The efficacy of a commercial β-glucan preparation, EcoActiva™, on stimulating respiratory burst activity of head-kidney macrophages from pink snapper (Pagrus auratus), Sparidae

This study investigated the in vitro effects of a commercial beta -glucan preparation, EcoActiva (TM), on the, respiratory burst activity of head-kidney macrophages isolated from pink snapper (Pagrus auratus), a marine fish cultured in Australia. Macrophages incubated with EcoActival (TM) displayed morphological characteristics of activation, and were stimulated to produce superoxide. Pre-incubation with low levels of EcoActiva (TM) significantly increased the response to phorbol myristate acetate (PMA) and lipopolysaccharide (LPS), indicating that EcoActiva (TM) could prime these macrophages. Co-culturing macrophages with both LPS and PMA, or EcoActiva (TM) and PMA, increased burst activity compared with the response to PMA alone, however, this increase was additive and not synergistic. These results suggest that EcoActiva (TM) is able to stimulate non-specific immunity in snapper through increased respiratory burst activity of macrophages, an important component of the host defence network. (C) 2001 Academic Press.