title: Recombinant goose-type lysozyme in channel catfish: lysozyme activity and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection.
abstract: The objectives of this study were: 1) to investigate whether recombinant channel catfish lysozyme-g (CC-Lys-g) produced in Escherichia coli expression system possesses any lysozyme activity; and 2) to evaluate whether channel catfish lysozyme-g plasmid DNA could be used as an immunostimulant to protect channel catfish against Aeromonas hydrophila infection. Recombinant CC-Lys-g produced in E. coli expression system exhibited significant (P < 0.05) lytic activity against Gram-positive Micrococcus lysodeikticus and Gram-negative A. hydrophila. When pcDNA3.2-vectored recombinant channel catfish lysozyme-g (pcDNA-Lys-g) was transfected in channel catfish gill cells G1B, the over-expression of pcDNA-Lys-g offered significant (P < 0.05) protection to G1B cells against A. hydrophila infection. When channel catfish were intraperitoneally injected with pcDNA-Lys-g along with an adjuvant QCDCR, the transcriptional level of Lys-g was significantly (P < 0.05) increased. When pcDNA-Lys-g injected fish was challenged with a highly virulent A. hydrophila strain AL-09-71, pcDNA-Lys-g offered 100% protection to channel catfish at two days post DNA injection. Macrophages of fish injected with pcDNA-Lys-g produced significantly (P < 0.05) higher amounts of reactive oxygen species and nitric oxide than that of fish injected with pcDNA vector alone at two days post DNA injection. Taken together, our results suggest that pcDNA-Lys-g could be used as a novel immunostimulant to offer immediate protection to channel catfish against A. hydrophila infection.
authors: Aquatic Animal Health Research Unit, USDA-ARS, 990 Wire Road, Auburn, AL 36832, USA. Julia.Pridgeon@ars.usda.gov
authors: Julia W
authors: JW
authors: Pridgeon
authors: Phillip H
authors: PH
authors: Klesius
authors: Paul J
authors: PJ
authors: Dominowski
authors: Robert J
authors: RJ
authors: Yancey
authors: Michele S
authors: MS
authors: Kievit
mesh_terms: D000193:Actinomycetales Infections / Q000235:genetics / Q000517:prevention & control / Q000662:veterinary*; D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016980:Aeromonas hydrophila / Q000276:immunology / Q000472:pathogenicity / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D005393:Fish Diseases / Q000235:genetics / Q000517:prevention & control*; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000517:prevention & control / Q000662:veterinary*; D007059:Ictaluridae / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D008837:Micrococcus / Q000276:immunology / Q000502:physiology; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary
chemical_list: D000276:Adjuvants, Immunologic; D018076:DNA, Complementary; D029941:Fish Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D009113:Muramidase
keywords: Aeromonas hydrophila; Channel catfish; Immunostimulant; Lysozyme-g