New Development in the reign of tuberculosis

A study led by Omar H. Vandal,a post-doctoral research fellow at Weill Cornell Medical College has recently reported about a mycobacterial membrane protein called Rv3671c which functions to protect the mycobacterium from acidifying host's acidic attack strategy of macrophages. They have their study published in Nature Medicine. However, they have reported of carrying out further studies on this topic.

Mode of mycobacterial attack

Mycobacterium tuberculosis when attacks the host, the alveolar macrophages engulfs the mycobacteria by phagocytosis. The mycobacteria, however escapes the macrophage attack by few ways like preventing apoptosis of macrophage, surviving the acidic pH of phagosome etc. Having escaped the attack, it multiplies inside the macrophage and finally reinfects new alveolar macrophages.It also escapes the attack by preventing the release of interferon-gamma which further saves the mycobacterium from death. Moreover, it prevents the release of STAT-6 (Signal transducer and activator of transcription-6) giving additional advantage to the mycobacterium.

Mycobacterium tuberculosis (taken from http://en.wikipedia.org/wiki/Image:TB_Culture.jpg) 

Current Research

Omar H. Vandal identified that Rv3671c helps the mycobacterial to resist the acidic pH of the phagosome of alveolar macrophage. Even the scientists grew the mycobacterium in-vitro in acidic pH and found out that those lacking the membrane protein could not withstand the intense acidity of phago-lysosome and hence got killed.

Therapeutic Potential

This property of mycobacterium is suggestive of development of a new class of drugs that can target Rv3671c, thereby killing away the mycobacterium right inside the macrophage and preventing its spread and also relapse. This would indeed open up a new way of doing away with multi-drug resistance of Mycobacterium tuberculosis (M.Tb) and also minimize the global health threat due to tuberculosis.

Reference Links

http://www.nature.com/nm/journal/vaop/ncurrent/fig_tab/nm.1795_F3.html
http://in.news.yahoo.com/139/20080731/936/thl-scientists-identify-potent...
http://news.med.cornell.edu/wcmc/wcmc_2008/07_29_08.shtml