The expression of transfected genes in mammalian cells is rapidly repressed by epigenetic mechanisms such that, within a matter of weeks, only a fraction of the cells in most clonal populations still exhibit detectable expression. This problem can become prohibitive when one wants to express two ectopically introduced genes, as is necessary to establish cell lines that harbor genes regulated by...

The applicability of tightly regulated transgenesis in domesticated animals is severely hampered by the present lack of knowledge of regulatory mechanisms and the long generation intervals. To capitalize on the tightly controlled expression of mammalian genes made possible by using prokaryotic control elements, we have used a single-step transduction to introduce an autoregulative tetracycline-...

results a significant increase in blood abca1 (ex group p < 0.002, t = - 9.876) and apo a-i (ex group p < 0.05, t = 2.76) gene expression was shown following the 12 weeks of training. plasma high-density lipoprotein-cholesterol (hdl-c) concentration increased (p < 0.001, t = 4.90 respectively) while plasma low-density lipoprotein-cholesterol (ldl-c) concentration decreased (p < 0.001, t = 4.27)...

We closely mimicked the in vivo setting in which sporadic hepatocarcinoma occurs by establishing a transgenic mouse model carrying regulatable SV40 early sequences under the control of the regulatory sequences of the human antithrombin III gene that confer hepatic expression. In this system, floxed dormant oncogenic sequences became functional after excision due to adenoviral expression of Cre ...

While naked DNA gene transfer in vivo usually results in transient gene expression, in some cases long-term transgene expression can be achieved. Here we demonstrate that cis-acting DNA elements flanking the transgene expression cassette and components in the plasmid backbone can significantly influence expression levels from nonviral vectors. To demonstrate this, we administered our most robus...

We report here an alternative and easy approach to generate sufficient quantity of minimal gene expression cassette (promoter–open reading frame–terminator) DNA by PCR amplification using high fidelity DNA polymerases. Isolating the minimal gene cassette DNA in large quantities by restriction digestion and gel extraction for biolistic-mediated ‘clean DNA’ transformation, is not only a cumbersom...

BACKGROUND The most widespread, efficient prokaryotic protein-producing system is one where the T7 phage polymerase recognizes the T7 phage promoter (T7 p/p system). Unfortunately, in this system, target protein expression gradually declines and is often undetectable following 3 to 5 subcultures. Although a number of studies have attempted to stabilize the expression levels of the T7 p/p system...

Abstract Exhausted immune responses to chronic diseases represent a major challenge global health. To explore their cell fate and plasticity in exhaustion, we analyzed CD4+T cells mouse model with regulatable antigen presentation. When the are driven through effector phase, then exposed different levels of persistent antigen, they lose Th1 functions, upregulate exhaustion markers, resemble natu...