HIF-1α hampers dendritic cell function and Th1 generation during chronic visceral leishmaniasis

Akil Hammami (1) , Belma Melda Abidin (1) , Krista Heinonen (1) , Simona Stäger (1)

1 INRS-IAF - Institut Armand Frappier

Inflammation, although responsible for controlling infection, is often associated with the pathogenesis of chronic diseases. Leishmania donovani, the causative agent of visceral leishmaniasis, induces a strong inflammatory response that leads to splenomegaly and ultimately immune suppression. Inflamed tissues are typically characterized by low levels of oxygen, a microenvironment that triggers the hypoxia-inducible transcription factor 1α (HIF-1α). Although HIF-1α plays an integral role in dendritic cell function, its involvement in the generation of protective Th1 responses against Leishmania has not yet been studied. Here we demonstrate that HIF-1α inhibits IL-12 production in dendritic cells, limiting therefore Th1 cell development. Indeed, depletion of HIF-1α in CD11c+ cells resulted in higher and sustained expression of IL-12 and complete abrogation of IL-10. Moreover, CD11c-specific HIF-1α-deficient mice showed higher frequencies of IFN-γ-producing CD4 T cells in the spleen and bone marrow and, consequently, a significantly reduced parasite burden in both organs. Taken together, our results suggest that HIF-1α expression in dendritic cells largely contributes to the establishment of persistent Leishmania infection and may therefore represent a possible therapeutic target.

Domaines: Sciences du Vivant [q-bio]

Akil Hammami, Belma Melda Abidin, Krista Heinonen, Simona Stäger. HIF-1α hampers dendritic cell function and Th1 generation during chronic visceral leishmaniasis. Scientific Reports, 2018, 8 (1), pp.3500. ⟨10.1038/s41598-018-21891-z⟩. ⟨pasteur-01855947⟩