Hepatitis C virus (HCV) is a positive-strand RNA virus that infects over 170 million people worldwide. Multiple studies have demonstrated the adverse effects of human immunodeficiency virus (HIV) co-infection on liver fibrosis, HCV RNA levels, HCV disease progression, and response rates to HCV treatment. The mechanisms by which these two viruses interact remain unclear, as no direct virus-virus interactions have been demonstrated to date.
Because of the inability to infect small animals with HCV and the lack of efficient cell culture models, much of the current understanding of HCV pathogenesis has been inferred from studies of infected human samples. Using a variety of cell culture, immunologic, and molecular virology techniques, as well as patient-derived samples, we are investigating the pathogenic and evolutionary mechanisms by which viruses interact with the host and cause disease.
Current work in the laboratory involves studies of several hepatitis viruses, including hepatitis B (HBV), hepatitis E (HEV), and hepatitis G (HGV/GBV-C), as well as HIV. Ongoing research projects include: 1) characterizing the extent of extrahepatic replication of HCV and development of models of HCV replication; 2) HIV replication in hepatocytes and the development of novel in vitro systems of HIV/HCV co-infection; 3) genotypic and phenotypic characterization of hepatitis viruses, particularly in the context of HIV co-infection.
Blackard JT and KE Sherman. 2008. HCV/HIV co-infection: time to re-evaluate the role of HIV in the liver? Journal of Viral Hepatitis 15(5):323-330.
Blackard JT, Hiasa Y, Smeaton L, Jamieson DJ, Rodriguez I, Mayer KH, and Chung RT. 2007. Compartmentalization of hepatitis C virus (HCV) during HCV/HIV co-infection. Journal of Infectious Diseases 195(12):1763-1773.
Shire NJ, Rouster SD, Stanford SD, Blackard JT, Martin CM, Fichtenbaum CJ, and Sherman KE. 2007. The prevalence and significance of occult hepatitis B virus in a prospective cohort of HIV-infected patients. Journal of Acquired Immune Deficiency Syndromes. 44(3):309-314.
Martin CM, Welge JA, Shire NJ, Rouster SD, Shata MT, Sherman KE, and Blackard JT. 2009. Genomic variability associated with the presence of occult hepatitis B virus in HIV co-infected patients. Journal of Viral Hepatitis 17(8)588-597.
Schwarze-Zander C, Blackard JT, Zheng H, Addo MM, Lin W, Robbins GK, Sherman KE, Zdunek D, Hess G, and Chung RT. 2006. GB virus C (GBV-C) infection in hepatitis C virus (HCV)/HIV-coinfected patients receiving HCV treatment: importance of the GBV-C genotype. Journal of Infectious Diseases. 194(4):410-419.
Blackard JT, Kemmer N, and Sherman KE. 2006. Extrahepatic replication of HCV: insights into clinical manifestations and biological consequences. Hepatology 44(1):15-22.
Blackard JT, Smeaton L, Hiasa Y, Horiike N, Onji M, Jamieson DJ, Rodriguez I, Mayer KH, and Chung RT. 2005. Detection of hepatitis C virus (HCV) in serum and peripheral blood mononuclear cells of HCV mono-infected and HIV/HCV co-infected persons. Journal of Infectious Diseases (192)2:258-265.
Blackard JT, Rouster SD, Nady S, Galal G, Marzuuk N, Rafaat MM, Daef E, Seif El Din S, Purcell RH, Emerson SU, Sherman KE, and Shata MT. 2009. Genotypic characterization of symptomatic hepatitis E virus (HEV) infections in Egypt. Journal of Clinical Virology 46(2):140-144.