博士 / 國立臺灣海洋大學 / 水產養殖學系 / 102 / The effect of carrageenan on the immune response of white shrimp Litopenaeus vannamei was examined in vitro and in vivo. In shrimp hemocytes treated with 1 mg ml-1 carrageenan, the percentage of large cells among hemocytes decreased from 89% to 53% after 120 min, whereas the percentage of live cell decreased from 70% to 51% after 120 min. Shrimp hemocytes receiving carrageenan at 1 mg ml-1 experienced change in cell size, reduction in cell viability, increased PO activity, serine proteinase activity, and RB in vitro.
Shrimp received carrageenan via immersion at 200, 400 and 600 mg l-1 after 3 h and orally at 0.5, 1.0 and 2.0 g kg-1 after 3 weeks showed higher proliferation of hematopoietic tissues (HPTs) together with increases in hemocyte count and other immune parameters including phenoloxidase (PO) activity, respiratory burst (RB), superoxide dismutase (SOD) activity, lysozyme activity, and hemolymph protein.
Immune parameters of shrimp that received 400 mg l-1 carrageenan decreased less, whereas the immune parameters of control shrimp decreased more, compared to the background values at 72~144 h post-stress to 5 mg l-1 ammonia-N. Shrimp subjected to ammonia stress showed a greater decrease in PO activity, compared to the decrease of RB and SOD activity indicating progressive perturbation of humoral immunity. Shrimp received carrageenan exhibited a protective effect against ammonia stress.
Shrimp that fed a diet containing carrageenan at 0.5 g kg-1 after 3 weeks significantly up-regulated gene expressions of several immune related proteins including liopopolysaccharide and β-glucan binding protein (LGBP), lectin, peroxinectin (PX), integrin β, prophenoloxidase activating enzyme (ppA), prophenoloxidase (proPO) I, proPO II, α2-macroglobulin (α2-M), cytosolic manganese superoxide dismutase (cytMnSOD), mitochondrial manganese superoxide dismutase (mtMnSOD), glutathione peroxidase (GPx), catalase, lysozyme, penaeidin 3a, heat shock protein (HSP) 70, transglutaminases (TGS) I, TGS II.
The immune parameters of shrimp that received carrageenan via immersion and orally increased to a plateau after 3 h and after 3 weeks, but decreased after 5 h and 6 weeks, respectively. Resistances of shrimp against Vibrio alginolyticus and white spot syndrome virus (WSSV) were higher over 24-144 h and 72-144 h, respectively in shrimp that received carrageenan at 600 mg l-1 via immersion after 3 and 5 h. Phagocytosis and clearance of V. alginolyticus remained high in shrimp that had received carrageenan via immersion after 5 h and orally after 6 weeks, respectively.
Carrageenan effectively triggers an innate immunity due to occurrence of degranulation, change in cell size and viability, and increases in PO activity and RB in vitro, and increases mitotic index of HPT, immune parameters, gene expressions and resistance against pathogens in vivo. Shrimp received carrageenan via immersion and orally exhibited immunocompetence in phagocytosis and clearance of V. alginolyticus, and resistance to V. alginolyticus and WSSV despite the trend in immune parameters to recover to background values.
In conclusion, shrimp incubated in carrageenan, a extract from red seaweed polysaccharide activates the innate immune system as an evidence in occurrence of degranulation, increase in PO activity, serine proteinase activity and release of superoxide anion. Shrimp received carrageenan increased immune parameters, and enhanced resisance against V. alginolyticus and WSSV infections, showed protective response to ammonia stress and showed immunocompetence. Carrageenan is an excellent immunostimulant, and can be added in the diet, and applied in shrimp farming to modulate innate immunity of shrimp and increase its resistance to Vibrio and WSSV pathogen for sustainable aquaculture.
| Identifer | oai:union.ndltd.org:TW/102NTOU5086010 |
| Date | January 2014 |
| Creators | Chen, Yu-Yuan, 陳鈺元 |
| Contributors | Chen, Jiann-Chu, 陳建初 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 97 |
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