Gene selective mRNA cleavage inhibits the development of Plasmodium falciparum

• Published in: Proceedings of the National Academy of Sciences - PNAS 2012-04, Vol.109 (16), p.6235-6240
• Main Authors: Augagneur, Yoann, Wesolowski, Donna, Tae, Hyun Seop, Altman, Sidney, Ben Mamoun, Choukri
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Antimalarials; Base Sequence; Biological Sciences; Developmental biology; DNA Gyrase - genetics; DNA Gyrase - metabolism; early development; Enzymes; Erythrocytes; Erythrocytes - parasitology; Fluorescein - chemistry; Fluorescence; fluorescence microscopy; Gene Expression Regulation, Developmental - genetics; genes; HeLa Cells; Humans; Malaria; Messenger RNA; Microscopy, Fluorescence; Morpholinos - chemistry; Morpholinos - genetics; Morpholinos - metabolism; Parasites; Peptides; Peptides - chemistry; Plasmodium falciparum; Plasmodium falciparum - genetics; Plasmodium falciparum - growth & development; Plasmodium falciparum - metabolism; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA Cleavage; RNA, Messenger - genetics; RNA, Messenger - metabolism; Schizonts
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1203516109

Unique peptide-morpholino oligomer (PMO) conjugates have been designed to bind and promote the cleavage of specific mRNA as a tool to inhibit gene function and parasite growth. The new conjugates were validated using the P. falciparum gyrase mRNA as a target (PfGyrA). Assays in vitro demonstrated a selective degradation of the PfGyrA mRNA directed by the external guide sequences, which are morpholino oligomers in the conjugates. Fluorescence microscopy revealed that labeled conjugates are delivered into Plasmodium-infected erythrocytes during all intraerythrocytic stages of parasite development. Consistent with the expression of PfGyrA in all stages of parasite development, proliferation assays showed that these conjugates have potent antimalarial activity, blocking early development, maturation, and replication of the parasite. The conjugates were equally effective against drug sensitive and resistant P. falciparum strains. The potency, selectivity, and predicted safety of PMO conjugates make this approach attractive for the development of a unique class of target-specific antimalarials and for large-scale functional analysis of the malarial genome.