Scientists at the Scripps Research Institute have discovered the biological trigger for the autoimmune disease lupus. Researchers identified three proteins, called Toll-Like Receptors (TLRs), that can cause the immune system to turn against the body. The study was published June 29 in the Early Edition of the Proceedings of the National Academy of Sciences (PNAS).
The three proteins identified in the study (TLR 3, TLR 7, and TLR 9) reside in a part of the cell called the endolysosome. They detect the DNA and RNA of attacking pathogens, and then stimulate the immune system to produce antibodies. But these proteins can malfunction, causing the immune system to mark its own DNA and RNA as a foreign invader. The most common type of antibodies found in lupus are coded to attack the patient’s own genetic material.
The three TLRs are produced elsewhere inside the cell before being transported to the endolysosome. By switching off the gene that carries the three proteins to the endolysosome, scientists were able to prevent lupus from developing in laboratory mice. This suggests that the TLRs and the transport gene may be central to future lupus therapies. The research team will need to do more testing before developing a treatment for human use.
Several companies are already developing treatments for lupus, which affects approximately 1.5 million people in the U.S. Companies working in this area include Genelabs Technologies, Human Genome Sciences, Watson Pharmaceuticals, VLST Corporation, and La Jolla Pharmaceutical Company.
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