Oportunidades de Dissertação

Instituição: i3S – Instituto de Investigação e Inovação em Saúde, Instituto de Biologia Molecular e Celular

Nome do Responsável: Inês Loureiro.

Contacto: ines.loureiro@ibmc.up.pt

Tema da Dissertação: Bioengineered outer membrane vesicles as a platform for producing multivalent fish vaccines.

Descrição da Dissertação: With the increasing global population and demand for seafood, aquaculture has become essential for ensuring the supply of nutritious, high-quality fish products. As wild fisheries reach their limits, aquaculture production will need to double by 2050 to meet global demand. Infectious diseases remain one of the major challenges in fish farming, leading to significant economic losses, high mortality rates, and reduced animal welfare. This highlights the urgent need for effective disease control strategies.

Vaccination is a key preventive measure that reduces reliance on antibiotics, helping to combat the growing issue of antimicrobial resistance. Despite its potential, current vaccines offer limited disease coverage and often lack efficacy, making the development of new, more effective vaccines a critical priority.

Naturally derived from Gram-negative bacteria, outer membrane vesicles (OMVs) are gaining attention as novel tools in vaccinology. These vesicles present antigens in their native conformation and carry virulence-associated molecules, enabling strong immune responses—often without requiring adjuvants. This project aims to develop engineered OMVs derived from the fish pathogen Photobacterium damselae subsp. piscicida (Phdp) as a novel antigen delivery platform. 

Our initial strategy used ectopic expression of heterologous antigens fused to a Sec signal peptide (SP) at the N-terminus, directing them to the Phdp bacterial periplasm under the control of a strong Phdp-specific promoter. While this approach showed partial success, not all antigens were effectively incorporated into OMVs, revealing the need for improved loading techniques.

To overcome this, we are now exploring new molecular strategies that involve fusing antigens to outer membrane-associated proteins, such as OmpA-like proteins and lipoproteins. These fusion approaches aim to guide the antigens directly into the OMVs, enhancing their incorporation efficiency.

Ultimately, our goal is to establish a robust and flexible platform, for producing multivalent vaccines that can target both established and emerging pathogens in aquaculture, capable of addressing the practical needs of aquaculture farmers worldwide.

Período: 6 meses.