IFN-gamma role in granuloma formation in experimental subcutaneous cysticercosis.

Cysticercosis is an infection caused by the metacestode larval stage of Taenia parasites in tissues and elicits a host-parasite reaction in which the immune response may be decisive in the disease development. The aim of this study was to evaluate the role of IFNγ (IFN-gamma) in the experimental model of subcutaneous infection with Taenia crassiceps (T. crassiceps) cysticerci using IFNγ knockout mice. Male C57BL/6 and C57BL/6 KO IFNγ mice 8-12 weeks of age were inoculated with T. crassiceps cysticerci into the subcutaneous tissue of the dorsum. At 7 and 30 (acute phase), 60 and 90 (chronic phase) days post infection, animals from each group had their blood and the subcutaneous tissues collected for serologic and pathological studies. IFNγ and IL-4 were dosed and the histopathological analysis was performed. In the presence of IFNγ there was the establishment of a mixed Th1/Th2 systemic immune profile. This profile also locally induced the granuloma formation which was constituted by cells that played important roles in the parasitary destruction and that were likely associated to the Th1 axis of mixed immune response. On the other hand, the absence of IFNγ appears to favor the parasitary growth which may be related to the development of a systemic Th2 immune response. This profile influenced the granuloma formation with immunoregulatory properties and appears to be important in the collagen synthesis.