<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Virus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses?"^^ . "Changes in viral host cell tropism by e.g. changing receptor usage can lead to altered\r\ndisease manifestations, requiring different treatment modalities. Hepatitis Delta virus\r\n(HDV), a small hepatotropic RNA virus, is known to depend on hepatitis B virus (HBV)\r\nenvelope proteins for envelopment and spread. However, as HDV possesses the ability\r\nto replicate in non-hepatic cells and since envelopment of HDV was recently proposed to\r\nbe mediated by non-HBV viruses, there might be an increased potential for altered host\r\ncell tropism of HDV due to differential envelope protein usage. This would have major\r\nclinical implications, as currently only HBV positive carriers are screened for HDV and\r\nspecific therapeutic options only target HBV-dependent spread.\r\nViruses that were proposed to mediate envelopment of HDV include hepatitis C virus\r\n(HCV) and vesicular stomatitis virus (VSV). As HDV is known for its liver tropism, I\r\nfocused primarily on hepatitis C virus (HCV) as potential HBV-independent helper and\r\naimed to evaluate the following questions: a) Does HDV make use of HCV envelope proteins? b) Can HDV be rendered susceptible for alternative helper usage by modification\r\nof HBV specificity determinants in HDV? c) What is the zoonotic potential of HDV via\r\nutilisation of non-human hepadnaviral helper viruses?\r\nI made use of different human cell culture systems based on RNA transfection or viral\r\ninfection. Thereby, I was able to show efficient co-replication and co-infection of HDV\r\nand HCV in the same cell. However, production of HCV enveloped HDV particles was\r\nnot observed. Based on plasmid transfection, I showed that HDV preferentially uses\r\nHBV with little, if any, envelopment by HCV or VSV. Based on sequence comparison\r\nto an animal Delta-like agent putatively using HBV-independent spread, I hypothesised\r\nthat determinants specifically targeting the HBV envelope might hinder HDV from using alternative viral envelopes. However, eliminating HBV specificity determinants from\r\nHDV did not render HDV competent to use non-HBV envelopes. As the HDV-HBV\r\ninteraction is mediated by a tryptophan-rich domain on HBV envelope proteins, I examined HCV and VSV envelope proteins for the presence of similar determinants. However,\r\nalgorithm-based protein structure prediction did not detect such determinants, which is\r\nconsistent with the almost exclusive envelopment of HDV by HBV. Last, I investigated\r\nvarious non-human hepadnaviruses for their capacity to provide helper function for HDV.\r\nTo this end, I produced non-infectious self-assembling particles exclusively consisting of\r\nenvelope proteins and preliminarily investigated secretion of HDV RNA mediated by\r\nthese particles.\r\nTaken together, the data presented in this study support the current view that HDV\r\nmost likely utilises exclusively HBV as helper virus, further arguing for co-evolution of\r\nthese two viruses."^^ . "2024" . . . . . . . "Anna-Clara"^^ . "Schnell"^^ . "Anna-Clara Schnell"^^ . . . . . . "Virus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses? (PDF)"^^ . . . "PhDThesisSchnell.pdf"^^ . . . "Virus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses? (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Virus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses? (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Virus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses? (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Virus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses? (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Virus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses? (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #34251 \n\nVirus Venetian Masked Ball: Does the Hepatitis Delta Virus Use Different Helper Viruses?\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .