Ilaria Gasperini

Parvovirus B19 (B19V) is a human ssDNA virus with ample pathogenic potential, characterized by a selective tropism for erythroid progenitor cells (EPCs) in the bone marrow. In vitro, in addition to EPCs, UT7/EpoS1 cells are widely used as a model cell system, permissive to viral replication, although in a restrictive pattern. In our work, we applied mRNA high-throughput sequencing technology (HTS) and a dedicated bioinformatic pipeline to investigate both viral and cellular expression profiles in the course of B19V infection of UT7/EpoS1 cells. Mapping of the viral transcriptome detailed the differential expression pattern across early and late time points in the course of infection, at 2, 16 and 48 h post-infection (hpi). Analysis of the cellular transcriptome indicated that downregulation of genes involved in the immune/cytokine/interleukin response was prominent from earlier time points throughout the time course of infection. Upregulation of genes involved in cell stress response was found at 2 hpi, and genes involved in cell cycle regulation were affected mainly at 16 hpi and 48 hpi. A comparative analysis was performed with EPCs, showing similarity in their viral expression profile but substantial divergence in the virus-induced dysregulation of the cellular transcription pattern. This dual-transcriptome analysis of infected UT7/EpoS1 cells and comparison with EPCs provides groundwork for future research aimed at providing a better definition of the pathogenic mechanisms of B19V.

Parvovirus B19 (B19V) is a human ssDNA virus with an ample pathogenic potential, characterized by a selective tropism for erythroid progenitor cells (EPC) in the bone marrow. In vitro, in addition to EPCs, UT7/EpoS1 cells are widely used as a model cells system, permissive to viral replication although in a restrictive pattern. In our work, we applied mRNA high throughput sequencing technology (HTS) and a dedicated bioinformatic pipeline to investigate both viral and cellular expression profile in a course of B19V infection of UT7/EpoS1 cells. Mapping of the viral transcriptome detailed the differential expression pattern across early and late time points in the course of infection, at 2, 16 and 48 hours post-infection (hpi). Analysis of cellular transcriptome indicated that downregulation of genes involved in the immune/cytokine/interleukin response was prominent from earlier times through the whole time course of infection. Upregulation of genes involved in cell stress response was found at 2 hpi, and genes involved in cell cycle regulation were involved mainly at 16 hpi and 48 hpi. A comparative analysis was performed to EPCs, showing similarity in the viral expression profile, but substantial divergence in the virus-induced dysregulation of the cellular transcription pattern. This dual transcriptome analysis on infected UT7/EpoS1 cells and comparison to EPCs provide ground for future research aimed at a better definition of the pathogenic mechanisms of B19V.

Parvovirus B19 (B19V) is a human ssDNA virus with ample pathogenic potential. It is characterized by a selective tropism for erythroid progenitor cells (EPC), exerting a cytotoxic effect with blockade of erythropoiesis. In our work, we investigated both viral and cellular expression profile in the course of infection of EPCs cultures via mRNA high throughput sequencing technology (HTS) and a dedicated bioinformatic pipeline, reconstructing both the viral and cellular transcriptome and their variations. A productive infection was confirmed as restricted to EPCs expressing mature differentiation markers and the specific receptor for virus VP1u region. mRNA HTS reconstructed the viral transcriptome in terms of localization and abundance of the different mRNA species, detailing the differential expression profile of B19V among early or late times in the course of infection. Analysis of cellular transcriptome indicated that variation was mainly driven by the cellular differentiation process, with the virus impacting to a lesser level, but still clearly separating infected vs. non-infected profiles. At early times post-infection, variations were typical of cellular sensing of viral infection and aimed at the induction of an antiviral state. At later times in the course of infection, the cellular population showed induction of an inflammatory response, related to TNF and IL-10, and a transition to adaptive immunity with evidence of upregulation of genes involved in MHC-II presentation. This dual-transcriptome analysis on infected EPCs population can lay the ground for future research aimed at a better definition of the pathogenetic mechanisms of B19V.