title: Analyzing the role of a cellular mechanism in HIV infection and Evaluation of novel antiviral compounds
creator: Münter, Sylvia Gabriele
subject: ddc-540
subject: 540 Chemistry and allied sciences
description: The human immunodeficiency virus (HIV) is the causative agent of the acquired immunodeficiency syndrome (AIDS). Despite more than twenty years of intense research still no vaccine or curing therapy has been found. For the development of novel antiviral compounds, understanding of the HIV lifecycle as well as the molecular mechanisms of host pathogen interactions are a prerequisite. Like all viruses, HIV subcontracts cellular machineries for efficient replication and production of new progeny. A particular feature of lentiviruses is the active transport of the pre-integration complex (PIC) into the nucleus. The mechanism remains elusive, yet in the case of HIV the viral protein R (Vpr), a small 14kDa accessory protein, is one candidate possibly implicated in the process. The protein stays associated to the PIC until nuclear translocation. Furthermore it has been shown, that Vpr binds to the nuclear pore complex (NPC). This interaction might therefore be the link mediating nuclear import of the PIC. Moreover the cytoskeleton has been shown to play a major role in cytoplasmic transport of viral particles. In this context, we observed the nuclear envelope (NE) to be embedded in a perinuclear actin shell and displaying highly dynamic nuclear invaginations. We developed a novel approach to visualize actin inside living cells based on a fluorescent analog of cytochalasin D (CD-BODIPY). Due to specific binding to free-barbed-ends of short actin fibers, we could show that this compound visualizes a high turnover actin pool around the NE and inside NE-membrane invaginations of living cells. Although reported in many different cell types, the possible role of perinuclear actin filaments in the dynamic structural plasticity of the NE remains unresolved. We could show that NE-membranes alone are sufficient to nucleate polymerizing actin filaments in vitro, involving both actin recruitment to their surface, and filament growth. Accordingly, our results demonstrate that perinuclear actin dynamics are orchestrated by the NE itself. Therefore, by binding of Vpr to the NPC, the virus could possibly exploit this pool of polymerizing actin as a new strategy to overcome the nuclear membrane. Furthermore, we tested peptide nucleic acids (PNAs) as new compounds to inhibit viral spread at different stages of the lifecycle. PNAs have been developed recently and dispose of several features to be a powerful tool for a novel antisense approach. We synthesized a series of PNAs directed against crucial sequences in the HIV genome and tested them under various conditions. This showed in particular, that infectivity of virions produced in the presence of PNAs was significantly diminished. In another viral system, PNAs targeted against the borna disease virus (BDV), could provide evidence for the requirement of the surface glycoprotein (GP) in BDV infection. Moreover, the treatment could effectively inhibit viral spread in primary neurons. These results demonstrate PNAs to be a powerful molecular tool and a potential antiviral drug candidate.
date: 2004
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/4796/1/PhD_smuenter.pdf
identifier: DOI:10.11588/heidok.00004796
identifier: urn:nbn:de:bsz:16-opus-47969
identifier:   Münter, Sylvia Gabriele  (2004) Analyzing the role of a cellular mechanism in HIV infection and Evaluation of novel antiviral compounds.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/4796/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng