Absence of Batf3 results in reduced liver pathology in mice infected with Schistosoma japonicum.

Background: The involvement of CD8 ⁺ T cells in schistosomiasis is being increasingly appreciated, but the underlying mechanism is not well defined.
Results: In this study, we showed that the absence of Batf3 alleviated liver damage in Batf3 ^-/- mice infected with S. japonicum. We found alleviated liver granulomatous inflammation in Batf3 ^-/- mice with schistosomiasis japonica could not be attributed to the difference in schistosome egg or worm burden. The stronger Tc1 cell responses observed in Batf3 ^-/- mice suggested that the deletion of Batf3 resulted in more activation of CD8 ⁺ T cells unexpectedly during the natural infection of schistosomes. We detected a small amount of CD8α ⁺ DCs in the spleen of Batf3 ^-/- mice at 9w post-infection. This small amount of newly generated CD8α ⁺ DCs might contribute to enhanced activation of CD8 ⁺ T cells via cross-presentation and activation which then attenuate hepatic pathological damage found in Batf3 ^-/- mice.
Conclusions: Our study provides evidence that Batf3 is associated with the immunoregulation of the liver granuloma formation, which may confer a new options for schistosomiasis treatment.