Evaluation of Cytokine Messenger RNA Expression in Peripheral Blood Mononuclear Cells from Dogs with Canine Demodicosis.

Abstract

ABSTRACT. Using RT-PCR and semi-quantitative PCR, mRNA expression for canine interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-5, IL-10, tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β in peripheral blood mononuclear cells (PBMCs) was examined in dogs with or without demodicosis. mRNA expression for IFN-γ as well as TNF-α in dogs with demodicosis (localized (LD) and generalized (GD)) was slightly lower than those in dogs without demodicosis (healthy controls). Expression of IL-5 mRNA in dogs with demodicosis was higher than that in control dogs, but there were no significant differences in IL-4 and IL-10 mRNA expression levels among the three groups. On the other hand, expression levels of TGF-β mRNA in dogs with GD were higher than those in control dogs and dogs with LD. The expression levels of IL-5 and TGF-β mRNA decreased in all three dogs with GD which showed resolution of the clinical signs. Taken together, these results suggest that the Th2-like response in PBMCs from dogs with demodicosis is up-regulated, and that subsequent increased expression of IL-5 and TGF-β mRNA in dogs with GD is reversible after treatment. Therefore, these cytokines, particularly IL-5, might be a useful clinical index of the clinical course in demodicosis. Also, increased TGF-β mRNA expression might be a key factor for revealing the difference in the mechanism of onset between LD and GD.

Demodex canis targets TLRs to evade host immunity and induce canine demodicosis

“…Recently, Yarim et al have demonstrated marked elevation in circulatory transforming growth factor beta (TGF‐β) 1 concentrations in dogs with GD compared to the healthy ones. TGF‐β mRNA expression in peripheral blood mononuclear cells was higher in dogs with LD than healthy ones, and the key role of TGF‐β in the differentiation of LD and GD was suggested . It has also been demonstrated that dogs with GD have a lower CD4+ /CD8+ T cell ratio than dogs having LD .…”

Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil. V. Cytokine concentrations in experimentally infected Wistar rats

“…This could indicate an early switch to a TH2-type of help, as IL-4 is a key factor for the differentiation of precursor helper cells into TH2 subsets. Up-regulation of the TH2-type of help has been observed in canine demodicosis, a mite infestation of the skin similar to scabies (Tani et al 2002). An early switch towards a predominant TH2-type of help would explain why we could not find an increased serum concentration of IFN-c in the infected animals (Fig.…”

A Comparative Analysis of Immunorestoration and Recovery with Conventional and Immunotherapeutic Protocols in Canine Generalized Demodicosis: A Newer Insight of Immunotherapeutic Efficacy of T11TS

“…Ill animals was also evident by the incorporation of dense colored granules (NBT dye granules) in the cytoplasm of the phagocytic cells. A recent study demonstrated that Th2-type response is upregulated in dogs having generalized demodicosis with subsequently increased expression of IL-5 and TGFp mRNA in peripheral blood mononuclear cells (PBMGs), but no significant differences were observed in IL-4 and IL-10 mRNA production (Tani et al, 2002). Increased M(|) phagocytosis in diseased condition may result from an alternative activation of Mcj) by the Th2 cytokines e.g., IL-13 (Gordon, 2003).…”

“…Increased level of TGFp (potent immunosuppressive cytokine) and other immunosuppressive factors such as prostaglandin fi-om the activated Mcj) during diseased condition (Tani et al, 2002;Taveme and Bradley, 1998) can be accounted for the immunosuppression in generalized demodicosis. Parasites like D. canis secrete large amount of antigens which in turn cause high phagocytic activity and consequent overloading of Mcj) resulting in its impaired antigen presenting capacity (Taveme and Bradley, 1998).…”