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PubMed1985

Molecular epidemiology of adenoviruses: global distribution of adenovirus 7 genome types.

Adenovirus 7 (Ad7) is the adenovirus species that most frequently has been associated with severe illness. Seven distinct genome types of adenovirus 7, Ad7p, Ad7a, Ad7b, Ad7c, Ad7d, Ad7e, and Ad7f, can be identified by using restriction endonucleases BamHI and SmaI. We analyzed the distribution of the different Ad7 genome types among 314 isolates from patients and healthy shedders. The Ad7b and Ad7c genome types accounted for 90% of the isolates from patients and appeared to be mutually exclusive. A shift from Ad7c to Ad7b genome types occurred in 1969 in Europe and in 1975 in Australia. During the last decade, Ad7b genome types predominated in Australia, Europe, and North America. Ad7c was detected in South Africa, Ad7d was detected in China, Ad7e was detected in Brazil, and Ad7f was detected in Australia. The Ad7p and Ad7a genome types dominated among isolates obtained from healthy shedders and appeared scattered through the years and the geographical areas. The prevalence of Ad7 infections is high in Japan as judged by the herd immunity. However, the low percentage (2%) of Ad7 isolates among all adenovirus isolates chiefly from patients, coupled with 30 to 50% antibody prevalence, argues for a high proportion of inapparent infections and, hence, Ad7 strain(s) of low pathogenicity.

Adenoviruses, Human↗
PubMed1991

Identification of two distinct regions within the adenovirus minimal origin of replication that are required for adenovirus type 4 DNA replication in vitro.

The adenovirus type 4 origins of replication are located at each end of the linear, protein-linked viral DNA molecule and consist of the terminal 18 bp of the viral genome. The sequence of the first 8 bp of the viral genome varies among different adenovirus serotypes, but the sequence from bp 9 to 18 is conserved in all human serotypes, suggesting that it may be of critical importance to origin function. Using an in vitro system in which purified fractions or crude extracts of adenovirus type 4-infected HeLa cells can support initiation and elongation on linearized plasmid templates containing cloned origin sequences, we examined the effect of single base changes in positions 9 to 18 of the adenovirus origin on DNA replication in vitro. Changes in positions 12 to 16 have little effect, whereas alterations at positions 9, 10, 11, 17, and 18 all reduce the efficiency of initiation of DNA replication by between 50 and 90%. Our results show that the region from bp 9 to 18 contains two sets of bases essential for DNA replication which are separated by 5 bp in which single base changes can be accommodated. The likely role of the region from bp 9 to 18 as containing the recognition sequence for a DNA-protein interaction essential for viral DNA replication is discussed.

Adenoviruses, Human↗
PubMed2003

Transcription initiation activity of adenovirus left-end sequence in adenovirus vectors with e1 deleted.

We analyzed the transcription initiation activity of the left-end sequence (first 342 bp) of the adenovirus genome in the context of an adenovirus vector with E1 deleted in in vitro and in vivo gene transfer models. While nucleotide sequences 1 to 190 and 1 to 342 showed strong activity in three out of three lung cancer cell lines, nucleotide sequence 1 to 103 showed limited activity in H358, cells which show characteristics of type 2 alveolar cells. In vivo, the transcription initiation activities of nucleotide sequence 1 to 103 in the liver and the lung were minimal, while nucleotide sequences 1 to 190 and 1 to 342 showed strong activity comparable to that of the cytomegalovirus promoter. Further understanding of the transcription initiation activity of the left-end sequence of the adenovirus genome should lead to optimization of adenovirus vectors.

Adenoviridae↗
PubMed2006

Mechanism of increased coxsackie and adenovirus receptor gene expression and adenovirus uptake by phytoestrogen and histone deacetylase inhibitor in human bladder cancer cells and the potential clinical application.

