Arginine and glutamine supplementation to culture media improves theTI Arginine and glutamine supplementation to culture media improves the performance of various channel catfish immune cells

摘要

Specific components of both the innate and adaptive immune systems of channel catfish were evaluated after supplementation of culture media with arginine (ARC) and/or glutamine (GLN). Primary cell cultures of head-kidney macrophages (MO) were used for phagocytic and bactericidal assays against Edwardsiella ictaluri. Additionally, proliferation assays were conducted with naive peripheral blood lymphocytes (PBL) exposed to non-specific mitogens. To indirectly assess amino acid utilization of both MO and PBL, amino acid levels, with emphasis on ARC and GLN, were evaluated in the basal medium before and after activation or mitogenic exposure. After bactericidal and proliferation assays, the sum of the media free amino acid pool significantly (P < 0.05) decreased 23% and 45%, respectively. Glutamine levels in medium decreased by 38% and ARC by 18% during the bactericidal assay. Also, decreases of 52 and 46% from initial values were found after the proliferation assay for GLN and ARC, respectively. Macrophage phagocytosis and killing ability was significantly (P < 0.05) enhanced by ARC supplementation to culture media regardless of GLN supplementation. Proliferation of naive T-and Blymphocytes upon mitogenic exposure was significantly (P < 0.05) enhanced by supplementing ARC and GLN to the media, but limited synergistic effects were observed. These results suggest that in vitro, ARC and GLN are important substrates and immunomodulators of both innate and adaptive responses in fish leukocytes, and further highlights the potential use of ARC and GLN as immunonutrients in aquafeeds