Scientists from UCLA and Harvard School of Medicine have successfully discovered how the body's immune system fights in limiting the control of infections like leprosy in some cases but not in others.
The research says that the body's initial immune system often fights with the infections in the initial stages and sometimes succeeds in controlling them. Only when they are unable to control the bug that it spreads to cause maximum infection.
The researchers had isolated immune cells in the blood from healthy people and exposed them to a component of mycobacteria. The immune cells, also known as monocytes, have immediately divided into two distinct forms, as an emergency response to the bacterial invasion. The first set of cells, called macrophages, seeks out and engulfs the bacterial cells. The second set of cells, called dendritic cells, helps in causing a second immune response called adaptive immunity.
When infected with two kinds of leprosy bacteria, the first bacteria was attacked and killed by both the sets of immune cells that formed as soon as the bacteria was detected by the immune cells. For the stronger form of leprosy bacteria, monocytes had not been able to produce key anti-bacterial fighters or the antigen-presenting dendritic cells.
The study brings to light exactly how the immunity of the body works or fails to work when attached with a foreign infection.
Reference: Harvard School of Public Health, Press Release, May 2005