Hepatitis C virus is transmitted by direct blood-to-blood contact: while blood transfusions were the main problem prior to 1990, transmission by blood products is no longer an issue in Germany - owing to highly sensitive tests. Nowadays, insufficient hygiene is the main hepatitis C virus infection risk. What can we do against the spread of this virus due to deficient hygiene? Prevention is the silver bullet for control of the hepatitis C virus. Another aspect in the focus of the members of the Virus Transmission research group: The envelope of the virus also plays a central role for infection of the host, the host's defence strategies and the production and release of new viruses.
Today, the transmission of hepatitis C virus occurs mainly via one of two ways: the use of injection equipment by unsterile technique in non-industrialised countries and drug abuse in the industrialised countries. Tattooing, piercing, acupuncture and medical interventions involving the use of insufficiently sterilised equipment can also lead to the transmission of hepatitis C virus (HCV). In contrast, HCV infections due to sexual intercourse with HCV-positive partners are rather rare. Transmission of an infection from an HCV-positive mother to her child, either before or after giving birth, occurs in up to four percent of the cases. It needs to be noted, though, that the route of virus transmission cannot be traced in approximately one third of all HCV patients.
An important aspect of the HCV issue is prevention, since it should be possible to control the transmission route from blood to blood using suitable hygiene measures. The researchers focus specifically on transmission in hospitals as well as the stability and sensitivity of HCV to chemical disinfectants. Since there are no suitable in-vitro models of HCV available, earlier investigations and the available experience are based mainly on studies of bovine diarrhoea virus (BVDV). This virus is closely related to HCV and techniques for culturing this virus have been available for some time. However, studies on this surrogate virus yield only fairly unreliable estimates about the infectiousness of HCV.
Significance of HCV envelope proteins for virus entry and the release of infectious viruses
Two proteins of the viral envelope are the main components of the viral coat with crucial significance for virus entry: the E1 and E2 proteins. They are responsible for binding to cellular receptors and then mediate the fusion of viral and cellular membranes. In addition, these proteins are the main target of virus-neutralising antibodies which presumably make a significant contribution to the control of infection, and they are essential for the production and release of infectious viruses. The researchers aim to better understand the role of these coat proteins in this context. They work with a cell culture model that has been developed only a few years ago and allows them to study these aspects. The members of the Virus Transmission research group analyse the role of HCV glycoproteins in viral morphogenesis. They investigate which steps of morphogenesis involve these coat proteins and how interactions amongst these the coat proteins and with other viral proteins contribute to the production of new viruses.