The proteins encoded by early region 1 A (E1A) of human adenoviruses (Ad) modulate the expression of both adenovirus genes and various host cell genes. With these transcription‐regulating properties the E1A proteins redirect the cell's metabolism, which enables them to induce oncogenic transformation in rodent cells. The E1A proteins modulate transcription by interacting both with gene‐specific and general cellular transcription factors. Various members of the AP‐1 and ATF/CREB families of transcription factors are targets for E1A‐dependent regulation, including cJun, the (...) protein product of the c‐jun proto‐oncogene. The E1A proteins modulate cJun‐dependent transcription both positively and negatively, and affect the activity as well as the expression levels of cJun. By increasing the phosphorylation status of cJun, E1A can stimulate transcription regulated by cJun/ATF2 heterodimers. In contrast, E1A inhibits the expression of various metalloproteases by interfering with the DNA‐binding capacity of cJun/cJun and cJun/cFos dimers, which might involve the association of E1A with the putative transcriptional coactivator p300. Since the ability of E1A to alter cJun‐dependent transcription correlates with its transforming capacity, interference with cJundependent transcription may be an essential step in E1A‐induced transformation. (shrink)

For focal neurodegenerative diseases or brain tumors, localized delivery of protein or genetic vectors may be sufficient to alleviate symptoms, halt disease progression, or even cure the disease. One may circumvent the limitation imposed by the blood-brain barrier by transplantation of genetically altered cell grafts or focal inoculation of virus or protein. However, permanent gene replacement therapy for diseases affecting the entire brain will require global delivery of genetic vectors. The neurotoxicity of currently available viral vectors and the transient nature (...) of transgene expression invivomust be overcome before their use in human gene therapy becomes clinically applicable. (shrink)

