area addresses how the small circular RNA genome of HDV can be copied by redirection of the host RNA polymerase II. This seemingly unique situation has wider implications in that we are trying to understand how RNA molecules either act as templates or are inhibited from acting as templates for host RNA polymerases.

The second area concerns how HDV is assembled into virus particles and how these infect primary human hepatocytes, the normal and restricted host cell for this virus. The wider significance of these studies is that we are at the same time obtaining information that also applies to HBV. That is, we are determining how HBV is able to attach to and infect susceptible cells. This is a major unsolved question for what is the major cause worldwide of chronic liver disease and hepatocellular carcinoma.

Lab personnel:
John Taylor - Senior Member (Fox Chase Cancer Center) and Adjunct Assoc. Prof. (U. of Penn)
Jinhong Chang - Staff Scientist
Severin Gudima - Research Associate
Ning Chai - Postdoctoral Fellow