Optimizing an Immune Function Assay for Sablefish (Anoplopoma fimbria), an Emerging Aquaculture Species

Wild capture rates have remained relatively constant since the 1980s, while global fish production in cultured systems has risen dramatically. Sablefish, Anoplopoma fimbria, is a developing aquaculture species that could be successful on the commercial market because of its characteristic buttery flavor. However, sablefish physiology and development is not fully characterized. Disease is always a concern in fish culture, and a baseline understanding of sablefish immune health is needed to establish a sustainable sablefish aquaculture industry. Phagocytic cells are critical cells of the immune system, and include: B-lymphocytes, neutrophils and macrophages. Phagocytic cells have three main functions when protecting fish from bacteria and viruses: they recognize and engulf invading pathogens; they kill the invaders efficiently by producing reactive oxygen species (ROS), and finally they dampen the ROS response to prevent damage to surrounding tissues. This project establishes the methodology to: (1) enrich sablefish phagocytic cells in vitro and (2) optimize immune function assays. The assays include: engulfment with latex beads and labeled bacteria; superoxide production measured by a color changing reaction with a chromage (WST); and antioxidant production. This presentation will focus on improved methods to enrich for phagocytic cells from the anterior kidney of sablefish and an optimized assay to measure superoxide production in phagocytic cells.