Coxsackie and adenovirus receptor (CAR) is known as a principal receptor for adenovirus commonly used as a gene delivery vector. Down-regulation of CAR is often detected in several cancer types. Epigenetic modifiers such as histone deacetylase inhibitor FK228 (depsipeptide) have been shown to increase CAR expression as well as the uptake of adenovirus in bladder cancer in vivo and in vitro, indicating that altered transcriptional regulation of CAR is the key mechanism responsible for the decreased CAR levels in this cancer. In this study, we screened agents that could induce CAR expression in bladder cancer cells. Fifty-eight drugs with various chemical properties were tested. Ipriflavone and plant isoflavones were found to exhibit the ability to induce CAR gene expression in combination with FK228. Genistein, the natural isoflavone found in soybean, when combined with FK228, exerts a synergistic effect on CAR gene and protein expression in bladder cancer cells. Chromatin immunoprecipitation results showed an increased histone acetylation in the CAR promoter gene, which is due to the suppression of histone deacetylase activity by both agents. Also, our data indicated that combination treatment is a potent chemotherapeutic regimen for bladder cancer cells and the subsequent administration of recombinant adenovirus could further eliminate the remaining cells. Taken together, our results provide a strong rationale for combining chemotherapeutic and gene therapeutic agents to enhance the therapeutic efficacy in bladder cancer.

Adenoviridae↗
PubMed2000

Zinc finger and carboxyl regions of adenovirus E1A 13S CR3 are important for transactivation of the cytomegalovirus major immediate early promoter by adenovirus.

Reactivation of latent cytomegalovirus (CMV) is an important cause of disease in susceptible patients. We previously demonstrated that an adenovirus early gene product can transactivate the CMV major immediate early (IE) promoter in inflammatory cells. This effect was due to the conserved region 3 (CR3) of the adenovirus E1A 13S gene product. There are two domains in the CR3 region, a zinc finger (aa 147-177) and a carboxyl (aa 180-188) domain. Both are crucial for transactivation of downstream promoter elements of adenovirus in E1A 13S. We sought to determine if either or both of these specific domains is also necessary for transactivation of the CMV IE promoter by the adenovirus E1A 13S gene product. We cotransfected T-lymphocyte Jurkat cells and monocyte/macrophage-like THP-1 cells with plasmids expressing wild-type (WT) or CR3 mutant E1A 13S and a CMV IE chloramphenicol acetyltransferase (CAT) reporter construct. With extracts of cells coinfected with E1A WT set to 100%, mutation in the zinc finger domain, the carboxyl domain, or both domains decreased CMV IE CAT activity by >/= 96%. In contrast, a mutation in the region between the zinc finger and carboxyl domains reduced CMV IE CAT activity by only 24 to 26%. Mixing studies in Jurkat cells confirmed the importance of these domains. We also evaluated the active site of the CMV IE promoter involved in transactivation in THP-1 cells using CMV IE promoter deletions and single promoter element constructs. These studies showed that progressive deletion of the 19-bp CMV IE repeats containing cyclic AMP response element binding protein/activating transcription factor (CREB/ATF) sites resulted in progressive loss of activity. The importance of this element was confirmed using single promoter elements containing CMV IE 16-, 18-, 19-, and 21-bp repeats. Finally, using a 19-bp single promoter element construct and the CR3 mutants we demonstrated that mutations in the zinc finger (C171S) carboxyl region (S185N) or both regions (C171S/ S185N) resulted in significant (83, 94, and 85%) loss of activity. We conclude that the zinc finger and carboxyl domains of the CR3 region of E1A 13S are necessary for transactivation of the CMV promoter and that this occurs mainly through activation of the 19-bp CREB/ATF site of the promoter.

Adenoviridae↗
PubMed1989

Co-operative interactions between NFI and the adenovirus DNA binding protein at the adenovirus origin of replication.

