Evaluation of novel in vitro models for human sapovirus infection

Magdalena Neijd, Linköping University, Sweden

Magdalena Neijd, Division of Molecular Medicine and Virology, Linköping University, Sweden Johan Nordgren, Division of Molecular Medicine and Virology, Linköping University, Sweden Berit Hammas, Department of Clinical Microbiology, Karolinska University Hospital, Sweden Jan Albert, Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Sweden and Department of Medicine, Karolinska Institute, Sweden Lennart Svensson, Division of Molecular Medicine and Virology, Linköping University, Sweden Marie Hagbom, Division of Molecular Medicine and Virology, Linköping University, Sweden

Entry and Replication

Human sapovirus is increasingly recognized as a significant cause of acute viral gastroenteritis, but in vitro studies have been limited due to the previous lack of suitable cell models. In this study, we established two novel in vitro models for sapovirus infection: the human enteroendocrine cell (EEC) line GOT1 and apical-out 3D human enteroids. Using 31 sapovirus-positive fecal samples, we compared these models with the EEC-derived HuTu80 cell line and enteroid monolayers. Among the analyzed samples, genotypes GI.1 (36%), GII.1 (32%), and GII.3 (26%) were identified, with GI.1 exhibiting the highest fecal viral load. We demonstrate that, in addition to HuTu80 cell line, sapovirus can also replicate in GOT1. GOT1 supported replication of a higher percentage of GI.1 samples (82%) compared to HuTu80 (70%) and with a generally greater replication efficiency. Moreover, unlike HuTu80, GOT1 was able to support the replication of GII.1 and GII.3 genotypes. Given that organoids are considered a more physiologically relevant model than transformed cell lines, we developed a robust sapovirus infection model using apical-out 3D enteroids. Compared to enteroid monolayers, the apical-out model supported replication of a higher number of GI.1 samples and with higher replication efficiency. In conclusion, these findings provide valuable insights for future in vitro studies of sapovirus infection and replication, which may contribute to a better understanding of sapovirus cell tropism and pathogenesis.