Linked Life Data

8934224

Source:http://linkedlifedata.com/resource/pubmed/id/8934224

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1997-3-3
pubmed:abstractText
Recombinant adeno-associated viruses (AAV) are among the most promising vectors for gene therapy of genetic diseases, including cystic fibrosis (CF). However, because of its small genome size, the capacity of AAV to package a therapeutic gene is limited. The efficiency of packaging the cystic fibrosis transmembrane conductance Regulator (CFTR) gene into AAV will be an important factor in determining whether recombinant AAV can be developed as a vector for transferring CFTR cDNA to the airway epithelia of patients with CF. Current understanding of the AAV biology suggests that AAV can package a genome slightly larger than the size of a wild-type genome. The precise range of the genome size and the efficiency of packaging have not been defined. Using a series of AAV vectors with progressively-increasing genome size, we were able to analyze quantitatively the packaging efficiency in relation to the vector size and to determine the size limit for packaging. The packaging efficiencies of AAV vectors of variable sizes were determined directly by assaying DNA contents of viral particles, and indirectly by analyzing their efficiency in transfer of a chloramphenicol acetyltransferase (CAT) reporter gene into target cells. Our studies showed that the optimal size of AAV vector is between 4.1 and 4.9 kb. Although AAV can package a vector larger than its genome size, up to 5.2 kb, the packaging efficiencies in this large size range were sharply reduced. When the AAV genome size was smaller than 4.1 kb, the packaging efficiency was also suboptimal. In contrast, when the size of the genome was less than half the length of the wild-type genome, two copies of the vector were packaged into each virion, suggesting that the copy number control during packaging is a "head-full" mechanism. Because the length of the minimal cDNA of CFTR is about 4.5 kb, these results suggest it is possible to package the CFTR gene into AAV if the combined length of transcriptional elements and ITRs is kept under 500 bp. The results of this study are important for directing the design of AAV vectors for efficient gene transfer, as well as for a better understanding of the mechanism of AAV genome packaging.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1043-0342
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2101-12
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Quantitative analysis of the packaging capacity of recombinant adeno-associated virus.
pubmed:affiliation
Department of Laboratory Medicine, University of California, San Francisco, 94143-0724, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't