Ehrlichia canis (Jaboticabal strain) induces the expression of TNF-α in leukocytes and splenocytes of experimentally infected dogs

Abstract

<jats:p>Canine ehrlichiosis is caused by the bacterium Ehrlichia canis and is characterized by a systemic febrile disease of unknown pathogenesis. This study evaluated the expression of cytokines TNF-α, IL-10, IFN-γ, in splenic cells and blood leukocytes during the acute phase of ehrlichiosis and after treatment with doxycycline hyclate in dogs experimentally infected with the E. canis Jaboticabal strain. The study results showed a significant expression of TNF-α 18 days post-inoculation, reducing by approximately 70% after treatment. There was a unique peak of expression of IL-10 and IFN-γ 18 and 30 days post-inoculation, respectively. This study suggests that TNF-α plays a role in the pathogenesis of the acute phase of canine ehrlichiosis and that treatment with doxycycline hyclate reduces the systemic effects of this cytokine, possibly by reducing or eliminating parasitemia.</jats:p>

Increased Cytokine and Nitric Oxide Levels in Serum of Dogs Experimentally Infected with Rangelia vitalii

“…A high expression of TNF-α was found in dogs experimentally infected with Ehrlichia canis [31]. Furthermore, TNF-α also played a role in controlling bacterial number because TNF-α receptor-knockout mice were highly susceptible in this infection [32].…”

Hemorheological Evaluation and Cytokine Production in Dogs Naturally Infected with Anaplasmataceae

“…One study showed that dogs experimentally infected with E. canis had elevated TNF-α production by splenocytes and leukocytes during acute CME, followed by high levels of IL-10 for both cell lines and, finally, only the leukocytes showed IFN-γ production in small scale [70]. TNF-α production at high levels in the experimental infection with E. canis was also verified by Rikihisa and Tajima [5].…”

“…Serum IL-10 levels showed a difference between the studied groups [ Table 6], being relevant the increase of its concentration in dogs infected by Anaplasmataceae bacteria. Studies by Faria et al [70] demonstrated that experimentally infected E. canis infected lymphocytes and splenocytes have high IL-10 and low IFN-γ production, indicating modulation to a Th2-like profile, as IL-10 negatively modulates IFN-γ production.…”

“…During the acute phase of CME, there is an elevation of inflammatory cytokines linked to the immune response, such as TNF-α, IL-10, and IFN-γ [70]. However, Lima et al [71] reported in their work that TNF-α and IL-10 are not associated with early-stage clinical signs of CME.…”

Serum DHEA-S increases in dogs naturally infected with Ehrlichia canis

“…Death may occur due to both its associated hematological alterations and other consequent factors, related to the well-known immune-inflammatory responses (Faria et al, 2011;Kim and Rikihisa, 2002;Tajima and Rikihisa, 2005;Unver et al, 2006) and possibly to hormonal responses (Kumar et al, 2006), which explain the disease's multifactorial catabolic effects (Varshney et al, 2003).…”