Biomedical subjects

C Auriche

Publications and source records attributed to C Auriche.

3 recordsLinked to original sources

PubMed2004

Gene therapy progress and prospects: episomally maintained self-replicating systems.

The use of nonviral gene therapy vectors has been hampered by low level of transfection efficiency and lack of sustained gene expression. Episomal self-replicating systems may overcome these hurdles through their large packaging capacity, stability and reduced toxicity. This article reviews three classes of episomal molecules that have been tested with possible therapeutic genes: (1) self-replicating circular vectors, containing the Epstein-Barr virus (EBV) elements oriP and EBNA1; (2) small circular vectors containing scaffold/matrix attachment regions (S/MARs) as cis-acting elements to maintain the episomal status of the vector; (3) chromosomal vectors, based on the functional elements of the natural chromosomes. The studies reported validate the use of episomal vectors to obtain stable and prolonged gene expression, although reveal some limitations that necessitate additional work.

Chromosomes, Artificial↗

PubMed2001

Molecular and cytological analysis of a 5.5 Mb minichromosome.

Mammalian artificial chromosomes (MACs) provide a new tool for the improvement of our knowledge of chromosome structure and function. Moreover, they constitute an alternative and potentially powerful tool for gene delivery both in cultured cells and for the production of transgenic animals. In the present work we describe the molecular structure of MC1, a human minichromosome derived from chromosome 1. By means of restriction and hybridization analysis, satellite-PCR, in situ hybridization on highly extended chromatin fibres, and indirect immunofluorescence, we have established that: (i) MC1 has a size of 5.5 Mb; (ii) it consists of 1.1 Mb alphoid, 3.5 Mb Sat2 DNA, and telomeric and subtelomeric sequences at both ends; (iii) it contains an unusual region of interspersed Sat2 and alphoid DNAs at the junction of the alphoid and the Sat2 blocks; and (iv) the two alphoid blocks and the Sat2-alphoid region bind centromeric proteins suggesting that they participate in the formation of a functional kinetochore.

Animals↗

PubMed1999

Use of a human minichromosome as a cloning and expression vector for mammalian cells.

A natural human minichromosome (MC1) derived from human chromosome 1 was shown to be linear and to have a size of 5.5 Mb. Human IL-2 cDNA and the neo gene were co-transfected into a MC1-containing human-CHO hybrid cell line. Integration of the foreign genes was directed to the pericentromeric region of MC1 by co-transfection of chromosome 1-specific satellite 2 DNA. A number of G418-resistant transfectants were obtained and expression of IL-2 was determined. FISH analysis demonstrated co-localization in the minichromosome of the IL-2 gene and of the satellite 2 DNA. An IL-2-producing clone was used in cell fusion experiments with IL-2-dependent murine CTLL cells to generate CTLL-human hybrids containing the modified minichromosome (MC1- IL2 ). The hybrids were able to grow in medium lacking IL-2 for 17 mean population doublings (MPD), indicating that expression of the cytokine was sufficient to relieve the IL-2 dependence of CTLL proliferation. Endogenous IL-2 production delayed the onset of apoptosis in the IL-2-dependent CTLL cells. Mitotic stability was shown to be 100% in the human-CHO hybrids and 97% per MPD in CTLL cells. These results demonstrate that a natural human minichromosome can be utilized as a cloning and expression vector for mammalian cells and that the MC1 minichromosome can be engineered to deliver IL-2 to two types of cells, fibroblasts and lymphocytes.

Animals↗