The effect of β-tubulin-specific antisense oligonucleotide encapsulated in different cationic liposomes on the supression of intracellular L. Donovani parasites in vitro

Abstract

An antisense oligonucleotide (20mer) targeted to the parasite β-tubulin gene and encapsulated in cationic liposomes, was used to test its antileishmanial activity in vitro. Cationic liposomes containing dioleyl trimethyl ammonium propane (DOTAP) were found to have higher antileishmanial activity (88% at 4µM oligonucleotide) compared to two other liposomes with stearyl amine (SA) and cetyl trimethyl ammonium bromide (CTAB) as cations. Dot-blot experiments were performed to analyse the expression of β-tubulin mRNA using β-tubulin-specific radiolabelled DNA as a probe. When compared with their respective controls, β-tubulin-specific gene expression was found to be diminished by treatment with a specific antisense oligonuclotide encapsulated in cationic liposomes (CTAB: DOPE) in a concentration-dependent manner. These experiments show that antisense oligonucleotides targeted to the β-tubulin gene of Leishmania donovani inhibit β-tubulin synthesis leading to the arrest of multiplication of intracellular parasites.