Taenia taeniaeformis in rat favors protracted skin lesions caused by Sporothrix schenckii infection: Dectin-1 and IL-17 are dispensable for clearance of this fungus.

Abstract

We occasionally found that cestode Taenia taeniaeformis in rats favored Sporothrix schenckii infection and survival, causing protracted cutaneous lesions. In this study, we compared the pathology and cytokines profile of rats co-infected with the two pathogens and infected with S. schenckii alone to explore underlying mechanisms. In the co-infection group, there was high expression of β-glucan receptor Dectin-1 in the cutaneous lesions and no multinucleated giant cells, but in the S. schenckii infection group the opposite was observed. Cytokines profiles demonstrated an expected finding that IL-4, commonly expressed in helminth and fungus infection, is undetectable in the two infection groups. In the single fungal infection group, cytokines IFN-γ, IL-10 and IL-17 kept increasing in the first few weeks of infection to a peak which was followed by gradual decrease. This study showed that Dectin-1 and IL-17, which were believed to be the major anti-fungus mechanisms, are Th2 independent and dispensable for clearance of S. schenckii infection, suggesting that S. schenckii has a different molecular recognition pattern and evokes anti-infection mechanisms other than Dectin-1 and IL-17.