Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599712
Title: Role of the 5'-leader in encapsidation of HIV-2 genomic RNA
Author: Griffin, S.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2001
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Abstract:
The focus of the research presented herein was to characterise the cis-acting RNA signals known as Ψ, that direct the encapsidation of Human Immunodeficiency Virus type 2 (HIV-2) genomic RNA, and to better understand the mechanisms of the process in order to develop gene delivery systems based on the virus. Deletion mutations in the context of the full-length molecular clone of HIV-2 ROD identified a region containing a major Ψ element located between the primer binding site and the major splice donor. Disruption of this sequence prevented efficient packaging of viral RNA in transient transfections of COS-1 cells without affecting viral protein production. Furthermore, viruses with this mutation were unable to spread following infection of Jurkat T-cell cultures. Previous work in the laboratory has shown that HIV-2 employs a co-translational mechanism to select its genome for encapsidation as Ψ is present on all viral transcripts. This would seemingly preclude HIV-2 from use in gene delivery systems. It was observed, however, that availability of the viral core polyprotein, Gag, was a limiting factor for the encapsidation process. Competition occurred for Gag made by Ψ-deficient viruses when they were co-transfected with RNAs that contained Ψ. This allowed efficient packaging of vector RNAs, showing that HIV-2 could in fact be used in gene delivery systems. Inclusion of sequences from the MA domain of gag in vectors further enhanced their encapsidation. The novel finding that Gag availability was limiting was then exploited to generate vector preparations potentially free of contamination by helper virus RNA, making HIV-2 an attractive gene delivery system in terms of bio-safety. The role of the 5'-leader in both encapsidation and the related process of RNA dimerisation was also investigated using in vitro assay systems.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.599712  DOI: Not available
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