RESUMO
Administration of ß-glucans through various routes, including immersion, dietary inclusion, or injection, have been found to stimulate various facets of immune responses, such as resistance to infections and resistance to environmental stress. ß-Glucans used as an immunomodulatory food supplement have been found beneficial in eliciting immunity in commercial aquaculture. Despite extensive research involving more than 3000 published studies, knowledge of the receptors involved in recognition of ß-glucans, their downstream signaling, and overall mechanisms of action is still lacking. The aim of this review is to summarize and discuss what is currently known about of the use of ß-glucans in fish.
Assuntos
Peixes/imunologia , Imunidade Inata , beta-Glucanas/metabolismo , Animais , Aquicultura , Dieta , Fatores Imunológicos/farmacologia , beta-Glucanas/administração & dosagemRESUMO
Several reports have shown the positive effects of ß-glucans on the immune. Howeverthese studies have a broad experimental design including ß-glucans compounds. Consequently, a study using the same ß-glucan molecule, administration route and experimental design is needed to compare the effects of ß-glucan across vertebrate species. For this end, during 28 days we fed four different vertebrate species: mice, dogs, piglets and chicks, with two ß-glucan molecules (BG01 and BG02). We measured the serum interleukin 2 as an indicator of innate immune response, the neutrophils and monocytes phagocytosis index as a cellular response and antibody formation as an adaptive response. The results clearly showed that the different ß-glucan molecules exhibited biologically differently behaviors, but both molecules stimulate the immune system in a similar pattern in these four species. This finding suggests that vertebrates shared similar mechanisms/patterns in recognizing the ß-glucans and confirms the benefits of ß-glucans across different vertebrate species.
Assuntos
Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , beta-Glucanas/metabolismo , Imunidade Adaptativa , Ração Animal , Animais , Suplementos Nutricionais , Cães , Feminino , Imunidade Inata , Masculino , Camundongos , Fagocitose/imunologia , Suínos , VertebradosRESUMO
This study investigated the role of endogenous cortisol on the innate immune response in matrinxã (Brycon amazonicus) fed with ß-glucan, prior to and after stressor exposure and bacterial challenge. For this, we evaluated the serum cortisol and plasma glucose levels, the serum lysozyme levels, the hemolytic activity of the complement system, and the respiratory activity of leukocytes, as well as the number of circulating erythrocytes and leukocytes of fish fed during 15 days with diets containing ß-glucan 0.1% (ß-G) or ß-glucan 0.1% + metyrapone 30 mg kg-1 fish (ß-G + MTP). Dietary MTP was used to block cortisol production. After feeding, fish were air-exposed during 3 min, to endogenously increase the cortisol levels. Following that, they were challenged with intraperitoneal injection of Aeromonas hydrophila. Results were compared with a positive control group fed with a ß-glucan-free diet. A negative control group, also fed with ß-glucan-free diet but inoculated with PBS, was established to evaluate the effect of the handling during injection. Fish were sampled prior to the stressor exposure, 30 min after exposure, and 24 h post infection (hpi). Herein we observed that dietary ß-G modulated the cortisol profile prior to and after the stressor, increasing the number and activity of leukocytes. Moreover, cortisol showed to be an efficient modulator of both humoral and cellular innate immune system by increasing lysozyme and complement activity, as well as neutrophil and monocyte populations. Our results suggest that ß-glucan-induced cortisol increase is one important mechanism to improve the innate immune response in matrinxã.