Expression of Toll-Like Receptors (TLR2 and TLR4) in the Eyes of Mice with Disseminated Acanthamoebiasis

Abstract

Toll-like receptors (TLRs) play a key role in the innate immune response to numerous pathogens, including Acanthamoeba spp. The aim of this study was to determine the expression of TLR2 and TLR4 in the eyes of mice following intranasal infection with Acanthamoeba spp. in relation to the host’s immunological status. Amoebae used in this study were isolated from the bronchial aspirate of a patient with acute myeloid leukemia (AML) and atypical symptoms of pneumonia. We found statistically significant differences in the expression of TLR2 and TLR4 in the eye of immunocompetent mice at 8, 16, and 24 days after Acanthamoeba spp. infection (dpi) compared to control group. Immunosuppressed mice showed significant differences in the expression of TLR2 at 16 and 24 dpi compared to uninfected animals. Our results indicate that TLR2 and TLR4 are upregulated in the eyes of mice in response to Acanthamoeba spp. We suggest that it is possible for trophozoites to migrate through the optic nerve from the brain to the eyes. The course of disseminated acanthamoebiasis may be influenced by the host’s immunological status, and the observed changes in expression of TLR2 and TLR4 in the host’s organs may indicate the role of these receptors in the pathomechanism of acanthamoebiasis.

Antioxidant defense in the eyes of immunocompetent and immunosuppressed mice infected with Acanthamoeba spp.

“…Our previous study has shown that the infection of an eye may also take place via the migration of trophozoites through the optic nerve from the brain to the eyes [14]. Moreover, we observed an altered expression of Toll-like receptors (TLR) 2 and 4 in the eyes of mice intranasally infected with Acanthamoeba spp.…”

“…In this study, a continuation of our previous study [14], we want to show that the dysregulation of antioxidants is a part of the pathomechanism during acanthamoebiasis. Therefore, we analyzed the activity of enzymatic antioxidants and the concentration of non-enzymatic antioxidant in the eyes of Acanthamoeba-infected immunocompetent and immunocompromised mice.…”

“…The immunosuppression, intranasal inoculation and pathogenic tests followed a previously described method [14]. The mice were sacrificed using sodium pentobarbital (Euthasol vet, FATRO, Raamsdonksveer, The Netherlands) injected intraperitoneally at 2 ml/kg body weight.…”

“…Eye samples for biochemical analysis were stored at − 80 °C and those for histological analyses were stored in 4% buffered formalin solution (Avantor, Gliwice, Poland). As a continuation of our previous research [14], in this study we decided to analyze the activity/concentration of antioxidants in the eyes of the mice as they were too small to analyze ophthalmic tissues separately.…”

“…Moreover, we observed an altered expression of Toll-like receptors (TLR) 2 and 4 in the eyes of mice intranasally infected with Acanthamoeba spp. [14]. It was found that oxidative stress or dysregulation of antioxidants may upregulate the expression of TLR2 and TLR4 [15].…”