Water Oxygen Content Affects Distribution of T and B Lymphocytes in Lymphoid Tissues of Farmed Sea Bass (Dicentrarchus Labrax)

Abstract

Abstract:Intensive aquaculture systems have stimulated proper management in order to limit stressful stocking conditions and environmental impact. This should improve fish wellness and counteract adverse water characteristics such as high concentrations of carbon. The oxygen can be considered a key factor since critical conditions leading to chronic rise of blood catecholamines can depress the number and Oxygen-carrying capacity of erythrocytes. In this research, we evaluated the effects of variation in water oxygen (from 6 ± 1 to 13 ± 1 mg/L) on lymphocytes density in sea bass by using flow cytometry and immunohistochemistry. Gut, gill, and thymus T-cells were significantly enhanced in percentage in hyperoxygenated fish compared with normo-oxygenated group, while Peripheral Blood Leukocytes (PBL), head kidney, and spleen T-cells were not significantly different. Contrarily, in PBL, head kidney and spleen hyper-oxygenation treatment provoked an enhancement of B lymphocyte percentages. The distribution of positive T-cells in hyper-oxygenated fish varied in the organs and followed the relative increments/decrements observed in flow cytometry. This study remarks the sensitivity of sea bass adaptive immunocytes to oxygen concentration, evidenced by the modification of parameters. Sea bass culture under high-flow water recycling and at around 12-13 mg/L oxygen concentrations is therefore suggested to enhance the immune response capacity.

Comparative study of haematology of two teleost fish ( Mugil cephalus and Carassius auratus ) from different environments and feeding habits

“…It is known that WBC play a major role in the immune defensive system of fish, whereas TC are blood cells that serve mainly to form protective barriers (Magnadottir 2006). The numbers of WBC and TC may change in relation to various environmental parameters or stimuli such as infection, as well as multiple other factors, from the age of fish to species characteristics or nutritional differences (Romano et al 2017), which may explain the variations in WBC and TC values observed herein in mullets compared to goldfish, probably reflecting the different feeding habits of the two fish species under study. Notably, in a previous study it was reported that M. cephalus showed the lowest WBC and TC values with respect to two other seawater carnivores species, namely Sparus aurata and Dicentrarcus labrax (Fazio et al 2016).…”

Immunotherapy Using Oxygenated Water and Tumor‐Derived Exosomes Potentiates Antitumor Immune Response and Attenuates Malignancy Tendency in Mice Model of Breast Cancer

“…For example, it has been shown that the effect of chemotherapy is significantly increased immediately after hyperbaric oxygen therapy [ 42 ]. Other investigations indicated that oxygen potently affects regulatory immune responses which are dominant within the tumor loci [ 17 , 18 ]. Indeed, hypoxia promotes Treg recruitment to the site of tumor, enhances their activity in the tumor foci, and suppresses antitumor effector T cell response [ 19 ].…”

“…Accordingly, oxygenation of tumor cells interferes with their proteomic and genomic changes and destroys them [14][15][16]. In addition, the hypoxic condition within tumors inhibits antitumor immune responses [17][18][19].…”

Ozone nanobubble treatments improve survivability of Nile tilapia (Oreochromis niloticus) challenged with a pathogenic multidrug-resistantAeromonas hydrophila

“…Previous studies suggested that high level of oxygen improved the immunocompetence in fish (Bowden, 2008; Cecchini and Saroglia, 2002). Romano et al (2017) revealed that 12 −13 mg/L oxygen increased immune response performance of sea bass ( Dicentrarchus labrax ).…”