Biology subjects

Oberstein, A.

Publications and source records attributed to Oberstein, A..

3 recordsLinked to original sources

bioRxiv2024

The Epithelial-to-Mesenchymal Transition Supports HCMV Infection and Biosynthesis in Mammary Epithelial Cells Through Two Distinct Mechanisms.

Human cytomegalovirus (HCMV) infects a wide range of cell types in the body, including a variety of epithelial cell types. Despite the significance of epithelial cells during infection, HCMV has been difficult to study in epithelial cells. In this study, we examined HCMV infection in mammary and prostate epithelial cell lines, finding that the virus establishes a semi-permissive, biosynthetically abortive state. Building on previous work, we hypothesized that shifting epithelial cells to a mesenchymal cell state would restore HCMV biosynthesis and progeny production. To test this hypothesis, we induced epithelial-to-mesenchymal transition (EMT) using TGF-{beta} and the EMT-transcription factor (EMT-TF) SNAIL. We found that shifting strongly epithelial cell lines to a mesenchymal cell state shifted HCMV infection from a semi-permissive to fully permissive state. This effect appeared to involve two distinct mechanisms: EMT-sensitive enhancement of viral entry and EMT-sensitive enhancement of viral mRNA translation. Although the precise mechanisms remain elusive, our findings identify the epithelial-mesenchymal cell state axis as an important regulator of HCMV infection and provide new insights into how cellular differentiation states influence viral replication. They also raise the possibility that the EMT pathway, a fundamental pathway involved in development and cancer metastasis, could regulate HCMV infection in-vivo, potentially contributing to viral persistence or pathogenesis in epithelial tissues.

microbiology↗

bioRxiv2024

ARPE-19 Epithelial Cells Fail To Initiate Type-I Interferon Signaling in Response to Human Cytomegalovirus Infection.

ARPE-19 cells are a commonly used epithelial model for studying human cytomegalovirus (HCMV) infection. We recently found that ARPE-19 cells assume a mesenchymal phenotype when maintained at low confluency and that ARPE-19 cells resemble mesenchymal fibroblasts rather than epithelial cells in HCMV infection assays. Here, using comparative proteomics analysis, we find that subconfluent ARPE-19 cells are also deficient in their ability to initiate canonical type-I interferon signaling. Comparative proteomic analysis between subconfluent ARPE-19 and MRC-5 cells revealed a lack of canonical type-I interferon response in ARPE-19 cells upon HCMV infection, evidenced by the absence of interferon stimulated gene (ISG) induction. qRT-PCR and RNA-sequencing analysis revealed that ARPE-19 cells fail to initiate interferon-beta transcription in response to HCMV infection, yet they are competent to respond to exogenously interferon-b, indicating a failure in early pathogen detection. ARPE-19 cells showed low baseline levels of key intracellular pattern recognition receptors (PRRs) such as CGAS and IFI16, as well as the signaling molecule STING. This deficiency was associated with a failure to activate IRF3 phosphorylation, a crucial step in interferon signaling. These findings suggest an upstream defect in the early detection of viral components, likely due to reduced expression of critical PRRs. ARPE-19 cells may be inherently deficient in initiating interferon responses due to their derivation or possibly due to their origin from an immune-privileged tissue. Our results continue to highlight important phenotypic characteristics of the ARPE-19 cell line; important considerations for those using ARPE-19 cells as an experimental infection model for studying HCMV or other human viruses.

microbiology↗

bioRxiv2023

ARPE-19 Retinal Pigment Epithelial Cells Cultured under Subconfluent Conditions Display Mesenchymal Cell State Characteristics that Correlate with Permissivity to HCMV Infection.

Human cytomegalovirus (HCMV) has a broad cellular tropism and epithelial cells are important physiological targets during infection. The retinal pigment epithelial cell line ARPE-19 has been used to model HCMV infection in epithelial cells for decades and remains a commonly used cell-type for studying viral entry, replication, and the cellular response to infection. We previously found that ARPE-19 cells, despite being derived from an epithelial cell explant, express extremely low levels of canonical epithelial proteins, such as E-cadherin and EpCAM. Here, we perform comparative studies of ARPE-19 and additional epithelial cell lines with strong epithelial characteristics. We find that ARPE-19 cells cultured under subconfluent conditions resemble mesenchymal fibroblasts, rather than epithelial cells; consistent with previous studies showing that ARPE-19 cultures require extended periods of high confluency culture to maintain epithelial characteristics. By reanalyzing public gene expression data and using machine-learning, we find evidence that ARPE-19 cultures maintained across many labs exhibit mesenchymal characteristics and that the majority of studies employing ARPE-19 use them in a mesenchymal state. Lastly, by performing experimental HCMV infections across mesenchymal and epithelial cell lines, we find that ARPE-19 cells behave like mesenchymal fibroblasts, producing logarithmic yields of cell-free infectious progeny, while cell lines with strong epithelial character exhibit an atypical infectious cycle and naturally restrict the production of cell-free progeny. Our work highlights important characteristics of the ARPE-19 cell line and suggests that sub-confluent ARPE-19 cells may not be optimal for modeling epithelial infection with HCMV or other human viruses. It also suggests that HCMV biosynthesis and/or spread may occur quite differently in epithelial cells compared to mesenchymal cells. These differences could contribute to viral persistence or pathogenesis in epithelial tissues.

cell biology↗