title: An adenoviral vector-based expression and delivery system for the inhibition of wild-type adenovirus replication by artificial microRNAs.
abstract: Human adenoviruses are rarely associated with life-threatening infections in healthy individuals. However, immunocompromised patients, and particularly allogeneic hematopoietic stem cell transplant recipients, are at high risk of developing disseminated and potentially fatal disease. The efficacy of commonly used drugs to treat adenovirus infections (i.e., cidofovir in most cases) is limited, and alternative treatment options are needed. Artificial microRNAs (amiRNAs) are a class of synthetic RNAs resembling cellular miRNAs, and, similar to their natural relatives, can mediate the knockdown of endogenous gene expression. This process, termed RNA interference, can be harnessed to target and potentially silence both cellular and viral genes. In this study, we designed amiRNAs directed against adenoviral E1A, DNA polymerase, and preterminal protein (pTP) mRNAs in order to inhibit adenoviral replication in vitro. For the expression of amiRNA-encoding sequences, we utilized replication-deficient adenoviral vectors. In cells transduced with the recombinant vectors and infected with the wild-type (wt) adenovirus, one particular amiRNA that was directed against the pTP mRNA was capable of decreasing the output of infectious wt virus progeny by 2.6 orders of magnitude. This inhibition rate could be achieved by concatemerizing amiRNA-encoding sequences to allow for high intracellular amiRNA concentrations. Because superinfecting wt virus induces the replication and amplification of the recombinant adenoviral vector, amiRNA concentrations were increased in cells infected with wt adenovirus. Furthermore, a combination of amiRNA expression and treatment of infected cells with cidofovir resulted in additive effects that manifested as a total reduction of infectious virus progeny by greater than 3 orders of magnitude.
authors.affiliation: Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Department of Pediatrics, Medical University of Vienna, Austria.
authors.forename: Mirza
authors.initials: M
authors.lastname: Ibrišimović
authors.forename: Doris
authors.initials: D
authors.lastname: Kneidinger
authors.forename: Thomas
authors.initials: T
authors.lastname: Lion
authors.forename: Reinhard
authors.initials: R
authors.lastname: Klein
mesh_terms: D000256:Adenoviridae / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D000998:Antiviral Agents / Q000378:metabolism*; D001688:Biological Products / Q000378:metabolism*; D002460:Cell Line; D000077404:Cidofovir; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D004357:Drug Synergism; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D063065:Organophosphonates / Q000378:metabolism; D034622:RNA Interference; D019562:Viral Load; D014764:Viral Proteins / Q000037:antagonists & inhibitors; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D001688:Biological Products; D035683:MicroRNAs; D063065:Organophosphonates; D014764:Viral Proteins; D003596:Cytosine; D000077404:Cidofovir