Use of Tissue-Specific MicroRNA to Control Pathology of Wild-Type Adenovirus without Attenuation of Its Ability to Kill Cancer Cells

PLoS Pathogens

Hannah H. Chen¹  Fionnadh Carroll¹  Miriam Bazan-Peregrino¹  Ryan Cawood¹  Leonard W. Seymour¹  Nico van Rooijen² 

[1] Department of Clinical Pharmacology, University of Oxford, Oxford, United Kingdom;Department of Molecular Cell Biology, Vrije Universiteit, Amsterdam, The Netherlands

关键词: MicroRNAs;    Viral replication;    Adenoviruses;    Luciferase;    Cell binding;    Plasmid construction;    Mammalian genomics;    Toxicity;   

DOI  :  10.1371/journal.ppat.1000440

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Replicating viruses have broad applications in biomedicine, notably in cancer virotherapy and in the design of attenuated vaccines; however, uncontrolled virus replication in vulnerable tissues can give pathology and often restricts the use of potent strains. Increased knowledge of tissue-selective microRNA expression now affords the possibility of engineering replicating viruses that are attenuated at the RNA level in sites of potential pathology, but retain wild-type replication activity at sites not expressing the relevant microRNA. To assess the usefulness of this approach for the DNA virus adenovirus, we have engineered a hepatocyte-safe wild-type adenovirus 5 (Ad5), which normally mediates significant toxicity and is potentially lethal in mice. To do this, we have included binding sites for hepatocyte-selective microRNA mir-122 within the 3′ UTR of the E1A transcription cassette. Imaging versions of these viruses, produced by fusing E1A with luciferase, showed that inclusion of mir-122 binding sites caused up to 80-fold decreased hepatic expression of E1A following intravenous delivery to mice. Animals administered a ten-times lethal dose of wild-type Ad5 (5×1010 viral particles/mouse) showed substantial hepatic genome replication and extensive liver pathology, while inclusion of 4 microRNA binding sites decreased replication 50-fold and virtually abrogated liver toxicity. This modified wild-type virus retained full activity within cancer cells and provided a potent, liver-safe oncolytic virus. In addition to providing many potent new viruses for cancer virotherapy, microRNA control of virus replication should provide a new strategy for designing safe attenuated vaccines applied across a broad range of viral diseases.

【 授权许可】

CC BY