A recent study conducted by the Forsyth Institute has shown that latent Tuberculosis (TB) bacteria uses the low oxygen (hypoxia) niches in bone marrow stem cells to hide from the immune system.
This makes the latent TB bacteria secure within the body because immune cells and toxic chemicals alike are incapable of reaching this area. Additionally, the hypoxia-activated cell signaling pathways may protect the bacteria stem cells from aging or dying. The Mycobacterium tuberculosis (Mtb), which causes TB, use this to their advantage.
Approximately 2.2 billion people around the world are infected with Mtb, and approximately 1.7 million people die each year from TB infections.
"From our previous research, we learned that cancer stem cells reside in the hypoxic zones to maintain self-renewal property, and escape from the immune system,” Bikul Das, MBBS, Ph.D., associate research investigator at the Forsyth Institute and honorary director of the KaviKrishna laboratory in Guwahati, India, said. "So, we hypothesized that Mtb, like cancer, may also have figured out the advantage of hiding in the hypoxic area."
attribute these large numbers to the fact that TB can remain dormant
within a body and later manifest as a disease.
"These findings now explain why it is difficult to develop vaccines against tuberculosis," Das said. "The immune cells activated by the vaccine agent may not be able to reach the hypoxic site of bone marrow to target these 'wolves-in-stem-cell-clothing.'"
Further details are available online in the American Journal of Pathology.