Targeting Macrophage Histone H3 Modification as a Leishmania Strategy to Dampen the NF-κB/NLRP3-Mediated Inflammatory Response.
Lecoeur H, Prina E, Rosazza T, Kokou K, N'Diaye P, Aulner N, Varet H, Bussotti G, Xing Y, Milon G, Weil R, Meng G, Späth GF
Aberrant macrophage activation during intracellular infection generates immunopathologies that can cause severe human morbidity. A better understanding of immune subversion strategies and macrophage phenotypic and functional responses is necessary to design host-directed intervention strategies. Here, we uncover a fine-tuned transcriptional response that is induced in primary and lesional macrophages infected by the parasite Leishmania amazonensis and dampens NF-κB and NLRP3 inflammasome activation. Subversion is amastigote-specific and characterized by a decreased expression of activating and increased expression of de-activating components of these pro-inflammatory pathways, thus revealing a regulatory dichotomy that abrogates the anti-microbial response. Changes in transcript abundance correlate with histone H3K9/14 hypoacetylation and H3K4 hypo-trimethylation in infected primary and lesional macrophages at promoters of NF-κB-related, pro-inflammatory genes. Our results reveal a Leishmania immune subversion strategy targeting host cell epigenetic regulation to establish conditions beneficial for parasite survival and open avenues for host-directed, anti-microbial drug discovery.
