transE1 Component Requirements for Maximal Replication of E1-Defective Recombinant Adenovirus

Abstract

Strategies that enable E1-defective recombinant adenoviruses to selectively undergo replication in neoplastic tissue may be useful for future investigations or therapies of malignancies. A growing body of evidence suggests that some molecular alterations commonly associated with malignancies, such as p53 mutations, can modify the specific E1 requirements for replication of human serotype adenoviruses. In the studies reported here, a panel of human non-small cell lung cancer cell lines with previously defined p53 status were characterized for basal interleukin-6 (IL-6) and bcl-2 content because previous studies have indicated both proteins can functionally substitute for the replication requirements provided by native E1 viral proteins. Cell lines were infected with E1-defective adenovirus 5 and simultaneously transfected with different combinations of E1 plasmids, or a bcl-2 expression plasmid, and adenovirus present in the cells was quantified 6 days later. These assays demonstrated that E1A with both 19- and 55-kDa E1B-encoding plasmids were required for maximal adenoviral replication, independent of the varying p53/IL-6/basal bcl-2 phenotypes of the host cell lines. E1A was required for maximal replication enablement, independent of the basal IL-6 content of these cell lines, and exogenous IL-6 also did not obviate the E1A requirement. Interestingly, the bcl-2 expression plasmid did not consistently substitute for the 19-kDa expression plasmid in the context of this replication complementation assay. These results suggest that (1) basal levels of IL-6 greater than that present in these cell lines are necessary for functional replacement of the E1A replication function and (2) bcl-2 does not predictably substitute for the 19-kDa E1B replication function in the context of trans complementation.

Real-time quantitative PCR for enteric adenovirus serotype 40 in environmental waters

“…Ad40, freshly harvested from tissue culture of human embryonic kidney cell 293A (Goldsmith et al 1998), was used in the seeding study. For Ad40 purification, the cells with viral infection were harvested in PBS buffer.…”

In vivo Imaging of Adenovirus Transduction and Enhanced Therapeutic Efficacy of Combination Therapy with Conditionally Replicating Adenovirus and Adenovirus-p27

“…This basic concept of trans-complementation was first reported with the demonstration that transduction with an E1-deleted adenovirus and transfection of plasmid containing E1 (pE1) in a cell induced the production of E1-deleted adenovirus and amplified viral transgene expression (9,10).…”

Trans-complementation of vector replication versus Coxsackie-adenovirus-receptor overexpression to improve transgene expression in poorly permissive cancer cells

“…A completely different strategy to increase the efficiency of adenoviral gene therapy is the enhancement of therapeutic transgene expression by induction of 'replication' of the vector genome. 24 This general strategy has been further developed by coadministration of 13s E1A transcripts 25 or E1A-proteinexpressing plasmids [26][27][28] together with an E1-deleted AdV. It has also been employed for cancer gene therapy by using a restricted replication-competent adenovirus (RRCA) selectively replicating in and lysing p53-deficient tumor cells due to mutations in the E1B-55K protein [29][30][31][32] or by co-administration of RRCA with cytokine 32 or suicide gene 33 -expressing E1-deleted AdV.…”