Researchers Identify Gene Linked to Similar Disease in Mice.(autoimmune disease gene in mice resembles systemic lupus erythematous)

2001 FEB 15 - (NewsRx.com) -- Researchers at the University of California, San Diego (UCSD), School of Medicine have identified a gene in mice that causes an autoimmune disease remarkably similar to human systemic lupus erythematous (SLE, or lupus).

According to the Lupus Foundation of America, SLE affects nearly one million people in the United States. Ninety percent of these are women, with a high percentage African Americans and Hispanics. Characterized by an immune system gone wild. SLE damages organs such as kidneys, liver, brain, heart, spleen, joints, and lungs.

In the January 30, 2001. issue of the Proceedings of the National Academy of Sciences, the UCSD investigators reported that a SLE-like systemic autoimmune disease in mice is caused by a genetic mutation in an enzyme called alpha-mannosidase II. The enzyme is key to the formation of cell-surface carbohydrate structures called N-glycans, which are involved in the immune response recognition of self verses non-self.

When functioning normally, the human immune system circulates white blood cells called lymphocytes throughout the body, looking for a nd destroying invading pathogens such as bacteria, viruses and toxins. Autoimmune diseases such as arthritis, multiple sclerosis and SLE occur in about 5% of the population when a person's own immune system fails to recognize cells of the body and attacks normal organs and tissue.

Despite the prevalence of autoimmune disease, the inherited genetic susceptibilities and causes are not known. In SLE patients, for example, the lymphocytes appear normal, and yet the patients' tissues and organs are ravaged by an attacking immune system.

Over the years, researchers have noted a correlation between changes in N -glycans, or carbohydrate structure, and the presence of autoimmune disease, according to UCSD cellular and molecular medicine professor Jamey D. Marth, PhD, who is the senior author of the PNAS paper and a Howard Hughes Medical Institute associate investigator.

Also a member of UCSD's Glycobiology Research and Training Center, Marth has long been interested in the role that cell-surface carbohydrates, or glycans, play in disease. ...