Promoter Attenuation in Gene Therapy: Interferon-γ and Tumor Necrosis Factor-α Inhibit Transgene Expression

Overview summary Transgene expression can be eliminated even in the presence of substantial amounts of vector DNA in the transduced cells, which suggests that mechanisms other than the antigen-specific immune response may mediate non-cytodestructive events that determine the presence of transgene expression. Our data indicate that the cytokines interferon-γ) (IFN-γ) and tumor necrosis factor-α (TNF-α) inhibit transgene expression from certain widely used viral promoters/enhancers (human cytomegalovirus immediate early, Rous sarcoma virus long terminal repeat, simian virus 40, Moloney murine leukemia virus long terminal repeat) delivered by adenoviral, retroviral, or plasmid vectors in vivo. Inhibition is at the mRNA level and cytokines do not cause vector DNA degradation, inhibit total cellular protein synthesis, or kill infected/transfected cells. Thus, cytokine-regulated promoter function rather than specific immune destruction could limit transgene expression. These results have significant implications for the construction of transfer vectors for human gene therapy because gene transfer vectors could be exposed to a cytokine-rich environment when they are administered in vivo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63157/1/hum.1997.8.17-2019.pd

Adenovirus-Mediated Gene Transfer of Viral Interleukin-10 Inhibits the Immune Response to Both Alloantigen and Adenoviral Antigen

Overview summary Adenoviral vectors are efficient for in vivo delivery of genes to a wide variety of tissue types, whereas the duration of expression is limited by the potent adenovirus-specific immune response directed to the infected cell. In this study, we demonstrate that adenovirus-mediated gene transfer and expression of viral interleukin-10 (vIL-10) not only prolongs murine cardiac allograft survival, but also inhibits the immune response toward adenoviral antigens, and thereby improves the persistence of the vector and extends transgene expression. These findings could be used to design a new generation of adenoviral vector that expresses both an immunosuppressive cytokine gene and another gene of interest. This strategy should have general application in many gene therapy settings other than transplantation. Nonetheless, although the efficacy of adenoviral vectors can be improved by incorporating immunosuppressive genes into the vector, there are also nonimmune mechanisms serving to limit vector gene expression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63260/1/hum.1997.8.11-1365.pd

Efficient Transfer of Genes into Murine Cardiac Grafts by Starburst Polyamidoamine Dendrimers

Overview summary Plasmid-mediated gene therapy has been used to deliver immunosuppressive molecules into allografts to prolong graft survival. However, direct injection of naked plasmid DNA is inefficient because transgene expression is low and transient. This study investigated the ability of Starburst dendrimers to augment plasmid-mediated gene transfer efficiency in a murine cardiac transplantation model. The results demonstrate that dendrimers increased the efficiency of transfer and expression of exogenous DNA in cardiac grafts. Improved expression of an immunosuppressive cytokine viral interleukin-10 (vIL-10) by dendrimers significantly prolonged allograft survival. The dose of DNA, the charge ratio of DNA to dendrimer, and the size generation of the dendrimers were all critical for prolongation of allograft survival. Thus, the use of the Starburst dendrimer as a carrier molecule for plasmid-mediated gene transfer improved the efficiency of transfer and expression, providing further therapeutic value for treatment of cardiac allograft rejection.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63156/1/hum.1998.9.4-553.pd

Spike 1 trimer, a nanoparticle vaccine against porcine epidemic diarrhea virus induces protective immunity challenge in piglets

Porcine epidemic diarrhea virus (PEDV) is considered the cause for porcine epidemic diarrhea (PED) outbreaks and hefty losses in pig farming. However, no effective commercial vaccines against PEDV mutant strains are available nowadays. Here, we constructed three native-like trimeric candidate nanovaccines, i.e., spike 1 trimer (S1-Trimer), collagenase equivalent domain trimer (COE-Trimer), and receptor-binding domain trimer (RBD-Trimer) for PEDV based on Trimer-Tag technology. And evaluated its physical properties and immune efficacy. The result showed that the candidate nanovaccines were safe for mice and pregnant sows, and no animal death or miscarriage occurred in our study. S1-Trimer showed stable physical properties, high cell uptake rate and receptor affinity. In the mouse, sow and piglet models, immunization of S1-Trimer induced high-level of humoral immunity containing PEDV-specific IgG and IgA. S1-Trimer-driven mucosal IgA responses and systemic IgG responses exhibited high titers of virus neutralizing antibodies (NAbs) in vitro. S1-Trimer induced Th1-biased cellular immune responses in mice. Moreover, the piglets from the S1-Trimer and inactivated vaccine groups displayed significantly fewer microscopic lesions in the intestinal tissue, with only one and two piglets showing mild diarrhea. The viral load in feces and intestines from the S1-Trimer and inactivated vaccine groups were significantly lower than those of the PBS group. For the first time, our data demonstrated the protective efficacy of Trimer-Tag-based nanovaccines used for PEDV. The S1-Trimer developed in this study was a competitive vaccine candidate, and Trimer-Tag may be an important platform for the rapid production of safe and effective subunit vaccines in the future