The DNA-protein and protein-protein interactions proposed for the stability of nucleoprotein complexes at the origin of replication in prokaryotes are also thought to impart regulatory precision in eukaryotic DNA replication. This type of specificity can be observed, for example, during adenovirus DNA replication where efficient initiation requires that nuclear factor I (NFI) binds to the origin of DNA replication. Addition of purified NFI stimulates the initiation of adenovirus DNA replication in vitro in a reaction that is dependent on the concentration of the adenovirus DNA binding protein (DBP). However, the molecular basis for the synergistic action of NFI and DBP during replication is at present unknown. We report here that DBP increases the affinity of NFI for its binding site in the replication origin. DBP did not, however, increase the affinity of another eukaryotic sequence-specific DNA binding protein, EBP1, for its recognition site. Other single-stranded DNA binding proteins could not substitute for DBP in increasing NFI affinity for its binding site. In addition, DBP was found to alter the binding kinetics of NFI, both by increasing the rate of association and decreasing the rate of dissociation of NFI with the DNA template. The co-operativity between NFI and DBP was also demonstrated on another DNA template, a human NFI site (FIB2), suggesting that this interaction is of general occurrence and not restricted to the adenovirus origin of replication.

Adenoviridae↗
PubMed2000

Adenovirus-mediated in utero gene transfer in mice and guinea pigs: tissue distribution of recombinant adenovirus determined by quantitative TaqMan-polymerase chain reaction assay.

Fetal somatic cell gene therapy could become an attractive solution for some congenital genetic diseases or the disorders which manifest themselves during the fetal period. We performed adenovirus-mediated gene transfer to mice and guinea pig fetuses in utero and evaluated the efficiency of gene transfer by histochemical analysis and a quantitative TaqMan-polymerase chain reaction (TaqMan-PCR) assay. We first injected a replication-deficient recombinant adenovirus containing the Escherichia coli LacZ gene driven by a CAG promoter (AxCALacZ) into pregnant mice through the amniotic space, placenta, or intraperitoneal space of the fetus. Histochemical analysis showed limited transgene expression in fetal tissues. We then administered AxCALacZ to guinea pig fetuses in the late stage of pregnancy through the umbilical vein. The highest beta-galactosidase expression was observed in liver followed by moderate expression in heart, spleen, and adrenal gland. The transgene expression was also present in kidney, intestine, and placenta to a lesser degree. No positively stained cells were observed in lung, muscle, or pancreas except in the vascular endothelium of these organs. Quantitative measurement of recombinant adenoviral DNA by the TaqMan-PCR assay showed that the vast majority of the injected viruses was present in liver. The current study indicated that adenovirus-mediated gene transfer into guinea pig fetus through the umbilical vein is feasible and results in efficient transgene expression in fetal tissues. The experimental procedures using pregnant guinea pigs might serve as a good experimental model for in utero gene transfer. Since our TaqMan-PCR assay detects the LacZ gene, one of the most widely used reporter genes, it may be generally applicable to adenovirus quantification in various gene transfer experiments.

Adenoviridae↗
PubMed1999

A new goat adenovirus isolate proposed as the prototype strain for goat adenovirus serotype 1.

A virus isolated from the brain of a 3-year-old goat with encephalitis was identified as an adenovirus based on morphological and physicochemical characteristics. Neutralization tests and restriction endonuclease analysis comparing the caprine adenovirus with the prototype ovine and bovine adenovirus serotypes indicated that the caprine isolate was antigenically different and produced a unique restriction pattern and may represent a new adenovirus species. A limited seroepidemiologic study using adult goat and sheep sera collected from around the Unites States indicated that approximately 60 and 80 percent, respectively, had specific antibody for this isolate.

Adenoviridae↗
PubMedDate not supplied

Noninvasive of adenovirus tumor retargeting in living subjects by a soluble adenovirus receptor-epidermal growth factor (sCAR-EGF) fusion protein.

PURPOSE: To demonstrate that non-invasive bioluminescent imaging can monitor restricted expression from a nonreplicating adenovirus in which the cyclooxygenase-2 (COX-2) promoter drives firefly luciferase. PROCEDURES: Adenovirus in which the COX-2 promoter drives the firefly luciferase imaging gene was injected intratumorally into xenografts that express relatively low and relatively high levels of COX-2. Adenovirus that expresses Renilla Luciferase from the cytomegalovirus early promoter was co-injected, to normalize for injection, leakage, vascularization, etc. COX-2 restricted firefly luciferase and global Renilla Luciferase activities were measured by optical imaging techniques both in vivo and in isolated tissues. RESULTS: Dramatic reduction in hepatic luciferase expression after intravenous viral injection can be imaged non-invasively in living animals. Following intratumoral injection, luciferase levels in tumor xenografts that express differing endogenous COX-2 levels reflect the luciferase levels observed when these cells are infected in cell culture. Essentially no luciferase expression is observed in liver following intratumoral injection. CONCLUSION: Both tissue restricted expression and transcriptional redirection to tumors expressing COX-2 can be imaged non-invasively following injection of Adenovirus expressing firefly luciferase from the COX-2 promoter.

