T cell repertoire analysis development of immunological tools to evaluate vaccine protection in key european farmed fish species

Project summary

Disease prevention is essential to enhance production and sustainability in European fish farming. De-spite being the fastest-growing food production sector, aquaculture is hampered by infectious diseases. Preventing viral outbreaks and opportunistic infections requires understanding fish immune responses to pathogens and vaccines. While salmon vaccines have reduced antibiotic use, effective strategies against many viral and bacterial diseases in farmed fish are lacking. Current vaccine efficacy measures focus on B cell/antibody responses, but successful vaccines need both B and T lymphocyte activation.

While T cell responses are crucial for protection, they are not well understood in fish, due to limited tools and species diversity. Fish possess conventional T cell subsets (cytotoxic, helper, regulatory), but their dynamics and interactions with B cells are not well known. γδ T cells are also present in fish, this kind of innate-like T cells seem to play important roles in pathogen control and antibody production, but studies on these cells in farmed fish are scarce. In human and mice, high throughput sequencing (HTS) methods have become critical tools for studying the T cell repertoires in many different contexts, including infection and vaccination. The general aim of AquTRep is to implement HTS to monitor and characterize T cell mediated immune responses in farmed fish. Expanding on tasks developed by PAHW partners, AquTRep brings together experts in fish T cells and immune repertoires to extend TCR repertoire analysis to all main T cell subsets, based on genomic resources available for the most relevant fish species of European aquaculture. This will provide a key immunological toolkit for vaccine validation and evaluation.