The recent tragic and widely publicised death of Jesse Gelsinger in a gene therapy trial has many important lessons for those engaged in the ethical review of research. One of the most important lessons is that ethics committees can give too much weight to ensuring informed consent and not enough attention to minimising the harm associated with participation in research. The first responsibility of ethics committees should be to ensure that the expected harm associated with participation is reasonable. Jesse was (...) an 18-year-old man with a mild form of ornithine transcarbamylase (OTC) deficiency, a disorder of nitrogen metabolism. His form of the disease could be controlled by diet and drug treatment. On September 13 1999 a team of researchers lead by James Wilson at the University of Pennsylvania's Institute for Human Gene Therapy (IHGT) injected 3.8 X 1013 adenovirus vector particles containing a gene to correct the genetic defect. He was the eighteenth and final patient in the trial. The virus particles were injected directly into the liver. He received the largest number of virus particles in a gene therapy trial.1 Four days later he was dead from what was probably an immune reaction to the virus vector. This was the first death directly attributed to gene therapy. It resulted in worldwide publicity, an independent investigation, the Federal Drug Administration (FDA) suspending all trials at the IHGT, an FDA, and a senate subcommittee investigation. At a special public meeting at the National Institutes of Health (NIH) in December 1999, James Wilson, also the director of the IHGT, said they still did not understand fully what had gone wrong.2 Even though a massive dose had been used, only 1% of transferred genes reached the target cells. (None of the patients in the trial showed significant gene expression. Art …. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kennedy Institute of Ethics Journal 10.2 (2000) 171-174 [Access article in PDF] Bioethics Inside the Beltway The Oversight of Human Gene Transfer Research LeRoy Walters Jesse Gelsinger's death last September in a gene transfer study being conducted at the University of Pennsylvania has helped to spark a national debate. In part, this debate parallels the broader discussion of how human subjects research should be reviewed and regulated in the (...) United States. However, human gene transfer research is one of a handful of biomedical technologies that seem to deserve special attention, at least in the early years of their development.The major participants in the national debate on human gene transfer include the National Institutes of Health (NIH), the Food and Drug Administration (FDA), the National Bioethics Advisory Commission, members of Congress, biotechnology and pharmaceutical companies, disease-oriented advocacy groups, reporters, and academics. At the December 1999 meeting of the NIH Recombinant DNA Advisory Committee (RAC), the protocol that involved Jesse Gelsinger was a central focus of discussion, but other topics emerged as well. One ad hoc panel reviewed adverse events that had occurred in other research protocols using adenovirus vectors, while a second proposed changes in the general system for reporting adverse events to NIH and the RAC.During the first several months of the year 2000, the United States Congress also became involved in the human gene transfer debate. In February, Senator Bill Frist (R-TN) convened a hearing to which Jesse Gelsinger's father, representatives of NIH and FDA, and several other witnesses were invited. At approximately the same time, the House Commerce Committee and its Subcommittee on Oversight and Investigations initiated their own inquiries, asking the Office of Inspector General at the Department of Health and Human Services to review the oversight roles of NIH and FDA. In March and April, the House committee also wrote directly to the NIH Director, the FDA Commissioner, and the President of the University of Pennsylvania, requesting extensive documentation on gene transfer, in general, and the trial in which Jesse Gelsinger was involved, in particular. Congressman Henry Waxman (D-CA) and Senator Edward Kennedy (D-MA) have also raised questions and proposed solutions in multiple letters to the NIH Director and the Secretary of Health and Human Services. [End Page 171]The major general questions that have emerged from this discussion are the following:(1) What kinds of information about adverse events should be reported by researchers or sponsors during the course of human gene transfer trials?(2) To what group or groups should adverse-event information be reported? How often and in what ways should the information be analyzed?(3) Should the information about adverse events remain confidential, or should it be discussed publicly?(4) How can the disclosure and consent process in gene transfer trials be improved?(5) Which federal agency should have primary responsibility for overseeing human gene transfer research, and how can it best fulfill its oversight role?How these questions are answered will have immediate relevance to the field of human gene transfer research as it enters into its next phase. At the same time, the models that are created for this important cutting-edge field also may be useful in other complex or controversial arenas of biomedical research, for example, xenotransplantation or human embryonic stem-cell research. In addition, the lessons learned from this one important area of human subjects research may suggest ways to improve protections for all the volunteers who make clinical research--and medical progress--possible.In the remainder of this article, I will turn from reporting, in as objective a way as possible, on the status of the public policy debate about human gene transfer research to suggesting measures for improving the current oversight system for such research. My initial general recommendation is that we should not expect a single regulatory agency to be solely responsible for a field as large and dynamic as human gene transfer research. Rather, there should be some helpful redundancy or, to change the metaphor, checks and balances in the public oversight of this field. Thus, an... (shrink)

The expression of epithelial cell adhesion and cytoskeletal genes is orchestrated by an apparently unique set of rules. No tissue‐specific transactivator proteins have been found to drive them; only ubiquitous factors are utilized. In non‐epithelial cells, they are actively repressed. Moreover, it was recently found that a single protein (adenovirus E1a) coordinately represses non‐epithelial genes while inducing epithelial genes. A simple model is offered to explain how epithelial gene expression is coordinated. Under this model, the epithelial cell gene expression (...) program is a transcriptional ‘default’; that is, it occurs in the absence of tissue‐specific transactivation. Conversion to this default requires only that mesenchymal transactivators are not expressed, or that central ‘integrator’ proteins are inactive. In their absence, mesenchymal gene expression cannot occur. Moreover, because the repressors cease to be expressed, the epithelial genes are induced. Oncogenes generally cause the breakdown of the epithelial phenotype ‐ generating carcinomas ‐ so genes such as E1a that cause epithelial conversion may prove useful for both understanding and controlling cancer. (shrink)

