Open AccessAntisense phosphorothioate oligonucleotides: selective killing of the intracellular parasite Leishmania amazonensis.
Author(s) -
Claude Ramazeilles,
Rakesh K. Mishra,
Serge Moreau,
Emanuelle Pascolo,
JeanJacques Toulmé
Publication year - 1994
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.91.17.7859
Subject(s) - oligonucleotide , biology , leishmania , amastigote , intracellular , microbiology and biotechnology , kinetoplastida , leishmania mexicana , sense (electronics) , exon , rna , parasite hosting , biochemistry , gene , chemistry , immunology , protozoal disease , world wide web , computer science , malaria
We targeted the mini-exon sequence, present at the 5' end of every mRNA of the protozoan parasite Leishmania amazonensis, by phosphorothioate oligonucleotides. A complementary 16-mer (16PS) was able to kill amastigotes--the intracellular stage of the parasite--in murine macrophages in culture. After 24 hr of incubation with 10 microM 16PS, about 30% infected macrophages were cured. The oligomer 16PS acted through antisense hybridization in a sequence-dependent way; no effect on parasites was observed with noncomplementary phosphorothioate oligonucleotides. The antisense oligonucleotide 16PS was a selective killer of the protozoans without any detrimental effect to the host macrophage. Using 16PS linked to a palmitate chain, which enabled it to complex with low density lipoproteins, improved the leishmanicidal efficiency on intracellular amastigotes, probably due to increased endocytosis. Phosphorothioate oligonucleotides complementary to the intron part of the mini-exon pre-RNA were also effective, suggesting that antisense oligomers could prevent trans-splicing in these parasites.