DNA Methylation in macrophages infected with Leishmania spp. in different culture conditions.

Leishmania modulate the host cell epigenome, including DNA methylation. This work aimed to explore the DNA methylation pattern in infected macrophages with L. (Viannia) braziliensis, L. (Leishmania) amazonensis and L. (L.) infantum. We performed a genome-wide methylation analysis in macrophages, cultured in presence/absence of interleukin 6 (IL-6) and infected with the three species for a period of 72hs. Upon 72hs infection, sample groups of L. (V.) braziliensis - and L. (L.) infantum-infected macrophages were treated with Glucantime and Amphotericin B for 48hs, respectively. Uninfected macrophages and macrophages treated with heat-killed Leishmania were included as controls. Several CpG islands alterations were identified upon infection and among species. The methylome analysis showed that L. (L.) amazonensis and L. (L.) infantum clustered together separately from L. (V.) braziliensis. The identified alterations were mainly associated with cytoskeleton organization. We also detected that the DNA methylation pattern of ten, six and eight CGIs for each aforementioned species slightly changed in a culture environment with IL-6, whereas treatment led to distinct DNA methylation profiles respect to untreated samples. Interestingly, some altered CGIs showed a re-establishment towards the control methylation pattern in L. (L.) infantum (69%, 11 out of 16) and L. (V.) braziliensis (36%, 4 out of 11). The identified alterations suggest a species-specific parasite/host interaction probably leading to gene expression regulation. The discovery of these methylation alterations addresses further functional studies and suggests them as potential therapeutic targets.