Evolutionary Analysis of Structural Protein Gene VP1 of Foot-and-Mouth Disease Virus Serotype Asia 1

Foot-and-mouth disease virus (FMDV) serotype Asia 1 was mostly endemic in Asia and then was responsible for economically important viral disease of cloven-hoofed animals, but the study on its selection and evolutionary process is comparatively rare. In this study, we characterized 377 isolates from Asia collected up until 2012, including four vaccine strains. Maximum likelihood analysis suggested that the strains circulating in Asia were classified into 8 different groups (groups I–VIII) or were unclassified (viruses collected before 2000). On the basis of divergence time analyses, we infer that the TMRCA of Asia 1 virus existed approximately 86.29 years ago. The result suggested that the virus had a high mutation rate (5.745 × 10−3 substitutions/site/year) in comparison to the other serotypes of FMDV VP1 gene. Furthermore, the structural protein VP1 was under lower selection pressure and the positive selection occurred at many sites, and four codons (positions 141, 146, 151, and 169) were located in known critical antigenic residues. The remaining sites were not located in known functional regions and were moderately conserved, and the reason for supporting all sites under positive selection remains to be elucidated because the power of these analyses was largely unknown

Подбор оборудования для эксплуатации нефтяной скважины

Результат исследования: Был подобран погружной электроцентробежный насос, для данной нефтяной скважины, достоинствами которого является простота конструкции, так же унифицированная база запасных частей и комплектующих изделий отечественного производства.Result of the research: A submersible electric centrifugal pump was selected, for this oil well, whose advantages are simplicity of designs, as well as a unified base of spare parts and components of domestic production

Foot and mouth disease vaccine efficacy in Africa: a systematic review and meta-analysis

BackgroundSeveral factors, such as diverse serotypes, vaccination methods, weak biosecurity, and animal movements, contribute to recurrent Foot-and-Mouth Disease Virus (FMDV) outbreaks in Africa, establishing endemicity. These outbreaks cost over $2 billion annually, prompting a high-priority focus on FMDV vaccination. Despite extensive efforts, vaccine efficacy varies. This study aims to evaluate routine foot and mouth disease (FMD) vaccines in Africa via systematic review and meta-analysis.MethodsA systematic review and meta-analysis were carried out following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Meta-analysis was conducted to assess the efficacy of FMDV vaccination using the meta for package of R.ResultsVaccinated animals have roughly a 69.3% lower chance of FMDV infection compared to unvaccinated animals, as indicated by the pooled results from the random-effects model, which showed a risk ratio (RR) of 0.3073. There was a statistically significant heterogeneity (p < 0.05) across all of the included articles.ConclusionOverall findings suggest that if properly planned and implemented, FMDV vaccination programs and strategies in Africa could help control the spread of the disease throughout the continent and beyond

Analysis of synonymous codon usage in Hepatitis A virus

<p>Abstract</p> <p>Background</p> <p>Hepatitis A virus is the causative agent of type A viral hepatitis, which causes occasional acute hepatitis. Nevertheless, little information about synonymous codon usage pattern of HAV genome in the process of its evolution is available. In this study, the key genetic determinants of codon usage in HAV were examined.</p> <p>Results</p> <p>The overall extent of codon usage bias in HAV is high in <it>Picornaviridae</it>. And the patterns of synonymous codon usage are quite different in HAV genomes from different location. The base composition is closely correlated with codon usage bias. Furthermore, the most important determinant that results in such a high codon bias in HAV is mutation pressure rather than natural selection.</p> <p>Conclusions</p> <p>HAV presents a higher codon usage bias than other members of <it>Picornaviridae</it>. Compositional constraint is a significant element that influences the variation of synonymous codon usage in HAV genome. Besides, mutation pressure is supposed to be the major factor shaping the hyperendemic codon usage pattern of HAV.</p