Within the highly organized nuclear structure, specific nuclear domains (ND10) are defined by accumulations of proteins that can be interferon-upregulated, implicating ND10 as sites of a nuclear defense mechanism.Compatible with such a mechanism is the deposition of herpesvirus, adenovirus, and papovavirus genomes at the periphery of ND10. However, these DNA viruses begin their transcription at ND10 and consequently initiate replication at these sites, suggesting that viruses have evolved ways to circumvent this potential cellular defense and exploit it. Other ND10-associated (...) proteins belong to ubiquitin-related pathways. These findings, together with the accumulation of various overexpressed cellular and viral proteins, suggest that ND10 function as nuclear dumps or as nuclear depots. Consistent with the recruitment or deposition of various proteins and viral genomes adjacent to ND10, ND10 themselves may only be protein accumulations at specific but as yet undefined nuclear deposition sites. The concept of specific nuclear deposition sites may explain the juxtaposition of various nuclear bodies and allows testable predictions about a potential supramolecular regulatory mechanism whereby proteins are selectively segregated or released by global changes induced in nuclear functions such as viral infections, stress, or hormonal induction. BioEssays 20:660–667, 1998.© 1998 John Wiley & Sons Inc. (shrink)

Although 80–90% of adults are seropositive for antibodies against the human parvovirus adeno‐associated virus (AAV), infection has not been associated with either symptoms or disease. In cell culture, AAV infection is not productive unless there is a coinfection with a helper virus, either adenovirus or any type of herpes virus; in the absence of a helper virus coinfection the viral genome is integrated into the genome, usually at a specific site on chromosome 19q13.3‐qter. The integrated genome can be activated (...) and rescued by subsequent super infection by a helper virus. The high frequency of site‐specific integration by AAV and the lack of associated disease have encouraged the use of AAV as a vector for gene therapy. This review will focus on the molecular mechanisms involved in the establishment of, and rescue from, the latent state and their relevance to use of AAV as a vector. (shrink)

It may be possible, one day, to use gene therapy to treat diseases whose genetic defects have been discerned. Because many genes responsible for inherited eye disorders within the retina have been identified, diseases of the eye are prime candidates for this form of therapy. The eye also has the advantage of being highly accessible with altered immunological properties, important considerations for easy delivery of virus and avoidance of systemic immune responses. Currently, adenovirus, adeno‐associated virus and lentivirus have been (...) used to successfully transfer genetic material to retinal pigment epithelium and photoreceptor cells. By harnessing therapeutic genes to these viruses, researchers have been able to demonstrate rescue in rodent models of retinitis pigmentosa, providing evidence that this form of therapy can be effective in delaying photoreceptor cell death. Future challenges include confirming therapeutic effects in animal models with eyes more anatomically similar to those of humans and demonstrating long‐term rescue with minimal toxicity. BioEssays 23:662–668, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

The concept of human gene therapy came on the heels of fundamental discoveries on the nature and working of the gene. However, realistic prospects to correct the underlying cause of recessive genetic disorders through the transfer of wild‐type alleles of defective genes had to wait for the arrival of recombinant DNA technology. These techniques permitted the isolation and insertion of genes into the first recombinant delivery systems. The realization that viruses are natural gene carriers provided inspiration for gene therapy and, (...) as engineered vectors, viruses became prominent gene delivery vehicles. Nonetheless, when put in the context of human and non‐human primate studies, all vectors fell short of success regardless of their viral or non‐viral origin. Recognition of issues such as inefficient gene transfer and short‐lived or scant expression in the relevant cell type(s) prompted researchers to refine and develop several gene delivery systems, in particular those based on retroviruses, adeno‐associated viruses and adenoviruses. Concomitantly, available technology was deployed to tackle disorders that require few genetically corrected cells to attain therapy. BioEssays 27: 506–517, 2005. © 2005 Wiley periodicals, Inc. (shrink)

