Researchers from Mount Sinai School of Medicine have found a new mechanism that explains how certain immune cells are activated to create protective antibodies against infections or pathological antibodies such as those present in autoimmune diseases like lupus and rheumatoid arthritis. The research is published online in the September issue of Nature Immunology.

Autoimmune diseases like lupus and rheumatoid arthritis are characterized by exaggerated production of molecules that activate the adaptive immune system and abnormal antibodies, which attack normal cells causing inflammation and tissue damage. This exaggerated production may occur partly as a result of abnormally strong signaling from TACI via MyD88. By analyzing cells and tissues from immunodeficient patients and genetically engineered mice, Dr. Cerutti's team found a previously unknown interaction between TACI and MyD88 that is important for the production of antibodies against infectious agents. Yet, the same interaction may cause the exaggerated immune response in people with autoimmune diseases.

"Our discovery provides a novel specific target, the signaling pathway between TACI and MyD88, to block the overreaction of the immune system and tissue damage in individuals with autoimmune disorders," said Dr. Cerutti. "We look forward to studying this discovery further and developing therapeutic targets that will inhibit the interaction between TACI and MyD88, preventing autoimmune diseases from progressing with fewer side effects than currently prescribed treatments."

Dr. Cerutti's team collaborated with other researchers at Mount Sinai School of Medicine, including Charlotte Cunningham-Rundles, MD, Professor of Medicine and Pediatrics, and Huabao Xiong, PhD, Assistant Professor of Medicine.

According to the National Women's Health Information Center, autoimmune diseases impact 23.5 million Americans. Common examples include lupus, in which the immune system attacks the skin and/or several organs within the body; rheumatoid arthritis, in which the immune system attacks joints; multiple sclerosis, in which the immune system attacks the nervous system; and Type 1diabetes, in which the immune system attacks insulin-producing cells in the pancreas.

Source: The Mount Sinai Medical Center