The researchers have combined several gene manipulation techniques and incorporated them into a single lentiviral vector ?a gene delivery system partly derived from HIV. When injected into living cells ?either in vitro or in vivo ?the genetic material aboard the lentiviral vector joins the genetic material in the nucleus of the cell, causing the cell to express the protein encoded by the new gene. This versatile package can also carry bits of RNA that stop the cell from expressing one of its own genes, by way of RNA interference. But the cargo that makes this tool really novel and exciting is a fusion protein that acts as a kind of remote control. By administering an antibiotic, the genetic manipulation ?either the transgenic material introduced by the lentivirus, or the gene silencing via RNA interference--can be switched on or off at will.
An all-in-one tool like this ?efficiently combining techniques that each previously required separate delivery ?will likely see wide use in genetic research and in clinical gene therapy applications. It is particularly applicable for use in stem cells, embryonic cells and tissues and organs that are amenable to genetic transduction.
"It's a flexible way to regulate the expression of genes in a cell," says EPFL professor Didier Trono. "The lentiviral vector integrates in an irreversible fashion into the cell and is then part of its genetic cargo and part of the genetic cargo of all its progeny."
The efficiency of the lentiviral vector will make it easier to create transgenic animals used in studying human genetic diseases such as Parkinson's, Alzheimer's or Huntington's diseases. The expression of the gene can be turned on and off
Source:Ecole Polytechnique F茅d茅rale de Lausanne