TB bacterium uses its sugar coat to sweeten its chances of livin...(ied to specific regions of the world bas...)

This newest research appears online in the Journal of Biological Chemistry.

To maintain ideal breathing conditions, the lungs avoid inflammation. They do this by trying to minimize immune responses to various particles humans inhale because the more the immune system responds, the higher the level of inflammation that results.

Too much inflammation can interfere with the ability to breathe.

"Then here comes TB, an organism that gets into an environment that is not very primed to respond to a foreign invader, and the TB fundamentally takes advantage of that environment," Schlesinger said.

About 2 billion people worldwide are thought to be infected with TB bacteria. People who are infected can harbor the bacterium without symptoms for decades, but an estimated one in 10 will develop active disease characterized by a chronic cough and chest pain. An active infection is treated with a combination of antibiotics that patients take for at least six months.

At the point of infection in the lung, TB bacteria are eaten by a macrophage, also called an antigen-presenting cell. As part of what is called the innate immune response, the macrophage activates specific molecules that make pieces of the bacteria visible to infection-fighting T cell warriors, which triggers an eventual T-cell response to come to the macrophage's aid.

The innate response kicks in to fight any pathogen, but an acquired immune response is required to activate T cells that are specifically designed to help macrophages kill TB bacteria. The sugarcoating delays activation of that acquired response, so the bacteria then find comfort in the macrophages, causing a latent infection.

If the immune response is defective and fails to prompt macrophages to kill the TB bacteria, the bacteria eventually multiply so much that t
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