title: Effect of dietary arginine on the immune response and gene expression in head kidney and spleen following infection of Jian carp with Aeromonas hydrophila.
abstract: This study was conducted to test the hypothesis that elevated dietary arginine enhances immunity of juvenile Jian carp (Cyprinus carpio var. Jian). Fish were fed graded levels of dietary arginine for 9 weeks. Subsequently, a challenge test was conducted by injection of Aeromonas hydrophila. Head kidney and spleen weights, as well as erythrocyte and leukocyte counts were significantly influenced by dietary arginine levels. A similar trend was also observed for hemagglutination titre, serum lysozyme activity, IgM concentration, C3 and C4 content. The highest survival rates following A. hydrophila infection were obtained in fish fed the diets containing arginine at 16.1-21.9 g/kg diet. Phagocytic activity of leukocytes was significantly enhanced by dietary arginine supplementation. In contrast, acid phosphatase activity significantly decreased with dietary arginine levels. Dietary arginine levels did not have a significant effect on the total iron-binding capacity. Gene expression of TNF-α and TGF-β in head kidney significantly increased with dietary arginine levels up to 21.9 g/kg diet, and decreased thereafter. Fish fed the basal diet exhibited the highest IL-10 mRNA expression level. Gene expression of IL-1β and TOR increased with dietary arginine addition, reaching a plateau at 18.5 and 21.9 g arginine/kg diet, respectively. In spleen, higher IL-1β and TNF-α gene expressions were obtained in fish fed the diets containing 24.5 g arginine/kg diet than in fish fed the other dietary treatments. TGF-β mRNA expression levels were significantly lower in fish fed the diets containing ≤21.9 g arginine/kg diet. IL-10 and TOR mRNA expression levels were lower in fish fed 16.1 g arginine/kg diet, while 4E-BP mRNA expression levels increased with dietary arginine levels up to 12.7 g/kg diet and decreased thereafter. Our results indicate that arginine has beneficial effects on regulating mRNA expression of inflammatory cytokines, as well as TOR and 4E-BP and improving humoral and cellular immunity, therefore enhancing disease resistance of fish.
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Gangfu
authors.initials: G
authors.lastname: Chen
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China; Fish Nutrition and Safety in Production Sichuan University Key Laboratory, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China; Fish Nutrition and Safety in Production Sichuan University Key Laboratory, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China; Fish Nutrition and Safety in Production Sichuan University Key Laboratory, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Weidan
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China; Fish Nutrition and Safety in Production Sichuan University Key Laboratory, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Shengyao
authors.initials: S
authors.lastname: Kuang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Tang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Wuneng
authors.initials: W
authors.lastname: Tang
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Zhang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China; Fish Nutrition and Safety in Production Sichuan University Key Laboratory, Sichuan Agricultural University, Ya'an 625014, China. Electronic address: zhouxq@sicau.edu.cn.
authors.forename: Xiaoqiu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an 625014, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China; Fish Nutrition and Safety in Production Sichuan University Key Laboratory, Sichuan Agricultural University, Ya'an 625014, China. Electronic address: fenglin@sicau.edu.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
mesh_terms: D016980:Aeromonas hydrophila; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002347:Carps / Q000235:genetics / Q000276:immunology*; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D016207:Cytokines / Q000235:genetics; D004032:Diet; D060467:Disease Resistance / Q000187:drug effects; D004906:Erythrocyte Count; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology*; D029941:Fish Proteins / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary*; D060226:Head Kidney / Q000187:drug effects* / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood; D007958:Leukocyte Count; D009113:Muramidase / Q000097:blood; D009929:Organ Size / Q000187:drug effects; D010587:Phagocytosis / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D013154:Spleen / Q000187:drug effects* / Q000276:immunology; D058570:TOR Serine-Threonine Kinases / Q000235:genetics
chemical_list: D003176:Complement C3; D003181:Complement C4; D016207:Cytokines; D029941:Fish Proteins; D007075:Immunoglobulin M; D012333:RNA, Messenger; D001120:Arginine; D058570:TOR Serine-Threonine Kinases; D009113:Muramidase
keywords: Arginine; Cyprinus carpio var. Jian; Disease resistance; Immune response