Adenoviridae↗
PubMed2003

Clinical trials of adenoviruses in brain tumors: a review of Ad-p53 and oncolytic adenoviruses.

Adenoviruses have been critical in the development of the molecular approaches to brain tumors. They have been engineered to function as vectors for delivering therapeutic genes in gene therapy strategies, and as direct cytotoxic agents in oncolytic viral therapies. This review outlines the uses of adenoviruses in brain tumor therapy by examining clinical trials of adenovirus-mediated p53 gene therapy and by reviewing the application of two conditionally replicative adenoviruses (CRAds) ONYX-015 and Delta 24 in brain tumors. The potential clinical use of CRAds that deliver trangenes, particularly p53, is also discussed.

Adenoviridae↗
PubMed2003

High throughput creation of recombinant adenovirus vectors by direct cloning, green-white selection and I-Sce I-mediated rescue of circular adenovirus plasmids in 293 cells.

Ability of replication-defective adenovirus vectors to achieve efficient gene transfer in most of the mammalian cell types makes them useful vehicles for many gene transfer applications, including their use in assessing gene function. High throughput creation of recombinant adenovirus becomes a critical path to the expanding utility of adenovirus vector technology. Here, we report a process in which recombinant adenovirus vectors are isolated as single molecular clones through a convenient direct cloning and green-white selection procedure, and directly transfected into 293 cells where virus is rescued through an enzymatic reaction mediated by an intron-encoding rare endonuclease I-Sce I. This process of enzymatic rescue of circular molecular clones was at least 10-fold more efficient than that using linearized clones for transfection. This method will facilitate a high throughput creation of vectors as required for screening gene function.

Adenoviridae↗
PubMed2005

Gutless adenovirus: last-generation adenovirus for gene therapy.

Last-generation adenovirus vectors, also called helper-dependent or gutless adenovirus, are very attractive for gene therapy because the associated in vivo immune response is highly reduced compared to first- and second-generation adenovirus vectors, while maintaining high transduction efficiency and tropism. Nowadays, gutless adenovirus is administered in different organs, such as the liver, muscle or the central nervous system achieving high-level and long-term transgene expression in rodents and primates. However, as devoid of all viral coding regions, gutless vectors require viral proteins supplied in trans by a helper virus. To remove contamination by a helper virus from the final preparation, different systems based on the excision of the helper-packaging signal have been generated. Among them, Cre-loxP system is mostly used, although contamination levels still are 0.1-1% too high to be used in clinical trials. Recently developed strategies to avoid/reduce helper contamination were reviewed.

Adenoviridae↗
PubMed1967

Immunofluorescent studies of the potentiation of an adenovirus-associated virus by adenovirus 7.

A quantitative immunofluorescent procedure for detection of viral antigen was used to study the potentiation of AAV-1 by Ad.7. AAV viral antigen formed only when the cells were also infected with adenovirus, and only in cell culture systems in which the adenovirus infection proceeded to completion. Ad. 7 infection of AGMK. cell cultures did not potentiate AAV unless the Ad. 7 infection was itself potentiated by SV40. Dose-response studies indicated that a single AAV particle and a single infectious Ad. 7 particle sufficed to initiate AAV antigen synthesis. Sequential inoculation studies showed that AAV antigen formed simultaneously with Ad. 7 viral antigen when the AAV was inoculated any time between 15 hr before to 10 hr after the Ad. 7, both antigens appearing about 15 hr after inoculation of Ad. 7. The AAV-1 antigen formation had a minimum latent period of 5 hr, as seen with Ad. 7 preinfection of 10 hr or more. When UV-irradiated Ad. 7 was used as helper, the AAV antigen still appeared simultaneously with the Ad. 7 viral antigen, even though the latter was delayed by 23 hr compared to nonirradiated virus. When the early replicative events of both viruses were allowed to proceed in FUDR-inhibited cells, and then the FUDR inhibition was reversed, AAV antigen formed within 2 hr, which was 3 hr before the Ad. 7 viral antigen appeared. It was inferred that the event in the adenovirus cycle that renders a cell competent to synthesize AAV occurs after the 10th hr and may be temporally associated with replication of the adenovirus DNA.

