In this project we succeeded to modify a particular strain of LAB, L. lactis, and to optimize the conditions within which this LAB was able to deliver a vaccine antigen to the host (cells).
For the proof of principle we used a previously established vaccine antigen by our group, the spring viraemia of carp virus G protein (SVCV-G), and common carp or zebrafish as fish species.
In this project we succeeded to show that modified L.lactis can deliver the SVCV-G antigen to carp cell lines in vitro and to zebrafish larvae in vivo.
For the initial validation, bacteria were mixed in vitro with carp cells and after 3 days antigen expression in fish cells was evaluated leading to approximately 30% of the cells expressing the vaccine antigen.
For the preliminary validation in vivo, bacteria were intramuscularly injected in zebrafish larvae and antigen-expressing cells were identified already 48h after injection.
Altogether, our in vitro and in vivo results show that modified LAB can be used in fish to deliver vaccine antigens. This proof-of-principle will allow us to make the next step and test the possibility to deliver these modified bacteria to fish by bath or mixed with the feed, and to vaccinate commercially relevant species including but not limited to common carp, Tilapia, trout, salmon etc...
Details about the data will be published in an open access journal, but the manuscript is currently under preparation.
The results of the project have already been reported ot the industry through so called 'Industrial Forum' organized through a collaborative project TargetFish
http://targetfish.eu/(s’ouvre dans une nouvelle fenêtre) Furthermore a short animated power point or a video will be generated following the publication of the results. These will explain in technical and layman terms the major outcomes of the project.
