HIF-alpha signaling mediates the macrophage inflammatory response during Leishmania majorinfection

Cutaneous leishmaniasis (CL) is responsible for a significant burden of the global incidence of neglected tropical diseases, with 12 million people currently infected with Leishmania parasites. CL contains a spectrum of disease manifestations, ranging from self-healing skin lesions to permanent disfigurations. Currently there is no vaccine available, and many patients are refractory to treatment, emphasizing the need for new therapeutic targets. Previous work has demonstrated the necessity of macrophage HIF-alpha-mediated lymphangiogenesis to achieve efficient wound resolution during murine L. major infection. Here we investigate the role of macrophage HIF-alpha signaling separate from lymphangiogenesis, employing RNA-Seq transcriptome analysis on macrophages with intact or compromised HIF-alpha signaling, LysMCreARNTf/+ or LysMCreARNTf/f respectively, during L. major infection and under pro-inflammatory stimulus. We report that L. major infection alone is enough to induce HIF-alpha dependent transcriptomic changes while infection with L. major and pro-inflammatory stimuli administration instigates transcriptomic changes both dependent and independent of HIF-alpha signaling. Additionally, by coupling transcriptomic analysis with several pathway analyses, we found during L. major infection and in a pro-inflammatory environment, HIF-alpha suppresses pathways involved in protein translation such as the ribosome pathway and EIF2 signaling. Together this work supports infection with L. major induces a HIF-alpha transcriptomic program, but only in a pro-inflammatory environment does HIF-alpha suppress protein translation. Overall design: Bulk RNA-Seq of bone marrow derived macrophages that are either from mice with intact myeloid HIF-alpha signaling (LysMCre ARNT f/+) or deleted myeloid HIF-alpha signaling (LysMCre ARNT f/f). Macrophages from both strains of mice were 1) cultured in media alone, 2) infection with Leishmania major metacyclic promastigote parasites, or 3) infected with L. major parasites and LPS plus IFNg for 8 hours