Impact ofParacoccidioides brasiliensisCoinfection on the Evolution ofSchistosoma mansoni-Induced Granulomatous Liver Injury in Mice

Abstract

The pathogensSchistosoma mansoniandParacoccidioides brasiliensisshare common geographic areas, determining infectious diseases with high mortality rates worldwide.Histopathological and immunological changes induced by each pathogen are well understood; however, the host responses toS. mansoniandP. brasiliensiscoinfection are still unknown. Thus, we investigated liver damage and cytokines production in a murine model acutely and chronically coinfected with these pathogens. Fourty male Swiss mice were infected withS. mansoniandP. brasiliensisalone or coinfected. The animals were euthanized with 50 (acute infection) and 120 (chronic infection) days of infection. All infected animals exhibited liver inflammation. Intense granulomatous inflammation was detected in animals infected withS. mansonialone and those coinfected. Productive and involutive granulomas were clearly observed in acute and chronic infections, respectively. Granuloma size was reduced in the acute phase and increased in the chronic phase ofS. mansoniandP. brasiliensiscoinfection, compared with animals infected only withS. mansoni. In the chronic phase of infection, the granulomatous inflammation in coinfected animals was characterized by intense neutrophils accumulation and reduced eosinophils number. IFN-γ, IL-2, IL-4, and IL-5 circulating levels were increased in all infected groups. Coinfected animals presented attenuated IFN-γand IL-4 production in the acute and chronic infections. Taken together, our findings indicate that coinfected animals exhibited a differential modulation of granulomatous inflammation during the acute and chronic phases of infection, which was potentially associated with a divergent profile of cytokines production and migration of neutrophils and eosinophils in response toS. mansoniandP. brasiliensisantigenic stimulation.