TY  - JOUR
A1  - Djakovic, Lara
A1  - Hennig, Thomas
A1  - Reinisch, Katharina
A1  - Milić, Andrea
A1  - Whisnant, Adam W.
A1  - Wolf, Katharina
A1  - Weiß, Elena
A1  - Haas, Tobias
A1  - Grothey, Arnhild
A1  - Jürges, Christopher S.
A1  - Kluge, Michael
A1  - Wolf, Elmar
A1  - Erhard, Florian
A1  - Friedel, Caroline C.
A1  - Dölken, Lars
T1  - The HSV-1 ICP22 protein selectively impairs histone repositioning upon Pol II transcription downstream of genes
JF  - Nature Communications
N2  - Herpes simplex virus 1 (HSV-1) infection and stress responses disrupt transcription termination by RNA Polymerase II (Pol II). In HSV-1 infection, but not upon salt or heat stress, this is accompanied by a dramatic increase in chromatin accessibility downstream of genes. Here, we show that the HSV-1 immediate-early protein ICP22 is both necessary and sufficient to induce downstream open chromatin regions (dOCRs) when transcription termination is disrupted by the viral ICP27 protein. This is accompanied by a marked ICP22-dependent loss of histones downstream of affected genes consistent with impaired histone repositioning in the wake of Pol II. Efficient knock-down of the ICP22-interacting histone chaperone FACT is not sufficient to induce dOCRs in ΔICP22 infection but increases dOCR induction in wild-type HSV-1 infection. Interestingly, this is accompanied by a marked increase in chromatin accessibility within gene bodies. We propose a model in which allosteric changes in Pol II composition downstream of genes and ICP22-mediated interference with FACT activity explain the differential impairment of histone repositioning downstream of genes in the wake of Pol II in HSV-1 infection.
KW  - herpes virus
KW  - transcription
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-358161
VL  - 14
ER  - 
TY  - JOUR
A1  - Wallaschek, Nina
A1  - Reuter, Saskia
A1  - Silkenat, Sabrina
A1  - Wolf, Katharina
A1  - Niklas, Carolin
A1  - Özge, Kayisoglu
A1  - Aguilar, Carmen
A1  - Wiegering, Armin
A1  - Germer, Christoph-Thomas
A1  - Kircher, Stefan
A1  - Rosenwald, Andreas
A1  - Shannon-Lowe, Claire
A1  - Bartfeld, Sina
T1  - Ephrin receptor A2, the epithelial receptor for Epstein-Barr virus entry, is not available for efficient infection in human gastric organoids
JF  - PLoS Pathogens
N2  - Epstein-Barr virus (EBV) is best known for infection of B cells, in which it usually establishes an asymptomatic lifelong infection, but is also associated with the development of multiple B cell lymphomas. EBV also infects epithelial cells and is associated with all cases of undifferentiated nasopharyngeal carcinoma (NPC). EBV is etiologically linked with at least 8% of gastric cancer (EBVaGC) that comprises a genetically and epigenetically distinct subset of GC. Although we have a very good understanding of B cell entry and lymphomagenesis, the sequence of events leading to EBVaGC remains poorly understood. Recently, ephrin receptor A2 (EPHA2) was proposed as the epithelial cell receptor on human cancer cell lines. Although we confirm some of these results, we demonstrate that EBV does not infect healthy adult stem cell-derived gastric organoids. In matched pairs of normal and cancer-derived organoids from the same patient, EBV only reproducibly infected the cancer organoids. While there was no clear pattern of differential expression between normal and cancer organoids for EPHA2 at the RNA and protein level, the subcellular location of the protein differed markedly. Confocal microscopy showed EPHA2 localization at the cell-cell junctions in primary cells, but not in cancer cell lines. Furthermore, histologic analysis of patient tissue revealed the absence of EBV in healthy epithelium and presence of EBV in epithelial cells from inflamed tissue. These data suggest that the EPHA2 receptor is not accessible to EBV on healthy gastric epithelial cells with intact cell-cell contacts, but either this or another, yet to be identified receptor may become accessible following cellular changes induced by inflammation or transformation, rendering changes in the cellular architecture an essential prerequisite to EBV infection.
KW  - Organoids
KW  - ephitelial cells
KW  - gastrointestinal infections
KW  - cancers and neoplasms
KW  - Epstein-Barr virus
KW  - flow cytometry
KW  - epithelium
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259206
VL  - 17
IS  - 2
ER  -