Adenoviridae↗
PubMed2005

Novel compound enables high-level adenovirus transduction in the absence of an adenovirus-specific receptor.

Viral vectors are extensively used to deliver foreign DNA to cells for applications ranging from basic research to potential clinical therapies. A limiting step in this process is virus uptake and internalization into the target cells, which is mediated by membrane receptors. Although it is possible to modify viral capsid proteins to target the viruses, such procedures are complex and often unsuccessful. Here we present a rapid, inexpensive system for improving transduction of cells, including those that lack receptors for adenovirus fiber proteins. Addition of GeneJammer (Stratagene, La Jolla, CA) during the adenovirus transduction led to a significant increase in both the total number of transduced cells and the level of transgene expression per cell. Studies using cell lines deficient in adenovirus receptors demonstrated that addition of GeneJammer provided a novel cellular entry mechanism for the virus. These findings were tested in a cell-based gene therapy system for the induction of bone, which is contingent on high-level expression of the transgene. Inclusion of GeneJammer in either Ad5BMP2 or Ad5F35BMP2 transduction of a variety of cells demonstrated a correlating increase in bone formation. The results suggest a novel and versatile method for achieving high-level transduction using adenovirus.

Adenoviridae↗
PubMed1974

Transformation potentials of the noninfectious (defective) component in pools of adenoviruses type 12 and simian adenovirus 7.

Pools of adenovirus 12 and simian adenovirus 7 were separated into four or five fractions by density gradient centrifugation in cesium chloride. Each fraction was analyzed for total in vitro infectivity units, total transformation activity, and for total virus particle (VP) content. Two major subpopulations were separated with mean densities of 1.30 +/- 0.02 and 1.34 +/- 0.02 g/ml, respectively. Virions in the 1.34 g/ml range were highly infectious (10(2) to 10(3) VP per infectivity unit) in contrast to virions at 1.30 g/ml density (10(4) to 10(5) VP per infectivity units). Transformation capacity was evenly distributed throughout fractions of both viruses, indicating that genetically incomplete or defective virus particles were not deficient in their ability to induce transformation. The average VP per transformation unit for adenovirus 12 (2.85 x 10(6)) and for simian adenovirus 7 (4.00 x 10(6)) did not vary significantly from fraction to fraction. These values were obtained with optimal input multiplicities of 16 to 64 VP per cell. At higher multiplicities the apparent increase in VP per transformation unit was attributable to the viral cytocidal effect on hamster cells. These studies revealed that quantitation of in vitro transformation based on VP multiplicities was more reliable than on the basis of infectious units. These estimates were independent of method of virus production, extraction, and purification.

Adenoviridae↗
PubMed2001

Enhancement of adenovirus vector entry into CD70-positive B-cell Lines by using a bispecific CD70-adenovirus fiber antibody.

