Expression of Interleukin-1 beta protein in vitro, ex vivo and in vivo salmonid models

Interleukin-1 beta (IL-1 beta) is one of the first cytokines expressed during immune responses, and its levels are affected by many factors, including stress. To date, it has only been possible to measure IL-1 beta transcript (mRNA) expression quantitatively in fish using qPCR. This is because previous studies that measured IL-1 beta protein concentrations in these taxa used western blotting, which only provides qualitative data. To advance our knowledge of fish IL-1 beta biology, and because post-translational processing plays a critical role in the activation of this molecule, we developed a quantitative enzyme-linked immunosorbent assay (ELISA) to accurately measure the concentration of IL-1 beta protein in several cell cultures and in vivo in salmonids. We compared changes in IL-1 beta protein levels to the expression of its mRNA. The developed ELISA was quite sensitive and has a detection limit of 12.5 pg/mL. The tools developed, and information generated through this research, will allow for a more accurate and complete understanding of IL-1 beta's role in the immune response of salmonids. The assay described here has the potential to significantly advance our ability to assess fish health and immune status.

Automated summary

In this study, a quantitative enzyme-linked immunosorbent assay (ELISA) was developed to accurately measure the concentration of IL-1 beta protein in salmonids. By comparing changes in IL-1 beta protein levels to the expression of its mRNA, a more accurate and complete understanding of IL-1 beta's role in the immune response of salmonids can be achieved.