Faculty Summaries
William S Mason, PhD
William S Mason, PhD
Professor Emeritus
Office Phone: 215-728-2462
Office: R205
Hepatitis B Viruses and Liver Cancer

Hepatitis B virus (HBV) chronically infects hepatocytes, the major parenchymal cell of the liver. Hepatocytes represent a long-lived, self-replenishing population in the healthy liver. If the immune system fails to clear the infection within a few months, individuals usually remain infected for life. Chronic infections lead to chronic liver injury, cirrhosis and hepatocellular carcinoma (HCC). The primary cause of these diseases is the injury caused by the antiviral immune response to infected hepatocytes, as infection per se does not appear to be cytotoxic. The goal of ongoing research is to test the hypothesis that chronic immune killing of infected hepatocytes selects for clonal expansion of hepatocytes that have lost the ability to support HBV replication. Clonal hepatocyte repopulation of the liver is an HCC risk factor.

Description of research projects
Selected Publications

Fox Chase Programs

  1. Seeger C, Mason WS. Sodium-dependent taurocholic cotransporting polypeptide: a candidate receptor for human hepatitis B virus. Gut. 2013;62:1093-95. PubMed
  2. Zoulim F, Mason WS. Reasons to consider earlier treatment of chronic HBV infections. Gut. 2012;61:333-6. PubMed
  3. Reaiche GY, Le Mire MF, Mason WS, Jilbert AR. The persistence in the liver of residual duck hepatitis B virus covalently closed circular DNA is not dependent upon new viral DNA synthesis. Virology. 2010;406:286-92. PubMed
  4. Mason WS, Liu C, Aldrich CE, Litwin S, Yeh MM. Clonal expansion of normal appearing hepatocytes during chronic HBV infection. J Virol. 2010;84:8308-15. PubMed
  5. Mason WS, Low H-C, Xu C, Aldrich CE, Scougall CA, Grosse A, Clouston A, Chavez D, Litwin S, Peri S, Jilbert AR, Lanford RE. Detection of clonally expanded hepatocytes in chimpanzees with chronic hepatitis B virus infection. J Virol. 2009;83:8396-8408. PubMed
  6. Mason WS, Xu C, Low H-C, Saputelli R, Aldrich CE, Scougall C, Grosse A, Colonno R, Litwin S, Jilbert AR. The amount of hepatocyte turnover that occurs during resolution of a transient hepadnavirus infection is reduced if virus replication is inhibited with entecavir. J Virol. 2009;82:1778-89. PubMed
  7. Mason WS, Litwin S, Jilbert AR. Immune selection during chronic hepadnavirus infection. Hepatol Int. 2008;2:3-16. PubMed
  8. Xu C, Yamamoto Y, Zhou T, Aldrich CE, Frank K, Cullen JM, Jilbert AR, Mason WS. The liver of woodchucks chronically infected with the woodchuck hepatitis virus contains foci of virus core antigen-negative hepatocytes with both altered and normal morphology. Virology. 2007;359:283-94. PubMed
All publications