Periodic Reporting for period 1 - PathoGelTrap (New Blue Revolution through a pioneering pathogen-trapping technology based on bioselective hydrogel-forming proteins)
Période du rapport: 2020-06-01 au 2021-05-31
The PathogelTrap Project proposes to transform the future of aquaculture driving a change of paradigm in disease management practices. The project will provide the industry with a pioneering pathogen-trapping technology, able to target and remove specific pathogenic agents directly from the water. At the core of our science-enabled technology are 2 topics revolutionizing the scientific community: affibodies (AFBs) and the Liquid-Liquid-Phase Separation phenomenon (LLPS). These liquid-droplet forming proteins often present the so-called Low Complexity Regions (LCRs), with a lower diversity of residues, and follow a phase transition dynamic: the monomeric proteins self-assemble into liquid droplets (liquid-liquid phase separation) which later evolve into a gel state, i.e. hydrogel (liquid-to-gel transition).
Viral Nervous Necrosis (VNN) also known as Viral Encephalopathy and Retinopathy (VER), is a hazardous and devastating disease of many species of cultured and marine fish worldwide. It is caused by Betanodaviruses, a serious concern especially in larvae and juvenile fish. This virus infects most of the cultured fish causing severe mortality. European sea bass (Dicentrarchus labrax L.) is a very valuable fish species in Mediterranean countries, and it is currently one of the main cultured fish species in Europe. However, different infectious diseases can affect its production and cause important economic impacts in the aquaculture industry. One of the most significant diseases affecting D. labrax is viral encephalopathy and retinopathy (VER), which is characterized by severe damage to nervous tissues.
Enteric redmouth disease (ERM) is a disease generally accruing amongst cultured salmonids, causing significant economic losses to the fish-farming industry. The disease is caused by Yersinia ruckeri, a gram-negative bacteria first isolated from rainbow trout in Idaho, USA and currently found throughout North and South America, Europe, Australia, South Africa, the Middle East and China.
Towards the use of PGT products in two selected environments, marine and fresh water, we have selected the best LCR components derived from the in vitro phase separation assays in real fish farms conditions (hCPEB3-S6, DBP1 Nt+Ct and mHP1α). Also, the selected antigens (the P-domain of Betanodavirus RGNNV and OmpF membrane protein from Yersinia ruckeri) have been defined. The new selected binder scaffold (rcSso7d) has presented good results, particularly with Betanodavirus. This will contribute to high specificity and maximum efficiency. Also, we have avoided environmental drawback via the selection of LCRs with no amyloid properties. During the screening each LCR candidate has been selected according to the expression already described in E. coli and focused on small size and high yields of production: with the subsequent scaling-up step in mind, the LCR-AFB chimera must be capable of being produced in large concentrations and at low cost.
Also the characterization of the operation conditions typical of both production environments (marine and fresh water farms) are used in the selection and design of the molecular components. This will contribute to the efficacy and the safety of the PGT products, both from the animal welfare and an environmental safety perspective.
The use of PGT as an integral part of the biosecurity strategy of the aquaculture sector will improve the custom-made-tool-box for disease prevention. This will translate into better health management, improved animal welfare, more precise pathogen removal, reduced transfer of pathogen charge to the environment.