Immune system drug targets identified

U.S. researchers have developed a method for finding molecular targets of the immune system that could help isolate disease causes and make new medicines.

The researchers, at the National Jewish Medical and Research Center, said the targets, known as antigens, could have broad applications in biological and medical research. For example, the team has been collaborating with other researchers looking for causes of rheumatoid arthritis and developing cancer vaccines.

The team focused on T-cells, the sentinels of the immune system. T-cells circulate in the body looking for infectious organisms and each T-cell carries a receptor that can recognize a specific protein fragment.

Cells known as antigen-presenting cells carry these protein fragments on their surfaces bound to a molecule known as MHC. When a T-cell encounters MHC, it binds to it and becomes activated, which in turn tells the immune system to attack that protein fragment and its parent organism.

Using genetic tools, the researchers created a small ocean of cells, each carrying a single MHC molecule holding a specific protein fragment. They then fished in this ocean with T-cell receptors containing fluorescent tags. When the receptors found MHC, the researchers isolated the cells displaying them.