Animal Models for Hepatitis C Infection Studies

Hepatitis C virus (HCV) infection is among the main causes of cirrhosis and hepatocellular carcinoma all over the world. Despite common use of direct acting antiviral agents, treatment in chronic HCV hepatitis remains inadequate; and HCV is responsible for more than 300,000 deaths annually due to hepatic reasons. Currently, there is not a vaccine available to prevent HCV infection. Since its discovery, our knowledge about HCV has grown substantially with the help of animal studies. Development of appropriate animal models has great importance for research on HCV and for development of vaccine and medications. Limitations in studies on HCV are mostly because appropriate animal models cannot be found due to restraints arising from selective sensitivity of HCV between humans and primates. Chimpanzees are the best models for studies on innate or acquired host immune responses and HCV infection. The chimpanzee model has played an important role both prior to and after the discovery of HCV, as the etiological agent of non-A, non-B hepatitis (NANBH). Chimpanzees have been irreplaceable for proving NANBH is an infectious disease caused by a separate agent; furthermore they provided great benefits as an in vivo system for identification trials and for obtainment of sufficient material to be used in biological amplification of the virus. Large amounts of plasma have been obtained from chimpanzees for molecular cloning of HCV genome. Recently, the focal point of the studies have been the animal modification for the purpose of letting the HCV entry, replication and infectivity. In this study, we have discussed the proper animal models, in which there are chimpanzees, tupaia, mouse and rats for HCV studies. In addition to this, we have also aimed to investigate the advantages and disadvantages of each model in the model design process. Studies on animal models have critical significance in that they cast light on the full comprehension of the HCV infection, and form the foundations of future treatments and possible prevention measures.