The outcome of tuberculosis infection in mice depends in part on how quickly bacteria-fighting T cells can get to the lungs. According to a new study that will appear online on June 14th in the Journal of Experimental Medicine (www.jem.org), another group of T cells delays their arrival.
Previous research has shown that ridding the body of the hindering T cells--known as regulatory T cells--enhances the body's ability to fight off TB-causing bacteria. But exactly when and where regulatory T cells act was uncertain. The new study shows that these cells are activated at the same time and place as their bacteria-fighting "effector" cell counterparts. In response to infection, both populations expand in the lymph nodes that drain the lung. As a result, fewer effector T cells become activated and are dispatched to the lungs to fight the bug.
Others have shown that the most deadly strains of TB generate the most regulatory T cells, suggesting that this may be a tactic used by the bacteria to sidestep immune attack. Whether clinicians can devise a strategy to interfere with these troublesome cells in humans remains to be seen.
About The Journal of Experimental Medicine
The Journal of Experimental Medicine (JEM) is published by The Rockefeller University Press. All editorial decisions on manuscripts submitted are made by active scientists in conjunction with our in-house scientific editors. JEM content is posted to PubMed Central, where it is available to the public for free six months after publication. Authors retain copyright of their published works and third parties may reuse the content for non-commercial purposes under a creative commons license. For more information, please visit www.jem.org.
Shafiani, S., et al. 2010. J. Exp. Med. doi:10.1084/jem.20091885.