Biovi : a research program for reducing chemical input in vine and wine

International audienceDecrease of chemical inputs during vine management and winemaking is of great importance from a political and societal point of view. In our ongoing project we propose alternative tools to chemicals in the vineyard and the cellar. We have compared a conventional vineyard protection strategy to an alternative strategy using copper and biocontrol products (Biocontrol) against downy and powdery mildews. Both strategies were compared regarding sanitary quality, berries and/or must enological parameters, and physical, biochemical and biological characteristics (berry surface observation, proteomic, metabolomic, volatilomic, metagenomic analyses). Musts obtained with both strategies were then used to assess compatibility with wine bioprotection. Bioprotection is an enological practice that consists of supplying microorganisms in order to reduce the use of sulfites during prefermentation winemaking steps. This practice was evaluated and the efficiency of non-Saccharomyces yeast was assessed (competition with indigenous yeast) as an alternative to sulfites requirement. The antioxidant capacity of wines obtained was also assessed. The four wines categories obtained from combination of Copper-Biocontrol/Conventional and Bioprotection/sulfites will then be compared by tasting and also by metabolomic and volatilomic analyses in order to study matrix changes and to identify putative biomarkers of each of these two bioprocesses

Design of a HIV-1-derived HLA-B07.02-restricted polyepitope construct.

International audienceOBJECTIVE: To design a vaccine construct containing various but conserved HIV-1-derived epitopes and generating broad CD8 T cell responses. METHODS: HLA-B7 transgenic H-2KD KO transgenic mice were used to identify potential new HLA-B07.02-restricted HIV-1-derived epitopes. Immunological recognition of these epitopes was confirmed by IFN-gamma ELISpot assays with PBMCs from HLA-B*0702 HIV-1-infected individuals. For these peptides as well as others previously identified, the capacity to induce cross-reactive responses against their frequent allelic variants was evaluated in the mouse model. A set of epitopes inducing strong T cell responses against various and conserved regions of HIV-1 was selected. A DNA vaccine was designed to express them as a unique antigen with or without a three amino acid ARY extension flanking each epitope. The spectrum of CD8 T responses generated by polyepitope constructs was tested in HLA-B7 transgenic mice. RESULTS: Five new epitopes were identified in accessory and regulatory HIV-1 proteins. Twelve HLA-B07.02-restricted epitopes were selected on the basis of their structural conservation and cross-reactive immunogenicity. The ARY N-terminal extension flanking each epitope markedly increases their affinity for TAP and the use of this flanking extension in polyepitope vaccine has a sizable advantage to induce CD8 T cell cytotoxic responses in mice following DNA immunization. CONCLUSION: The HLA-B7 mouse model allows to rapidly identify various HIV-1-derived epitopes of vaccine interest. Grouped in a polyepitope construct designed to increase their processing, this vaccine may be suitable for inducing multiple and relevant HIV-1-specific CTL responses in humans