Abstract Title
Human Norovirus Replicates in Hepatocytes and Other Liver Cells in Zebrafish Larvae
Presenter
Lorane Molineaux, KU Leuven
Co-Author(s)
Lorane Molineaux (1), Emma Roux (1), Jana Van Dycke (1), Joana Rocha-Pereira (1)
(1) KU Leuven - Department of Microbiology, Immunology and Transplantation, Rega Institute, Virus-Host Interactions & Therapeutic Approaches (VITA) Research Group, Leuven, Belgium
Abstract Category
Entry and Replication
Abstract
Human norovirus (HuNoV), the most common cause of viral gastro-enteritis, imposes a lethal threat to the immunocompromised, young and elderly population, with the manifestation of chronic infections that can last multiple years. Basic biological questions on HuNoV pathology have been elusive for many years due to the lack of appropriate in vivo models. We priorly established a novel, robust HuNoV replication model in zebrafish larvae and recently demonstrated that HuNoV GII.4 infection increases gut motility, thus causing disease-specific symptoms in this model.
There is growing evidence for the extraintestinal spread of HuNoV, exemplified by reports including neurological complications and importantly, viremia in children, immunocompromised adults and diverse animal models (infected with either mouse or HuNoV). Furthermore, a recent case of fatal, HuNoV-induced hepatitis, alongside non-fatal reported cases, accentuate the need to understand the extraintestinal spread of HuNoV to the liver. We previously showed that HuNoV VP1 was present in the zebrafish liver by immunohistological sections. Importantly, single-cell RNA sequencing (scRNA-seq) of HuNoV-infected larvae mapped the three HuNoV ORFs to hepatocytes. We now further investigated this by wholemount immunofluorescent confocal imaging and found both VP1 and dsRNA colocalized with hepatocytes in the transgenic line Tg(fabp10a:DsRed) (red fluorescent hepatocytes), proving active replication. Moreover, we are currently investigating the identity of other liver cells in which HuNoV replication is also taking place. Flow cytometry is being carried out to understand the relative importance of hepatocytes and other liver cell types in HuNoV infections. An additional round of scRNA-seq of dissected livers is ongoing.
There is growing evidence for the extraintestinal spread of HuNoV, exemplified by reports including neurological complications and importantly, viremia in children, immunocompromised adults and diverse animal models (infected with either mouse or HuNoV). Furthermore, a recent case of fatal, HuNoV-induced hepatitis, alongside non-fatal reported cases, accentuate the need to understand the extraintestinal spread of HuNoV to the liver. We previously showed that HuNoV VP1 was present in the zebrafish liver by immunohistological sections. Importantly, single-cell RNA sequencing (scRNA-seq) of HuNoV-infected larvae mapped the three HuNoV ORFs to hepatocytes. We now further investigated this by wholemount immunofluorescent confocal imaging and found both VP1 and dsRNA colocalized with hepatocytes in the transgenic line Tg(fabp10a:DsRed) (red fluorescent hepatocytes), proving active replication. Moreover, we are currently investigating the identity of other liver cells in which HuNoV replication is also taking place. Flow cytometry is being carried out to understand the relative importance of hepatocytes and other liver cell types in HuNoV infections. An additional round of scRNA-seq of dissected livers is ongoing.