Molecular Virology and Vectorology

  MEMBERSDr BEIGNON Anne-Sophie, SOUQUE Philippe, Dr ARHEL Nathalie, Dr COUTANT Frédéric, Dr MUNIER Sandie, Christelle LIARD

  Annual Report

The Molecular Virology and Vectorology group (VMV G5) conducts both basic and applied research projects. We study the early steps of HIV-1 replication with a particular emphasis on the mechanisms of intracellular routing and nuclear import of HIV-1 replication complexes. The understanding of some fundamental aspects of HIV-1 DNA nuclear import have brought about some important contributions in the lentiviral vector field in terms of vector design and gene transfer protocols in several cell types and tissues of major therapeutic interest. We also apply the lentiviral gene transfer technology to therapeutic gene transfer and vaccination, with a particular effort being channeled into the development of a therapeutic vaccination strategy against AIDS.

We showed that a three-stranded DNA structure, called the central DNA Flap, created during HIV-1 reverse transcription, acts as a cis-determinant of HIV-1 DNA nuclear import. This original mechanism contributed to the understanding of HIV-1 infection in non-dividing cells, a unique feature of lentiviruses among the retrovirus family. This finding also contributed to the optimization of lentiviral gene transfer vectors. Re-insertion of the DNA Flap sequence in lentiviral vectors complemented a strong nuclear import defect to wild-type levels and consequently stimulated gene transfer efficiency in all target cells and tissues examined so far, such as hematopoietic stem cells, hepatocytes, brain.... DNA Flap lentiviral vectors are now universally used in the numerous applications of lentiviral vector technology.

The VMV group is studying the early steps of HIV-1 replication using innovative real time imaging or ultrastructural visualization methods. Among other findings, we show that the DNA Flap acts as viral promoting element for the uncoating of integral capsids, docked at the nuclear pore, allowing translocation of the viral DNA through the nuclear pore.

An important part of the VMV G5 activity is dedicated to the application of the lentiviral vector technology for vaccination purposes. Lentiviral vectors represent very efficient vaccination tools. Several recent publications, including ours, have highlighted the potential of lentiviral vectors for eliciting cellular responses against tumor antigens. We adapt this vaccination strategy for the therapeutic vaccination against AIDS. We are working on several models: humanized HLA transgenic mice and non-human primates. We recently showed that immunization with a single dose of vector particles induced strong, diversified and long-lasting CTL responses. We also showed that a single minute dose of lentiviral vector particles encoding the E-glycoprotein of West Nile induced a long-lasting, protective and sterilizing humoral immunity, only one week after priming.

The projects of the VMV unit are in direct continuation with our three main research topics: basic virology for the understanding of the early steps of HIV-1 replication, vectorology/gene therapy, and lentiviral vector based vaccination.


Publications 2006 of the unit on Pasteur's references database

Activity Reports 2006 - Institut Pasteur
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