Transient Down-Regulation of Nucleoside Transporter 3 Gene Expression as a Drug Target in Leishmania major Using Antisense RNA Technology.

BACKGROUND: This study was aimed to silencing the Nucleoside transporter 3 (NT3) permease nucleobases involved in the salvage pathway of Leishmania in order to disrupt purine nucleotide uptake in the parasite and consequently, destruction of the parasite. METHODS: Overall, 502 bp fragment of the NT3 gene sequence was designed to produce an antisense transcript upon entry of the vector into the parasite. The NT3 construct was transfected into L. major promastigotes and NT3 gene expression was studied in vivo and in vitro conditions. RESULTS: Relative expression NT3 gene in transgenic Leishmania was decreased in tenth day. The percentages and the number of amastigotes infected macrophages with transgenic L. major were less than infected macrophages with wild-type strain. Our results in two groups of BALB/c female mice (wild-type strain and mutant, n=4 each group) were showed that size and number of ulcers in BALB/c mice infected with transgenic Leishmania promastigotes were less than the BALB/c mice infected with wild-type parasites. CONCLUSION: The results indicate the use of antisense RNA reduces of NT3 gene expression in L. major. More studies are required to obtain a new approach for treating Leishmania infection. KEYWORDS: Antisense RNA; Drug target; Gene expression; Leishmania major; Nucleoside transporter 3 gen