Researchers compile West Nile gene "dictionary"

By Julie Steenhuysen

CHICAGO (Reuters) - Researchers have traced all of the proteins and enzymes used by the West Nile virus to infect cells, and found 305 genes that could serve as targets for treatments.

"It comprises a dictionary of all of these genes that are critical for West Nile virus infection of a cell," said Dr. Erol Fikrig of Yale University in New Haven, Connecticut, whose study was published on Wednesday in the journal Nature.

West Nile virus infected an estimated 175,000 people in the United States last year, killing 117 and causing serious disease in 1,227 people, the U.S. Centers for Disease Control and Prevention reported last month.

There is no specific treatment for the infection caused by the mosquito-borne virus.

Fikrig's team deployed a new technology using small interfering RNAs or siRNAs to scan the human genome looking for all the genes that could be hijacked by this virus.

While DNA carries the body's genetic instruction book, RNA is the genetic material that gives cells their marching orders. Small interfering RNAs are bits of genetic material that can shut down individual genes.

Using this technology, Fikrig's team was able to systematically remove 21,121 human genes to find which ones the virus uses.

"We knocked them out individually and then we infected those cells with the West Nile virus to see if the infection was reduced or increased," Fikrig said in a telephone interview.  Continued...