Plasma Proteome Responses in Salmonid Fish Following Immunization

Area of Science:

• Aquaculture and Fish Immunology
• Proteomics and Mass Spectrometry
• Animal Health and Veterinary Science

Background:

• Vaccine efficacy varies significantly among individuals due to genetic and immunological differences, a known issue in humans but understudied in fish.
• Understanding individual immune responses in fish is critical for improving vaccine effectiveness and disease management in aquaculture.

Purpose of the Study:

• To investigate the plasma proteome response to vaccination in individual rainbow trout using repeated non-lethal blood sampling.
• To identify temporal changes in plasma protein abundance following immunization and correlate these with immune responses.
• To provide insights into fish immune variability and identify potential protein biomarkers for vaccine development.

Main Methods:

• Six rainbow trout were immunized with hen egg-white lysozyme (HEL) and sampled repeatedly over 84 days.
• Label-free liquid chromatography-mass spectrometry (LC-MS) was used to quantify 278 plasma proteins.
• Proteomic data was analyzed to identify proteins with significant temporal variation and individual differences.

Main Results:

• Individual antibody responses to HEL varied in timing and magnitude.
• Plasma proteome variation was primarily driven by individual differences among fish.
• A subset of 41 proteins (15% of detected) showed significant temporal changes, clustering into five distinct response groups, including immune and acute phase molecules.

Conclusions:

• This study characterizes the fish plasma proteome response to immunization, highlighting individual variability.
• Identified temporal protein markers can inform vaccine development and immune challenge experiment design in fish.
• The findings contribute to a better understanding of fish immunology and personalized approaches to disease prevention.