Recombinant murine IL-12 promotes a protective Th1/cellular response in Mongolian gerbils infected with Sporothrix schenckii.

Sporotrichosis is a cutaneous fungal infection caused by Sporothrix schenckii. It is known to be mainly contained by Th1 responses. As IL-12 is crucial for Th1 response, we investigated if treatment with recombinant murine IL-12 (rmIL-12) promoted Th1 immunity and/or clinical improvement in an experimental sporotrichosis gerbil model. Gerbils were inoculated with S. schenckii in the footpad and treated with rmIL-12. Seven days post infection there was a significant increase in macrophage phagocytosis and oxidative burst, and in delayed-type hypersensitivity (DTH) reaction in rmIL-12 treated gerbils, as well as a ∼10-fold increase of serum IFN-gamma and a decrease of IL-4 and IL-10. Moreover, rmIL-12 substantially decreased (∼70%) S. schenckii burden in liver and spleen and improved the clinical outcome preventing footpad ulcer and tail nodules observed in untreated gerbils. Our study demonstrates that rmIL-12 promotes Th1 immune response against S. schenckii favouring its clearance and preventing clinical symptoms.