The retinoblastoma sensitivity protein (Rb) and the p53 gene product both appear to function as negative regulators of cell division or abnormal cellular growth in some differentiated cell types. Several types of cancers have been shown to be derived from cells that have extensively mutated both alleles of one or both of these genes, resulting in a loss‐of‐function mutation. In the case of the p53 gene, this mutational process appears to occur in two steps, with the first mutation at the (...) p53 locus resulting in a trans‐dominant phenotype. The mutant p53 gene product enters into an oligomeric protein complex with the wild‐type p53 protein derived from the other normal allele and such a complex is inactive or less efficient in its negative regulation of growth control. This intermediate stage of carcinogenesis selects for the proliferation of cells with one mutant allele, enhancing the probability of obtaining a cancer cell with both alleles damaged.The DNA tumor viruses have evolved mechanisms to interact with the Rb and p53 negative regulators of cellular growth in order to enhance their own replication in growing cells. SV40 and adenovirus type 5 produce viral encoded proteins that also form oligomeric protein complexes with p53 and Rb, presumably inactivating their functions. These viral proteins are also the oncogene products of these viruses. Thus, the mechanisms by which cancer may arise in a host, via mutations or virus infections, have fundamental common pathways effecting the same cellular genes and gene products; Rb and p53. (shrink)

Consistent with the complexity of the temporally regulated processes that must occur for growth and development of higher eukaryotes, it is now apparent that transcription is regulated by the formation of multi‐component complexes that assemble on the promoters of genes. These complexes can include (in addition to the five or more general transcription factors and RNA polymerase II) DNA‐binding proteins, transcriptional activators, coactivators, adaptors and various accessory proteins. The best studied example of a complex that includes a transcriptional adaptor, accessory (...) proteins and a DNA‐binding protein is that involving the herpes simplex virus VP16 protein. Evidence suggests that the adenovirus E1a protein and the cellular Sp1 and CTF/NF1 transcription factors also function through adaptors or coactivators. Each additional component of the transcription complex provides the cell with another point at which to exert control of gene expression. (shrink)

Numerous clinical, epidemiological and molecular findings link some types of Human Papillomaviruses (HPV) with cancer of the genital tract. They share a common pathway of transformation with a number of DNA tumour viruses, such as Adenovirus and SV40. Although all these viruses are termed ‘DNA tumour viruses’ and have similar in vitro transforming activities, Human Papillomavirus is the only one so far clearly involved in human cancer. Extensive studies on HPV E6 and E7 proteins have demonstrated their involvement in (...) malignant transformation. E6 and E7 bind the products of tumour suppressor genes, p53 and Rb1, respectively, modifying or inactivating their normal functions. The Rb1 and p53 genes are deleted or mutated in several cancers and both proteins regulate the transcription of genes involved in cell cycle progression control. The E6/p53 and E7/Rb1 interactions result in a deregulation of the cell cycle with loss of control of crucial cellular events, such as DNA replication, DNA repair and apoptosis. (shrink)

Severe COVID‐19 is often accompanied by coagulopathies such as thrombocytopenia and abnormal clotting. Rarely, such complications follow SARS‐CoV‐2 vaccination. The cause of these coagulopathies is unknown. It is hypothesized that coagulopathies accompanying SARS‐CoV‐2 infections and vaccinations result from bacterial co‐infections that synergize with virus‐induced autoimmunity due to antigenic mimicry of blood proteins by both bacterial and viral antigens. Coagulopathies occur mainly in severe COVID‐19 characterized by bacterial co‐infections with Streptococci, Staphylococci, Klebsiella, Escherichia coli, and Acinetobacter baumannii. These bacteria express unusually (...) large numbers of antigens mimicking human blood antigens, as do both SARS‐CoV‐2 and adenoviruses. Bacteria mimic cardiolipin, prothrombin, albumin, and platelet factor 4 (PF4). SARS‐CoV‐2 mimics complement factors, Rh antigens, platelet phosphodiesterases, Factors IX and X, von Willebrand Factor (VWF), and VWF protease ADAMTS13. Adenoviruses mimic prothrombin and platelet factor 4. Bacterial prophylaxis, avoidance of vaccinating bacterially infected individuals, and antigen deletion for vaccines may reduce coagulopathy risk. Also see the video abstract here: https://youtu.be/zWDOsghrPg8. (shrink)