|Viral Genomics and Vaccination - CNRS URA 3015|
|HEAD||Dr. TANGY Frédéric / firstname.lastname@example.org|
|MEMBERS||BRANDLER Samantha PhD Student / CAIGNARD Grégory PhD Student / COMBREDET Chantal Technician IP / FEVRIER Michèle CR1 CNRS / GAU Mireille Secretary IP / GUERBOIS Mathilde PhD Student / KOMAROVA Anastasia Post-doc Researcher
LUCAS-HOURANI Marianne Engineer IP / MESEL-LEMOINE Mariana Post-doc Researcher / MILED Chaouki Post-doc Researcher / NAJBURG-LABROUSSE Valérie Technician IP / RUFFIE Claude Technician IP / VABRET Nicolas PhD Student / VIDALAIN Pierre-Olivier CR2 CNRS
Bivalent vaccines derived from measles vaccine
The measles vaccine has been administered to hundreds of millions of children over the last 30 years and has proved both effective and safe, inducing life-long immunity after only one injection. It is produced on a large scale in many countries and is distributed at low cost through the Expanded Program on Immunization of WHO. These characteristics led us to consider its use as a pediatric vector designed to protect children against measles and simultaneously to immunize them against other infections, such as AIDS, malaria or flaviviral diseases. These affordable recombinant vaccines might be attractive for the developing word.
With this aim, we cloned the genome of the attenuated Schwarz strain of the measles virus (MV) and made it into a vector by inserting new transcriptional units. We demonstrated the strong and stable expression from this vector of genes encoding proteins from HIV, West Nile or dengue viruses. These vectors are immunogenic in mice transgenic for MV receptor and in macaques. Recombinant vaccines expressing the HIV Env gene with deletions of the hypervariable sequences induced neutralizing antibodies and T-cell responses after a single injection. Pre-existing immunity to the vector did not affect the immunogenic potential of the vectors, since two successive injections led to the induction of anti-HIV antibodies in mice and macaques previously vaccinated with standard vaccine. An immunization/challenge experiment performed on macaques using MV-SHIV89.6 vectors demonstrated strong cellular responses and reduction of viral load during primo-infection after a rectal SHIV89.6 challenge. A clinical development program has been initiated in collaboration with GlaxoSmithKline aiming to test in phase I/II clinical trials the safety of MV-HIV vector and its capacity to induce immune responses to HIV in humans.
Concerning flaviviruses, we demonstrated that a single injection of MV vector expressing the Env protein of West Nile virus induced protection against experimental challenge in mice and monkeys. This year, we have produced a measles-dengue recombinant vaccine expressing a new combined antigen from the four serotypes of dengue virus and demonstrated its capacity to induce durable specific neutralizing antibodies to dengue virus.
Proteomics of virus-host interactions
To identify virus-host protein-protein interactions that determine virulence and pathogenesis, we have developed a large-scale mapping project based on high-throughput technologies, including recombination-based cloning and state-of-the-art yeast two-hybrid. Our screening platform is now fully operational and more than 100 screens a year can be performed. Using this tool, we have identified hundreds of virus-host protein-protein interactions, taking advantage of the unique collection of viruses available at Institut Pasteur. Besides collaborative programs developed inside or outside of this institution, our efforts now focus on two viral families of higher interest for our research group : Paramyxoviridae and arboviruses from flavivirus and alphavirus genera such as Chikungunya virus. Although we are still in the process of screening arboviral proteins, we have already identified a large number of interactions between Paramyxoviridae and cellular proteins. More than 100 cellular proteins have been characterized as potential interactors of viral factors encoded by measles, Nipah, mumps, human parainfluenza 3 or Tioman viruses. This network of virus-host interactions, which interfaces virulence factors and cellular mediators of innate immune response, will be used to identify targets for generic antiviral drugs. Functional assays are currently under development to validate these interactions and isolate interaction-disrupting compounds with antiviral activity. As part of this project, we recently demonstrated the critical role of measles virus interaction with STAT1 and Jak1 in the inhibition of type I interferon pathway by this virus. In the near future, we will develop mammalian-based systems to screen chemical compounds libraries and isolate molecules that disrupt key virus-host interactions previously identified.
Keywords: measles virus, HIV, Chikungunya virus, vaccine, interactome, yeast two-hybrid, antiviral molecules
Activity Reports 2007 - Institut Pasteur
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