Innate immune receptors are differentially expressed in mice during experimental Schistosoma mansoni early infection.

Background: The impact of Schistosoma mansoni infection over the immune response and the mechanisms involved in pathogenesis are not yet completely understood.

Objectives: This study aimed to evaluate the expression of innate immune receptors in three distinct mouse lineages (BALB/c, C57BL/6 and Swiss) during experimental S. mansoni infection with LE strain.

Methods: The parasite burden, intestinal tissue oogram and presence of hepatic granulomas were evaluated at 7- and 12-weeks post infection (wpi). The mRNA expression for innate Toll-like receptors, Nod-like receptors, their adaptor molecules, and cytokines were determined at 2, 7 and 12 wpi in the hepatic tissue by real-time quantitative polymerase chain reaction (qPCR).

Findings: Swiss mice showed 100% of survival, had lower parasite burden and intestinal eggs, while infected BALB/c and C57BL/6 presented 80% and 90% of survival, respectively, higher parasite burden and intestinal eggs. The three mouse lineages displayed distinct patterns in the expression of innate immune receptors, their adaptor molecules and cytokines, at 2 and 7 wpi.

Main conclusions: Our results suggest that the pathogenesis of S. mansoni infection is related to a dynamic early activation of innate immunity receptors and cytokines important for the control of developing worms.