MicroRNAs Expression Induces Apoptosis of Macrophages in Response to Leishmania major (MRHO/IR/75/ER): An In- Vitro and In-Vivo Study

Background: we aimed to investigate the effect of mir-15a mimic and inhibitor of mir-155 ex-pression on apoptosis induction in macrophages infected with iranian strain of leishmania major in-vitro and in-vivo. methods: raw 264.7 cells were infected with l. major promastigotes (mrho/ir/75/er), and then were treated with mirnas. for in-vivo experiment, balb/c mice were inoculated with l. major promastigotes, and then they were treated with mirnas. for evaluation of mirna thera-peutic effect, in-vitro and in-vivo studies were performed using quantitative real-time pcr, flow cytometry, lesion size measurement, and limiting dilution assay (lda). this study was performed in shahid beheshti university of medical sciences in 2019. results: in-vitro results of flow cytometry showed that using mir-15a mimic, mir-155 inhibitor or both of them increased apoptosis of macrophages. in in-vivo, size of lesion increased during experiment in control groups (p<0.05) while application of both mir-155 inhibitor and mir-15a mimic inhibited the increase in the size of lesions within 6 wk of experiment (p=0.85). lda results showed that microrna therapy could significantly decrease parasite load in mimic or inhibitor receiving groups compared to the control group (p<0.05). conclusion: mir-155 inhibitor and mir-15a mimic in l. major infected macrophages can induce apoptosis and reduce parasite burden. therefore, mirna-based therapy can be proposed as new treatment for cutaneous leishmaniasis.