Gene Found to Activate Tuberculosis

U.S. researchers have found the genetic changes that the tuberculosis bacterium undergoes in its live host — a clue that could lead to new treatments.

U.S. researchers have found the genetic changes that the tuberculosis bacterium undergoes in its live host — a clue that could lead to new treatments. The experiment, by researchers at the University of Texas Southwestern Medical School, is the first to use gene-chip technology for genomic analysis of gene expression during the course of infection in a living host. Gene chips are postage stamp-sized devices containing many tiny cells, each of which holds DNA from a different gene, allowing a large number of genetic tests to be carried out at once. The researchers analyzed the bacterium’s gene activity in healthy mice, as well as in mice with poor immune systems and in lab cultures. They activated a specific set of tuberculosis genes 21 days after infection — a critical time in the progression of the disease. The findings indicate the genes are activated to help the pathogen survive within the host. “We found some genes are turned down to stay beneath the immune system’s radar,” said Dr. Stephen Albert Johnston, director of the school’s Center for Biomedical Inventions. The findings could help develop future drugs and vaccines and prevent the pathogen’s use as a biological weapon, Johnston said.(Source: United Press International, March 2004)