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Biomedical subjects

P Gilles

Publications and source records attributed to P Gilles.

8 recordsLinked to original sources
PubMed2000

Inhibition of CCR5-dependent HIV-1 infection by hairpin ribozyme gene therapy against CC-chemokine receptor 5.

CCR-5 is a major cellular coreceptor for R5 strains of HIV-1. Individuals carrying a homozygous 32-base-pair deletion in this gene are apparently healthy and are relatively resistant to HIV-1 infection. Since CCR5 appears to be dispensable for the host, but important for initial HIV-1 infection, CCR5 mRNA is an excellent therapeutic target for inhibiting HIV-1 replication via ribozyme knockout. We report here that hairpin ribozymes are able to reduce cellular CCR5 mRNA and cell surface CCR5 when stably introduced into PM1 cells by transduction with recombinant adenoassociated viral vector. The ribozymes effectively protect the cells from infection by R5 HIV-1 strains or non-syncytium-inducing clinical isolates commensurate with a reduction in CCR5 mRNA. These results suggest a novel gene therapy approach to preventing or slowing the disease progression of HIV-1 infection.

CCR5 Receptor Antagonists↗
PubMed1993

Production of authentic human proapolipoprotein A-I in Escherichia coli: strategies for the removal of the amino-terminal methionine.

Several methods were compared with respect to the production of authentic, N-terminal methionine-free proapolipoprotein A-I in engineered Escherichia coli bacteria. A first approach consisted of treating the purified methionylated recombinant protein with an amino-peptidase, purified from Aeromonas proteolytica. A second series of strategies was based on the construction of proapo A-I encoding cassettes carrying built-in recognition sites suitable for specific in vitro cleavage of the products with kallikrein and enterokinase, respectively. Along the same line, a fusion between ubiquitin and proapo A-I was produced in E. coli with the prospect to achieve post-purification cleavage with yeast ubiquitin hydrolase. Finally, proapo A-I was fused to the signal peptide of the bacterial outer membrane protein, OmpA, aiming at an in situ conversion to authentic proapo A-I during secretion to the bacterial periplasm. The data showed that, out of these five systems, the OmpA signal peptide system and, to a lesser extent, the one involving the fusion to ubiquitin were the most efficient in yielding authentic proapo A-I from engineered Escherichia coli.

Amino Acid Sequence↗
PubMed1991

Plasmodium falciparum: recombinant baculoviruses direct the expression of circumsporozoite proteins in Spodoptera frugiperda cell cultures.

The DNA coding for the circumsporozoite protein (CPS) of Plasmodium falciparum has been cloned into the baculovirus expression vector pAcYM1 and expressed in Spodoptera frugiperda (Sf9) insect cells. Three DNA constructs have been made: the first one directs the synthesis of the complete CSP (aa 1-412), the second leads to the production of a species devoid of the anchor domain (aa 1-391) and the third one to a molecule lacking both signal and membrane anchor sequences (aa 18-391). All three recombinant CPS were produced at about 3 micrograms per 10(6) infected cells and were characterized in terms of immunoreactivity and apparent molecular weight. Analytical purification of the recombinant proteins was achieved by a combination of heat treatment, acidification, isoelectric focusing and ion exchange chromatography. The purified material, when injected into mice, generated only modest antibody responses, although antisera from immunized mice reacted with control CSP antigens carrying or not the major immunodominant repeat region.

Animals↗
PubMed1988

Dental health habits in Austria, England, Finland and Norway.

Individually, people can prevent dental caries by sugar restriction and periodontal disease by toothbrushing. The aim of this study was to determine the toothbrushing frequency and consumption of sweets and soft drinks in some European countries. The data were obtained during the winter of 1983-84 from schoolchildren aged 11.5, 13.5 and 15.5 in Austria, England, Finland and Norway. Except for England, the samples were nationally representative. The questionnaires were completed at school. Dental health habits apparently were best in Norway, as the toothbrushing frequency was highest and the consumption of sweets and soft drinks was lowest. The toothbrushing frequency of boys was lowest in Finland. The consumption of sweets and soft drinks was very high in Austria and England. Such international comparisons should be used when evaluating and directing national programmes of preventive dentistry.

Adolescent↗
PubMed1986

Amino acid requirements of Eikenella corrodens.

The amino acid requirements of asaccharolytic Eikenella corrodens strains were investigated and a minimal amino acid medium was developed. Single amino acid deletions performed in a chemically defined medium indicated that these strains required arginine, cysteine, histidine, lysine, and proline, and partially required tyrosine. These six amino acids plus aspartic acid, glutamic acid, and glycine supported growth of E. corrodens in a medium containing only inorganic salts and vitamins.

Amino Acids↗
PubMedDate not supplied

Production of human recombinant proapolipoprotein A-I in Escherichia coli: purification and biochemical characterization.

A human liver cDNA library was used to isolate a clone coding for apolipoprotein A-I (Apo A-I). The clone carries the sequence for the prepeptide (18 amino acids), the propeptide (6 amino acids), and the mature protein (243 amino acids). A coding cassette for the proapo A-I molecule was reconstructed by fusing synthetic sequences, chosen to optimize expression and specifying the amino-terminal methionine and amino acids -6 to +14, to a large fragment of the cDNA coding for amino acids 15-243. The module was expressed in pOTS-Nco, an Escherichia coli expression vector carrying the regulatable lambda PL promoter, leading to the production of proapolipoprotein A-I at up to 10% of total soluble proteins. The recombinant polypeptide was purified and characterized in terms of apparent molecular mass, isoelectric point, and by both chemical and enzymatic peptide mapping. In addition, it was assayed in vitro for the stimulation of the enzyme lecithin: cholesterol acyltransferase. The data show for the first time that proapo A-I can be produced efficiently in E. coli as a stable and undegraded protein having physical and functional properties indistinguishable from those of the natural product.

Amino Acid Sequence↗