Although many recombinant adenovirus vectors (rAd) have been developed, especially by using group C adenoviruses, to transfer and express genes, such rAd do not readily infect B-cell lines due to the lack of the coxsackievirus-adenovirus receptor. Bispecific antibodies have been used in different cell systems to facilitate entry of rAd into otherwise nonpermissive cells. Bispecific antibody is synthesized by covalently linking two monoclonal antibodies with distinct specificities. It has been shown that lymphoproliferative tumors commonly express the cell surface protein CD70, while this receptor is normally expressed on only a small subset of highly activated B cells and T cells. We therefore investigated whether a bispecific antibody with specificities for the adenovirus fiber protein and CD70 can facilitate rAd entry and subsequent expression of rAd-encoded genes in CD70-positive B cells. We found high CD70 expression on Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs), as well as some, but not all, Burkitt lymphoma (BL) lines. We show here that rAd encoding green fluorescent protein (Ad-GFP) infects EBV-transformed LCLs and a CD70-positive BL line 10- to 20-fold more efficiently in the presence of the CD70-fiber bispecific antibody. In contrast, the bispecific antibody does not enhance Ad-GFP infection in CD70-deficient BL cells. Using the CD70-fiber bispecific antibody, we increased the ability of rAd vectors encoding the EBV immediate-early proteins BZLF1 and BRLF1 to induce the lytic form of EBV infection in LCLs. These results indicate that the CD70-fiber bispecific antibody can enhance rAd infection of CD70-positive B cells and suggest the use of this vector to explore EBV-positive LCLs.

Adenoviridae↗
PubMed2001

Apical localization of the coxsackie-adenovirus receptor by glycosyl-phosphatidylinositol modification is sufficient for adenovirus-mediated gene transfer through the apical surface of human airway epithelia.

In well-differentiated human airway epithelia, the coxsackie B and adenovirus type 2 and 5 receptor (CAR) resides primarily on the basolateral membrane. This location may explain the observation that gene transfer is inefficient when adenovirus vectors are applied to the apical surface. To further test this hypothesis and to investigate requirements and barriers to apical gene transfer to differentiated human airway epithelia, we expressed CAR in which the transmembrane and cytoplasmic tail were replaced by a glycosyl-phosphatidylinositol (GPI) anchor (GPI-CAR). As controls, we expressed wild-type CAR and CAR lacking the cytoplasmic domain (Tailless-CAR). All three constructs enhanced gene transfer with similar efficiencies in fibroblasts. In airway epithelia, GPI-CAR localized specifically to the apical membrane, where it bound adenovirus and enhanced gene transfer to levels obtained when vector was applied to the basolateral membrane. Moreover, GPI-CAR facilitated gene transfer of the cystic fibrosis transmembrane conductance regulator to cystic fibrosis airway epithelia, correcting the Cl(-) transport defect. In contrast, when we expressed wild-type CAR it localized to the basolateral membrane and failed to increase apical gene transfer. Only a small amount of Tailless-CAR resided in the apical membrane, and the effects on apical virus binding and gene transfer were minimal. These data indicate that binding of adenovirus to an apical membrane receptor is sufficient to mediate effective gene transfer to human airway epithelia and that the cytoplasmic domain of CAR is not required for this process. The results suggest that targeting apical receptors in differentiated airway epithelia may be sufficient for gene transfer in the genetic disease cystic fibrosis.

3T3 Cells↗
PubMed2001

Promoter strength in adenovirus transducing vectors: down-regulation of the adenovirus E1A promoter in 293 cells facilitates vector construction.

Most adenovirus transducing vectors have the cytomegalovirus major immediate-early (CMV) or the Rous sarcoma virus long terminal repeat (RSV) promoter driving expression of the transgene. Both of these promoters are highly active in transfection and transduction assays in 293 cells, in which transducing vectors are constructed and grown, and in HeLa cells. The CMV promoter exhibits rapid activation while the RSV promoter exhibits a lag prior to the onset of viral DNA replication in transduction assays. While the use of very strong promoters facilitates expression of the transgene, high-level expression of certain gene products hinders virus construction and growth. For such genes, the use of the adenovirus type 5 E1A promoter offers advantages. The E1A promoter exhibits modest activity in HeLa cells after transfection or transduction, but very little activity in 293 cells, suggesting that the E1A promoter would permit construction and growth of vectors encoding deleterious gene products that could not be constructed with the CMV and RSV promoters. This idea was tested through attempts to construct viruses encoding the immunoglobulin loop 6 and transmembrane regions of the prostaglandin F2alpha receptor regulatory protein (FPRP), a product that inhibits adenovirus vector construction for reasons that are not clear. Only the E1A promoter permitted construction and growth of the transducing vector encoding the fragment of FPRP.

Adenovirus E1A Proteins↗