Researchers have identified a group of genes that help defend the bacterium that causes tuberculosis (TB) from its host's immune system. Blocking the effects of these genes may offer new possibilities for treating the disease, which infects about two billion individuals worldwide.

K. Heran Darwin from Cornell University, New York, and colleagues analysed the genes of mutant Mycobacterium tuberculosis that were abnormally susceptible to the nitric oxide and other nitrogen compounds that human cells releases to help control the infection.

In this week’s Science, they report that they have identified the genes that are necessary for resistance against the nitrogen compounds. The results suggest that a protein complex called the ‘proteasome’, which helps degrade other proteins, is key to the mycobacteria's defence.

Link to paper by K. Heran Darwin et al in Science

Link to perspectives article in Science: Chemical warfare and mycobacterial defence

Reference: Science 302, 1963 (2003) / Science 302, 5652 (2003)