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Biomedical subjects

G Gribaudo

Publications and source records attributed to G Gribaudo.

62 records · Page 4Linked to original sources
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Transcriptional regulation of eukaryotic gene expression by cis-acting DNA sequences.

Initiation of transcription represents an early and critical event in eukaryotic gene expression. Control of the rate of initiation is one means by which the cellular differentiation and development can be regulated. This brief review will focus on some characteristics of cis-acting DNA signal structures that are located upstream from the initiation site for RNA transcription and required for modulation of gene expression in higher organisms.

Animals↗
PubMedDate not supplied

Production of polyclonal antibodies against the 40 kDa form of human 2'-5' oligoadenylate synthetase.

A 17-aminoacid peptide corresponding to the C terminal of the smaller form of human 2'-5' oligoadenylate synthetase was coupled to keyole lymphet haemocyanin (KLH) and used as immunogen in rabbits. After a cycle of four immunizations two animals produced immunoglobulins able to recognize the 17-aminoacid peptide as evaluated in ELISA assays. The specific Ig were purified by an immunoadsorbent with the peptide immobilized on Sepharose CL-4B and used in Western blot employing either protein A iodinated or conjugated with peroxidase as indicator system. The results obtained using extracts from HeLa or WISH cells treated for 15 hr with HuIFN-alfa as antigen demonstrate that the anti-peptide antibodies recognize the 40 kDa form of the 2'-5' oligoadenylate synthetase enzyme complex. These antibodies therefore represent a useful tool for monitoring the induction of the above enzyme.

2',5'-Oligoadenylate Synthetase↗
PubMedDate not supplied

[Cefonicid toxicity. I. Effects on the reactivity of the specific immune system].

The degree of toxicity of the antibiotic Cefonicid on the cellular reactivity of the immune system was evaluated. The effects on some lymphokine (IL-2 and IFN-gamma) production and the degree of proliferation of splenic lymphocytes following mitogen stimulation have been considered. Our results show that Cefonicid does not impair the immune response, except at very high doses (500 micrograms/ml).

Animals↗
PubMedDate not supplied

[Gamma-interferon: physico-chemical and biological characteristics].

In the present study we discuss some aspects of the Interferon System, with particular regard to the immune interferon (IFN-gamma) that, besides its antiviral activity, displays the capability to modulate the immune response against a variety of antigens such as viruses, bacteria, protozoa and tumor cells.

Animals↗
PubMedDate not supplied

[Protein p53 inhibits the activity of the enhancer of the immediate-early genes of murine cytomegalovirus].

The protein encoded by the tumor suppressor gene p53 can complex and functionally interact with cytomegalovirus proteins produced during the immediate-early phase of infection. The functions of these complex are unclear but there is some evidence to suggest that binding of p53 to these viral proteins may inactivate p53 functions. Recent reports have shown that p53 is involved in regulation of transcription. In this study we have considered the possibility that p53 may regulate transcription of cytomegalovirus immediate early genes which play a crucial role for virus replication. Here we report that experiments in which NIH 3T3 cells were cotransfected with a p53 expression plasmid together with a reporter gene linked to the mouse cytomegalovirus immediate-early enhancer/promoter revealed that wild type p53 could efficiently reduce the transcriptional activity of this viral regulatory sequence. By contrast expression of a mutated p53 correlated with a much smaller reduction of transcription. Deletion mutants analysis of the enhancer revealed that repression of transcription by p53 requires a minimal promoter containing an SP1 consensus sequence and a TATA box.

3T3 Cells↗
PubMedDate not supplied

[Serum stimulates the transcriptional activity of the enhancer of the immediate-early genes of the murine cytomegalovirus through p21 ras].

The analysis of the MCMV IE enhancer revealed the presence of many putative binding sites for the transcription factors AP-1 and NFkB. Previous studies suggested that such factors represent a final target for the metabolic cascade triggered by serum and growth factors. On these basis we wanted to verify if serum stimulates the transcriptional activity of the MCMV IE enhancer through p21ras and AP-1 and NFkB according to the actual model of transduction of the mitogenic signal. Our data demonstrate that serum stimulates the MCMV IE enhancer through a pathway in which the p21ras is involded, as demonstrated by using the dominant inhibitory mutant ras(Asn 17). Moreover deletion mutant analysis of the enhancer showed that the serum responsive region lies between nucleotides -1280 and -285 and contains a high concentration of putative AP-1 and NFkB binding sites.

3T3 Cells↗