Digital dermatitis in cattle is associated with an excessive innate immune response triggered by the keratinocytes

Abstract

BackgroundDigital Dermatitis (DD) is a common disease of dairy cows, the pathogenesis of which is still not clear. This study examined some host responses associated with the typical lesions, in an attempt to further elucidate the pathogenesis of the disease. Twenty four samples representing the 5 different clinical stages of DD (M0-M4) were collected from slaughtered cattle for histopathological and immunological analyses.ResultsSignificant increases in total epidermal thickness were found in M2, M3, and M4 when compared with M0 and M1. M3 samples, when compared with M0 and M1, were characterized by a significant increase in the thickness of the keratin layer. Counts of both eosinophils and neutrophils were at a maximum in the M2 stage and decreased in the M3 and M4 stage. A significant increase in IL8 expression was observed in the M2-M3 stages of the disease and immunohistochemical staining showed the source as keratinocytes, suggesting an important role for keratinocyte-derived IL8 in the pathogenesis of DD.ConclusionResults of the present study point to a strong stimulation of the innate immune response at the level of the keratinocytes throughout most of the clinical stages, and a delayed response of the adaptive immune reaction.

A distinct bacterial dysbiosis associated skin inflammation in ovine footrot

“…This may explain the thickened epidermal layer of ovine interdigital skin observed in histological studies of footrot1. Both cytokines, CXCL8 and IL1β, were highly expressed in sheep with skin pyogranulomas59, in response to inflamed foetal ovine skin60 and also in bovine digital dermatitis lesions in cattle feet54.…”

“…The host immune response was investigated through the mRNA expression of a panel of six inflammatory genes likely to have a role in skin immune responses in sheep and cattle235455. Surprisingly, in the context of foot disease, no differential expression of IL1β, IL6, CXCL8 and IL17 was identified in ID and footrot compared to healthy samples.…”

A novel approach to probe host-pathogen interactions of bovine digital dermatitis, a model of a complex polymicrobial infection

“…This inflammatory skin disease is characterized by focal proliferative to ulcerative dermatitis typically located on the plantar aspect of the hoof [5]. Present treatments include topical antibiotics and footbaths, but DD is difficult to eliminate, and infections are often recurrent [3, 6]. Recently, culture-independent microbial community profiling using 16S rRNA gene analysis revealed a high prevalence of invasive treponemes with genetic heterogeneity in DD lesions [7–11].…”

Anti‐inflammatory and protective effects of 2‐methacryloyloxyethyl phosphorylcholine polymer on oral epithelial cells

“…IL‐8 is known to be produced early in the inflammatory response and has a key role in the recruitment and activity of neutrophils, which are considered major contributors to the tissue damage during inflammatory diseases . The massive increase of IL‐8 is considered to be due not only increase numbers of producing cells, but also an up‐regulation of the expression . Neutrophil extracellular traps (NETs), which are produced by neutrophils to exterminate the microorganisms and have an inflammatory potential, contents are abundant at the site of infection and acute inflammation .…”

“…[7][8][9] The massive increase of IL-8 is considered to be due not only increase numbers of producing cells, but also an up-regulation of the expression. 10 Neutrophil extracellular traps (NETs), which are produced by neutrophils to exterminate the microorganisms and have an inflammatory potential, contents are abundant at the site of infection and acute inflammation. [11][12][13] Recently, NETs have been identified in infected periodontal tissue and a potential role for NETs in periodontal disease pathogenesis was reported.…”