title: In vivo effects of Escherichia coli lipopolysaccharide on regulation of immune response and protein expression in striped catfish (Pangasianodon hypophthalmus).
abstract: Lipolysaccharide (LPS), a component of outer membrane protein of gram-negative bacteria, reportedly stimulates fish immune system. However, mechanisms driving this immunomodulatory effect are yet unknown. To determine effects of Escherichia coli lipopolysaccharide on regulation of immune response and protein expression of striped catfish (Pangasianodon hypophthalmus), juvenile fish (20-25 g) were injected with 3, 15 or 45 mg E.coli LPS/kg and challenged with Edwardsiella ictaluri. Plasma cortisol and glucose were rather low and did not differ (p<0.05) among treatments. All LPS treatments differed regarding blood cell count and immune variables such as plasma and spleen lysozyme, complement activity and antibody titer, 3mg LPS/kg yielding best results; red blood cell count was not affected by LPS treatment. Accumulated mortalities after bacterial challenge were 23.4, 32.8, 37.7 and 52.5% for treatment 3, 15, 45 mg LPS/kg fish and control respectively. Proteomic analysis of peripheral blood mononuclear cells (PBMC) confirmed that LPS induced differentially over-expressed immune proteins such as complement component C3 and lysozyme C2 precursor. Regulation of other proteins such as Wap65, alpha-2 macroglobulin-3 and transferrin precursor was also demonstrated. Striped catfish injected with E.coli LPS enhanced innate immune responses.
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, NARILIS, University of Namur, Namur, Belgium. btbhang@ctu.edu.vn
authors.forename: Bui Thi Bich
authors.initials: BT
authors.lastname: Hang
authors.forename: Sylvain
authors.initials: S
authors.lastname: Milla
authors.forename: Virginie
authors.initials: V
authors.lastname: Gillardin
authors.forename: Nguyen Thanh
authors.initials: NT
authors.lastname: Phuong
authors.forename: Patrick
authors.initials: P
authors.lastname: Kestemont
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis; D002397:Catfishes / Q000276:immunology* / Q000378:metabolism*; D004926:Escherichia coli / Q000276:immunology; D029941:Fish Proteins / Q000378:metabolism*; D006403:Hematologic Tests; D007113:Immunity, Innate; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology*; D013058:Mass Spectrometry; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D020543:Proteome / Q000187:drug effects; D012698:Serologic Tests
chemical_list: D029941:Fish Proteins; D008070:Lipopolysaccharides; D020543:Proteome