Poster abstracts

Poster number 61 submitted by Chad Schwartz

Targeted delivery of anti-coxsackievirus siRNAs using ligand-conjugated pRNA nanoparticles

Huifang M. Zhang, Yue Su, Ji Yuan, Travis Lim (Department of Pathology and Laboratory Medicine, University of British Columbia, Canada), Chad Schwarct (Department of Biomedical Engineering, University of Cincinnati), Songchuan Guo, Jing Liu, Peixuan Guo (Department of Biomedical Engineering, University of Cincinnati), Decheng Yang (Department of Pathology and Laboratory Medicine, University of British Columbia, Canada)

Abstract:
Coxsackievirus B3 (CVB3) is a common pathogen of myocarditis. We previously synthesized a siRNA targeting the CVB3 protease 2A (siRNA/2A) gene and achieved reduction of CVB3 replication by 92% in vitro. However, like other drugs under development, CVB3 siRNA faces a major challenge of targeted delivery. In this study, we investigated a novel approach to deliver CVB3 siRNAs to a specific cell population (e.g. HeLa cells containing folate receptor) using receptor ligand (folate)-linked packaging RNA (pRNA) from bacterial phage phi29. pRNA monomers can spontaneously form dimers and multimers under optimal conditions by base-pairing between their stem loops. By covalently linking a fluorescence-tag to folate, we delivered the conjugate specifically to HeLa cells without the need of transfection. We further demonstrated that pRNA covalently conjugated to siRNA/2A achieved an equivalent antiviral effect to that of the siRNA/2A alone. Finally, the drug targeted delivery was further evaluated by using pRNA monomers or dimers, which carried both the siRNA/2A and folate ligand and demonstrated that both of them strongly inhibited CVB3 replication. These data indicate that pRNA as a siRNA carrier can specifically deliver the drug to target cells via its ligand and specific receptor interaction and inhibit virus replication effectively.

Keywords: Bacteriophage phi29, pRNA, gene delivery