Human cells, with their two sets of chromosomes, do not lend themselves to large-scale genetic screens as simple model organisms such as yeast have so profitably done.
Thijn Brummelkamp at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, and his colleagues have devised a way around the problem. Using a cell line with only one copy of most human chromosomes, they inactivated various genes using a method called insertional mutagenesis. The researchers then screened cells that were resistant to particular pathogens to see which genes invaders might rely on to attack.
Using the technique, the team identified two host genes used by the influenza H1N1 virus to infect cells, as well as genes exploited by other bacterial toxins to kill host cells. The authors say the method could help in developing new antiviral therapies.