Formation of adenovirus DNA replication compartments.

Adenoviruses induce an extensive reorganization of the host cell nucleus during replication. Such a process results in the assembly of viral and cellular macromolecules into nuclear structures called adenovirus replication compartments (AdRCs), which function as platforms for viral DNA replication and gene expression. AdRCs co-opt host proteins and cellular pathways that restrict viral replication, suggesting that the mechanisms that control AdRC formation and function are essential for viral replication and lay at the basis of virus-host interactions. Here, we review the hallmarks of AdRCs and recent progress in our understanding of the formation, composition, and function of AdRCs. Furthermore, we discuss how AdRCs facilitate the interplay between viral and cellular machineries and hijack cellular functions to promote viral genome replication and expression.

1-(4-Phenoxybenzyl) 5-Aminouracil Derivatives and Their Analogues - Novel Inhibitors of Human Adenovirus Replication.

Adenovirus infections are characterized by widespread distribution. The lack of causal therapy, which is effective in treating this group of diseases, explains the need for new therapeutic drugs. Notably, anti-adenoviral activity of [4-(phenoxy)benzyl]-5-(phenylamino)-6-azauracil, 1-[4-(phenoxy)benzyl]-5-(morpholino) uracil, 1-[4-(4-chlorophenoxy)benzyl]-5-(morpholino) uracil, and 1-[4-(4-fluorophenoxy)-benzyl]-5-(morpholino) uracil was observed.

Loss of Cyclin-Dependent Kinase Inhibitor Alters Oncolytic Adenovirus Replication and Promotes More Efficient Virus Production.

We elucidate the role of p21/Waf-1, a cyclin-dependent kinase inhibitor, on the oncolytic infection and replication cycle of adenovirus by studying both mRNA and adenoviral proteins expression. We found that infection in the absence of p21 causes a significant increase in adenoviral genomes and late gene expression. Similarly, the oncolytic adenoviral infected p21−/− cells have earlier formation of replication foci and robust replication kinetics that were not observed in the wild type p21/Waf-1 intact cells. These findings suggest a culmination that the presence of intact p21 in host cells causes defects in the oncolytic viral life cycle which results in the production of immature and noninfectious particles.

Expression of human CD46 and trans-complementation by murine adenovirus 1 fails to allow productive infection by a group B oncolytic adenovirus in murine cancer cells.

BACKGROUND: Oncolytic viruses are currently experiencing accelerated development in several laboratories worldwide, with some forty-seven clinical trials currently recruiting. Many oncolytic viruses combine targeted cytotoxicity to cancer cells with a proinflammatory cell lysis. Due to their additional potential to express immunomodulatory transgenes, they are also often known as oncolytic viral vaccines. However, several types of oncolytic viruses are human-specific and the lack of suitable immune-competent animal models complicates biologically relevant evaluation of their vaccine potential. This is a particular challenge for group B adenoviruses, which fail to infect even those immunocompetent animal model systems identified as semi-permissive for type 5 adenovirus. Here, we aim to develop a murine cell line capable of supporting replication of a group B oncolytic adenovirus, enadenotucirev (EnAd), for incorporation into a syngeneic immunocompetent animal model to explore the oncolytic vaccine potential of group B oncolytic viruses. METHODS: Transgenic murine cell lines were infected with EnAd expressing GFP transgene under replication-independent or -dependent promoters. Virus mRNA expression, genome replication, and late protein expression were determined by qRT-PCR, qPCR, and immunoblotting, respectively. We also use Balb/c immune-competent mice to determine the tumourogenicity and infectivity of transgenic murine cell lines. RESULTS: Our results show that a broad range of human carcinoma cells will support EnAd replication, but not murine carcinoma cells. Murine cells can be readily modified to express surface human CD46, one of the receptors for group B adenoviruses, allowing receptor-mediated uptake of EnAd particles into the murine cells and expression of CMV promoter-driven transgenes. Although the early E1A mRNA was expressed in murine cells at levels similar to human cells, adenovirus E2B and Fibre mRNA expression levels were hampered and few virus genomes were produced. Unlike previous reports on group C adenoviruses, trans-complementation of group B adenoviruses by co-infection with mouse adenovirus 1 did not rescue replication. A panel of group B adenoviruses expressing individual mouse adenovirus 1 genes were also unable to rescue EnAd replication. CONCLUSION: Together, these results indicate that there may be major differences in the early stages of replication of group C and B adenoviruses in murine cells, and that the block to the life cycle of B adenoviruses in murine cells occurs in the early stage of virus replication, perhaps reflecting poor activity of Ad11p E1A in murine cells.