Immunopathological Changes in the Brain of Immunosuppressed Mice Experimentally Infected with <I>Toxocara canis</I>

Abstract

Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection.

Mesenchymal stem cells combined with albendazole as a novel therapeutic approach for experimental neurotoxocariasis

“…In contrary to our study, Liao et al (2008) and Eid et al (2015) found no inflammatory infiltration or evident pathological changes in brain sections of experimentally infected immunosuppressed mice with T. canis despite the presence of numerous larvae in the brain. They attributed their results for the immune evasion of T. canis larvae or as a protective measure operated by the brain tissues to reduce inflammation.…”

Assessment of Neuroinflammatory and Neurodegenerative Alterations in the Brain in a Mouse Model of Visceral Larva Migrans

“…The absence of inflammatory cell infiltration in the brains of T. canis infected mice that had been detected in the present work is confirmative to the findings of Liao et al (2008), Eid et al (2015) and Chou et al…”

Glial Fibrillary Acidic Protein and Ionized Calcium-Binding Adapter Molecule 1 Immunostaining Score for the Central Nervous System of Horses With Non-suppurative Encephalitis and Encephalopathies

“…In moderate astrogliosis (grade 2), there were 40 to 100 GFAP+ cells/×200 magnification, accompanied by a more prominent cellular hypertrophy, and astrocytic processes overlapped. With this configuration, suggested parasitic infections like those displayed by horses 1, 9, 18, 19, 20, and 22 are supported by the findings demonstrated in mice experimentally infected with Toxocara canis (47,48) and pigs with neurocysticercosis (49). On the other hand, Lemos and Alessi (28) found that astrocytes from horses suffering from leucoencephalomalacia displayed morphological alterations compatible with our grade 2, but with fewer GFAP+ cells.…”