title: Analysis of skin and secretions of Dybowski's frogs (Rana dybowskii) exposed to Staphylococcus aureus or Escherichia coli identifies immune response proteins.
abstract: The aim of the present study was to investigate responses in Dybowski's frogs (Rana dybowskii) exposed to bacteria, using proteomic and transcriptomic approaches. Staphylococcus aureus and Escherichia coli were used as representative Gram-positive and Gram-negative bacteria, respectively, in an infectious challenge model. Frog skin and skin secretions were collected and protein expression in infected frogs compared to control frogs by two-dimensional gel electrophoresis, silver staining, and image analysis. Proteins that demonstrated differential expression were analysed by mass spectrometry and identified by searching protein databases. More than 180 protein spots demonstrated differential expression in E. coli- or S. aureus-challenged groups and, of these, more than 55 spots were up- or down-regulated at least sixfold, post-infection. Proteins with a potential function in the immune response were identified, such as stathmin 1a, annexin A1, superoxide dismutase A, C-type lectin, lysozyme, antimicrobial peptides, cofilin-1-B, mannose receptor, histone H4, prohormone convertase 1, carbonyl reductase 1 and some components of the Toll-like receptor (TLR) signalling pathway. These molecules are potential candidates for further investigation of immune mechanisms in R. dybowskii; in particular, TLR-mediated responses, which might be activated in frogs exposed to pathogenic bacteria as part of innate immune defence, but which might also impact on adaptive immunity to infection.
authors.affiliation: Wildlife Resources College, Northeast Forestry University, He Xing Road 26, Harbin, China.
authors.forename: Xiang-Hong
authors.initials: XH
authors.lastname: Xiao
authors.affiliation: Wildlife Resources College, Northeast Forestry University, He Xing Road 26, Harbin, China.
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Miao
authors.affiliation: Technology Centre, Heilongjiang Entry-Exit Inspection and Quarantine Bureau, Gan Shui Road 9, Harbin, China. Electronic address: yigangxu_china@sohu.com.
authors.forename: Yi-Gang
authors.initials: YG
authors.lastname: Xu
authors.affiliation: Wildlife Resources College, Northeast Forestry University, He Xing Road 26, Harbin, China.
authors.forename: Jing-Yu
authors.initials: JY
authors.lastname: Zhang
authors.affiliation: Wildlife Resources College, Northeast Forestry University, He Xing Road 26, Harbin, China.
authors.forename: Long-Hui
authors.initials: LH
authors.lastname: Chai
authors.affiliation: Wildlife Resources College, Northeast Forestry University, He Xing Road 26, Harbin, China.
authors.forename: Jia-Jia
authors.initials: JJ
authors.lastname: Xu
mesh_terms: D029845:Amphibian Proteins / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional / Q000662:veterinary; D004926:Escherichia coli / Q000502:physiology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D007091:Image Processing, Computer-Assisted; D007113:Immunity, Innate; D013058:Mass Spectrometry / Q000662:veterinary; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D011898:Ranidae; D016622:Silver Staining / Q000662:veterinary; D012867:Skin / Q000276:immunology* / Q000382:microbiology; D013207:Staphylococcal Skin Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000502:physiology*; D059467:Transcriptome
chemical_list: D029845:Amphibian Proteins; D020543:Proteome
keywords: Immune responses; Microbial infection; Proteomic analysis; Rana dybowskii