Molecular Biology and Pathogenesis of Porcine Viral Infections

The research of our group at the IVI in Mittelhäusern is dedicated to porcine virology, in particular to the study of the molecular biology and pathogenesis of classical swine fever virus (CSFV) and porcine reproductive and respiratory syndrome virus (PRRSV) infections in the natural host. We are also expanding our research to African swine fever virus (ASFV) following the recent re-emergence of the virus in Europe. CSFV, ASFV and PRRSV cause important economic losses in the pig production worldwide. While CSFV has been eradicated from Europe recently, the virus is still present in Asia and Central America. PRRSV is endemic in the USA, in Asia and in most European countries except Switzerland. ASFV circulates in wild boar in Eastern Europe, causing sporadic outbreaks with high mortality rates in domestic pigs.

Over the past decade, our laboratory has established robust functional cDNA clones for relevant field isolates of CSFV and PRRSV. With these molecular tools at hand, we are applying reverse genetic approaches to characterize viral gene functions and viral virulence determinants in vitro, ex vivo and ultimately in vivo (Leifer et al., 2013; Rappe et al., 2016). In close cooperation with the group of Artur Summerfield, we are also studying the molecular mechanisms involved in the immunopathogenesis of CSFV and PRRSV infections. We are particularly interested in host factors interfering with or required for virus replication. Currently, we are studying the functions of different cellular factors we found to be dysregulated following CSFV infection of porcine macrophages. With the group of Volker Thiel, we are investigating double-membrane vesicle formation during PRRSV replication.

Based on our CSFV cDNA clone, we have developed a generic replicon platform for vaccine applications (McCullough et al., 2014). Using our standard vector backbone, we are also establishing functional cDNA clones for Japanese encephalitis virus (JEV) in order to study the viral determinants of JEV transmission and adaptation in pigs, in collaboration with the group of Artur Summerfield.