Studies on the effects of LPS, ß‐glucan and metabolic inhibitors on the respiratory burst and gene expression in Atlantic salmon macrophages

Abstract

Reactive oxygen species (ROS) production in macrophage-like cells is induced as an antimicrobial defence against invading pathogens. In this study, we have explored how different stimuli and metabolic inhibitors affect the level of respiratory burst in Atlantic salmon (Salmo salar L.) head kidney macrophage-like cells. Cells stimulated in vitro by bacterial lipopolysaccharide (LPS) and ß-glucan showed increased production of ROS compared to unstimulated cells. Both stimulation and costimulation by curdlan (ß-glucan) induced a higher production of ROS compared to stimulation and costimulation by LPS. Metabolic inhibitors co-incubated with the stimulants did not, in most cases, perturb the level of ROS generation in the salmon macrophage-like cells. The NAD content as well as the NAD /NADH ratio increased in curdlan and LPS + curdlan-stimulated cells compared to control cells, which indicated increased metabolic activity in the stimulated cells. Supporting these findings, gene analysis using real-time quantitative PCR showed that arginase-1 and IL-1ß genes were highly expressed in the stimulated cells.

Supplementation of Nucleotides to Enhance Performance and Immune Responses of Asian Seabass

“…Kidney macrophage burst activity was measured following a method from Ulvestad et al (2018) with a slight modification. Briefly, the head kidney was aseptically removed.…”

Effects of dietary yeast β-1.3/1.6-glucans on oxidative stress biomarkers in hearts and livers of rainbow trout (Oncorhynchus mykiss Walbaum), European whitefish (Coregonus lavaretus L.), and grayling (Thymallus thymallus L.)

“…As immunostimulants, â-glucans bind to macrophages and other white blood cells, improving the immunological responses of the host such as phagocytosis, lysozyme activity, respiratory burst, and cytokine release (Angulo et al 2017). Ulvestad et al (2018) reported that the head kidney macrophage-like cells of Atlantic salmon (Salmo salar L.) stimulated in vitro with bacterial lipopolysaccharide (LPS) and â-glucans showed increased production of reactive oxygen species (ROS) compared to unstimulated cells. Respiratory burst and associated ROS production also constitute important indicators of fish health status (Vera-Jimenez et al 2013).…”

“…Respiratory burst and associated ROS production also constitute important indicators of fish health status (Vera-Jimenez et al 2013). Although â-glucans are not sources of ROS, they can stimulate ROS production via different mechanisms (Thitamadee et al 2014, Ulvestad et al 2018, Sánchez-Salgado et al 2019. ROS can elicit adverse effects in aquatic organisms and induce oxidative damage to lipids, proteins, and nucleic acids (Livingstone 2001, Valavanidis et al 2006.…”