(Inside Science TV) -- There are 633,000 homeless people in America, many of whom have a high risk of contracting tuberculosis, a lethal disease that attacks the lungs. In Los Angeles' Skid Row neighborhood alone, more than 4,500 people have been exposed to tuberculosis, or TB. Now, scientists at the UCLA School of Medicine have uncovered a medical mystery that may help the homeless in the United States and millions across the globe.
“[Tuberculosis] is a very contagious disease. It’s something you can catch in the elevator. If someone coughs, they can spread the bacteria to you,” said Dr. Robert Modin, a microbiologist at UCLA.
TB is difficult to fight mainly because it has learned to hide out in the body disguised as a virus. “These bacteria are wolf in sheep’s clothing and the immune system is tricked in how it detects it,” explained Dr. Modin.
Normally, the immune system releases a protein called interferon gamma when it detects bacteria in its system. The interferon gamma helps to destroy the invading bacteria. But UCLA's researchers found that when bacteria act like viruses, the immune system is fooled into launching an attack using a different protein called interferon beta, which is designed to kill viruses, not bacteria. Undeterred by the interferon beta, TB bacteria can grow and multiply without being attacked by the immune system.
Modin said, “The immune response thinks it’s dealing with a virus instead of the bacteria and in doing that it shuts off the hosts mechanisms to kill the bacteria.”
TB kills 1.4 million people worldwide each year and is very similar to the bacterium that causes leprosy, which continues to affect hundreds of thousands of people around the globe. Scientists are hopeful that this discovery will improve the treatment of both diseases.
Now that scientists know TB's secret and have been successful in stopping TB in the lab, they hope to stop it in people.
Get inside the science: