Study On The Immune Response Of Common Carp(Cyprinus Carpio) Induced By Oral Immunization

In the present study, the endotoxin and exotoxin were prepared from the Edwardsiella tarda and the inactived bacteria cell, purified endotoxin and exotoxin were made into liposome contained antigens with lecithin and cholesterol. There was no protein founded in the purified endotoxin through SDS-PAGE gel electrophoresis and comparing silver staining and Coomassie staining, and the output ratio of the endotoxin was 5.6%. Much protein in different molecular sizes were detected from the purified exotoxin of Edwardsiella tarda through SDS-PAGE gel electrophoresis, and most of it ranged from 30 to 50KD. The liposomally incorporated bacteria obtained from film diffusion method looked like transparent sphere or ellipsoid under the microscope, and the diamter ranged from 1 to 10μm. The average diamter of liposomally incorporated endotoxin and liposomally incorporated exotoxin got from freeze thawing method ranged form 1 to 1.4μm. All the immunogen was immuned common carp(Cyprinus carpio) orally. The aim of detecting the special immune parameters involving the antibody titer,γglobulin percent and content of serum and the non-special immune parameters containing lysozyme, phagocytic activity of neutrophil and superoxide dismutase (SOD) activity was to study the influence of different immunogen, immune dosage, immune frequency and environmenal temperature on the immune response.The results of this study were as follows: there was no significant difference in the antibody titer,γglobulin percent and content of serum between the liposomally incorporated bacteria and the single bactera. But, the liposomally incorporated bacteria could increase phagocytic activity of neutrophil and lysozyme significantly, the single bacteria could not. There were many similar points in the immune response regulation between the whole bacteria antigen and the endotoxin antigen, otherwise, the endotoxin antigen was superior to the bacteria antigen in the field of activating some of the non-special immune parameters. The increasing of immune frequency could improve the antibody titer,γglobulin percent and content of serum significantly, while it restrained the phagocytic percent of neutrophil, lysozyme and SOD activity of immune carp significantly. Otherwise, environmenal temperature also could affect the immune parameters remarkable. The antibody titer, lysozyme and SOD activity of low temperature group was higer than those of high temperature group remarkably, while the phagocytic activity of neutrophil in the low temperature group was lower than the high one significantly. The results indicated that there was no significant difference in the humour immune response regulation among different immunogen and among immunogen made by different mathods, the increasing of immune frequency could improve not only the serum antibody titer, but also theγglobulin percent and content of serum significantly, while it restrained some non-special immune parameters. Different environmenal temperature affected the immune indexes of carp significantly after the oral immne.