The RNA Replication Site of Tula Orthohantavirus Resides within a Remodelled Golgi Network.

Katherine A Davies,John N Barr,Roger Hewson,Juan Fontana,Benjamin Chadwick,Jamel Mankouri

doi:10.3390/cells9071569

Abstract

The family Hantaviridae within the Bunyavirales order comprises tri-segmented negative sense RNA viruses, many of which are rodent-borne emerging pathogens associated with fatal human disease. In contrast, hantavirus infection of corresponding rodent hosts results in inapparent or latent infections, which can be recapitulated in cultured cells that become persistently infected. In this study, we used Tula virus (TULV) to investigate the location of hantavirus replication during early, peak and persistent phases of infection, over a 30-day time course. Using immunofluorescent (IF) microscopy, we showed that the TULV nucleocapsid protein (NP) is distributed within both punctate and filamentous structures, with the latter increasing in size as the infection progresses. Transmission electron microscopy of TULV-infected cell sections revealed these filamentous structures comprised aligned clusters of filament bundles. The filamentous NP-associated structures increasingly co-localized with the Golgi and with the stress granule marker TIA-1 over the infection time course, suggesting a redistribution of these cellular organelles. The analysis of the intracellular distribution of TULV RNAs using fluorescent in-situ hybridization revealed that both genomic and mRNAs co-localized with Golgi-associated filamentous compartments that were positive for TIA. These results show that TULV induces a dramatic reorganization of the intracellular environment, including the establishment of TULV RNA synthesis factories in re-modelled Golgi compartments.

Highlights

The genus Orthohantavirus, within the Hantaviridae family of the Bunyavirales order, comprises over 36 species of enveloped segmented negative stranded RNA viruses [1] that are found throughout the globe, with many capable of causing devastating human disease [2]
At this early time point, nucleocapsid protein (NP) compartments had an average area of 0.54 μm2 (14 cells and 1248 compartments analysed) with the largest structure within a single focal plane having an area of 11.8 μm2
After 7 dpi, the NP compartments had an average area of 0.96 μm2 (31 cells and 2959 compartments analysed) with the largest structure having an area of 154 μm2 (Figure 1A, middle row)

Summary

Introduction

The genus Orthohantavirus, within the Hantaviridae family of the Bunyavirales order, comprises over 36 species of enveloped segmented negative stranded RNA viruses [1] that are found throughout the globe, with many capable of causing devastating human disease [2]. Orthohantaviruses are mostly associated with a specific rodent host, in which they cause persistent infections [3]. Viruses of the OW clade, such as the Hantaan virus (HTNV) and the Seoul virus (SEOV), are associated with a haemorrhagic fever with renal syndrome (HFRS), whereas NW viruses including Andes virus (ANDV) and Sin Nombre virus (SNV) are the causative agents of hantavirus cardiopulmonary syndrome (HCPS). Both syndromes are characterised by extensive vascular leakage, with human mortality rates ranging from 0.1–10%

Methods

Results

Conclusion