title: Differential inflammatory responses of bovine foot skin fibroblasts and keratinocytes to digital dermatitis treponemes.
abstract: Bovine digital dermatitis (BDD) is a serious infectious inflammatory lameness causing pain and suffering to many cattle worldwide and which has severe economic implications. This study set out to investigate relationships between the treponemes considered causal of BDD and the local inflammatory response of the bovine host. Here we describe, for the first time, the isolation of bovine foot skin keratinocytes and fibroblasts as separate cell lineages. These cell lines were then exposed to treponeme whole-cell sonicates, and the gene expression of selected host inflammatory mediators investigated using quantitative reverse transcriptase PCR. Several genes, including those encoding RANTES/CCL5, MMP12, TNFα, TGFβ and TIMP3 were significantly upregulated in fibroblasts exposed to whole-cell sonicates derived from BDD treponeme phylotypes. For each of the above genes there were similar fibroblast expression increases for all three BDD treponeme phylotypes tested, suggesting common virulence mechanisms. With bovine foot skin keratinocytes, we were unable to detect expression of RANTES/CCL5 and after incubation with BDD treponeme constituents we were unable to observe any significant changes in expression of inflammatory mediators tested. These contrasting results suggest fibroblasts rather than keratinocytes may be an important shared target of pathogenesis for BDD treponemes.
authors.affiliation: Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK. Electronic address: evansnj@liverpool.ac.uk.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Evans
authors.affiliation: Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Brown
authors.affiliation: Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Scholey
authors.affiliation: School of Veterinary Science, University of Liverpool, Leahurst, Neston CH64 7TE, UK.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Murray
authors.affiliation: School of Environment & Life Sciences, University of Salford, Salford M5 4WT, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Birtles
authors.affiliation: Department of Medical Microbiology, University of Liverpool, Liverpool L69 3GA, UK.
authors.forename: C Anthony
authors.initials: CA
authors.lastname: Hart
authors.affiliation: Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK.
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Carter
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology; D002478:Cells, Cultured; D003872:Dermatitis / Q000382:microbiology / Q000662:veterinary*; D005347:Fibroblasts / Q000378:metabolism / Q000382:microbiology*; D005528:Foot; D005786:Gene Expression Regulation; D007249:Inflammation / Q000378:metabolism*; D015603:Keratinocytes / Q000378:metabolism / Q000382:microbiology*; D012867:Skin / Q000166:cytology; D014208:Treponema / Q000502:physiology*; D014211:Treponemal Infections / Q000382:microbiology / Q000662:veterinary
keywords: Bovine digital dermatitis; Inflammatory response; Spirochetes; Treponema; qRT-PCR