Control elements of the tetracycline-resistance operon encoded in Tn10 of Escherichia coli have been utilized to establish a highly efficient regulatory system in mammalian cells. By fusing the tet repressor with the activating domain of virion protein 16 of herpes simplex virus, a tetracycline-controlled transactivator (tTA) was generated that is constitutively expressed in HeLa cells. This transactivator stimulates transcription from a minimal promoter sequence derived from the human cytomegalovirus promoter IE combined with tet operator sequences. Upon integration of a luciferase gene controlled by a tTA-dependent promoter into a tTA-producing HeLa cell line, high levels of luciferase expression were monitored. These activities are sensitive to tetracycline. Depending on the concentration of the antibiotic in the culture medium (0-1 microgram/ml), the luciferase activity can be regulated over up to five orders of magnitude. Thus, the system not only allows differential control of the activity of an individual gene in mammalian cells but also is suitable for creation of "on/off" situations for such genes in a reversible way.

https://www.pnas.org/content/pnas/89/12/5547.full.pdf

Tight control of gene expression in mammalian cells by tetracycline-responsive promoters.

RNA and DNA expression vectors containing genes for chloramphenicol acetyltransferase, luciferase, and beta-galactosidase were separately injected into mouse skeletal muscle in vivo. Protein expression was readily detected in all cases, and no special delivery system was required for these effects. The extent of expression from both the RNA and DNA constructs was comparable to that obtained from fibroblasts transfected in vitro under optimal conditions. In situ cytochemical staining for beta-galactosidase activity was localized to muscle cells following injection of the beta-galactosidase DNA vector. After injection of the DNA luciferase expression vector, luciferase activity was present in the muscle for at least 2 months.

https://science.sciencemag.org/content/sci/247/4949/1465.full.pdf

Direct gene transfer into mouse muscle in vivo.

The nucleotide sequence of the luciferase gene from the firefly Photinus pyralis was determined from the analysis of cDNA and genomic clones. The gene contains six introns, all less than 60 bases in length. The 5' end of the luciferase mRNA was determined by both S1 nuclease analysis and primer extension. Although the luciferase cDNA clone lacked the six N-terminal codons of the open reading frame, we were able to reconstruct the equivalent of a full-length cDNA using the genomic clone as a source of the missing 5' sequence. The full-length, intronless luciferase gene was inserted into mammalian expression vectors and introduced into monkey (CV-1) cells in which enzymatically active firefly luciferase was transiently expressed. In addition, cell lines stably expressing firefly luciferase were isolated. Deleting a portion of the 5'-untranslated region of the luciferase gene removed an upstream initiation (AUG) codon and resulted in a twofold increase in the level of luciferase expression. The ability of the full-length luciferase gene to activate cryptic or enhancerless promoters was also greatly reduced or eliminated by this 5' deletion. Assaying the expression of luciferase provides a rapid and inexpensive method for monitoring promoter activity. Depending on the instrumentation employed to detect luciferase activity, we estimate this assay to be from 30- to 1,000-fold more sensitive than assaying chloramphenicol acetyltransferase expression.

Firefly luciferase gene: structure and expression in mammalian cells.

Cytotoxic T lymphocytes (CTLs) specific for conserved viral antigens can respond to different strains of virus, in contrast to antibodies, which are generally strain-specific. The generation of such CTLs in vivo usually requires endogenous expression of the antigen, as occurs in the case of virus infection. To generate a viral antigen for presentation to the immune system without the limitations of direct peptide delivery or viral vectors, plasmid DNA encoding influenza A nucleoprotein was injected into the quadriceps of BALB/c mice. This resulted in the generation of nucleoprotein-specific CTLs and protection from a subsequent challenge with a heterologous strain of influenza A virus, as measured by decreased viral lung titers, inhibition of mass loss, and increased survival.

https://science.sciencemag.org/content/sci/259/5102/1745.full.pdf

Heterologous protection against influenza by injection of DNA encoding a viral protein

https://www.cell.com/cell/pdf/0092-8674(92)90479-V.pdf

9-cis retinoic acid is a high affinity ligand for the retinoid X receptor

A cDNA library was constructed from firefly (Photinus pyralis) lantern poly(A)+ RNA, using the Escherichia coli expression vector lambda gt11. The library was screened with anti-P. pyralis luciferase (Photinus luciferin:oxygen 4-oxidoreductase, EC 1.13.12.7) antibody, and several cDNA clones expressing luciferase antigens were isolated. One clone, lambda Luc1, contained 1.5 kilobase pairs of cDNA that hybridized to a 1.9- to 2.0-kilobase band on a nitrocellulose blot of electrophoretically fractionated lantern RNA. Hybridization of the cloned cDNA to lantern poly(A)+ RNA selected an RNA that directed the in vitro synthesis of a single polypeptide. This polypeptide comigrated with luciferase on NaDodSO4/PAGE and produced bioluminescence upon the addition of luciferin and ATP. A 1.8-kilobase-pair cDNA was isolated by probing the firefly cDNA library with the cDNA from lambda Luc1. This cDNA contained sufficient coding information to direct the synthesis of active firefly luciferase in E. coli.

https://www.pnas.org/content/pnas/82/23/7870.full.pdf

Cloning of firefly luciferase cDNA and the expression of active luciferase in Escherichia coli.

Synthesis of Active Firefly Luciferase by in Vitro Translation of RNA Obtained From Adult Lanterns

A lambda gt11 human hepatoma cDNA expression library was screened with antibodies to human alpha-L-fucosidase, a lysosomal enzyme whose activity is deficient in the human autosomal recessive disease fucosidosis. Three positive clones were identified after screening 9 X 10(6) plaques. One of these was sequenced and found to be spurious, probably representing an out-of-frame cDNA that gave rise to amino acid sequences of unknown length that crossreacted with alpha-L-fucosidase. A second clone, lambda AF3, was isolated which, after establishment in Escherichia coli BNN103, gave rise to a fusion protein of Mr 154,000 containing a human fragment of Mr 40,000 that represented 80% of the mature processed enzyme (Mr 50,000). Southern blot analysis of mouse and human chromosomal DNA confirmed the human origin of insert AF3. The nucleotide sequence of AF3 was determined and colinearity was established between 270 nucleotides and 90 amino acids in alpha-L-fucosidase. AF3 was found to contain 1058 base pairs and to code for 347 amino acids of alpha-L-fucosidase. Four potential glycosylation sites were identified. The frequency of lambda AF3 in the hepatoma library was 0.0018%.

https://www.pnas.org/content/pnas/82/4/1262.full.pdf

Molecular cloning of a cDNA for human alpha-L-fucosidase.

A human hepatoma cDNA library was constructed in λgt11, a bacteriophage vector that was designed to express cDN A-encoded antigenic determinants in Escherichia coli. The cDNA expression li...

J R de Wet

Papers

Firefly luciferase gene: structure and expression in mammalian cells.

Cloning of firefly luciferase cDNA and the expression of active luciferase in Escherichia coli.

Synthesis of Active Firefly Luciferase by in Vitro Translation of RNA Obtained From Adult Lanterns

Molecular cloning of a cDNA for human alpha-L-fucosidase.

Chromogenic Immuno detection of Human Serum Albumin and α-l-Fucosidase Clones in a Human Hepatoma cDNA Expression Library