2008 General Immune System Function
With LRI funding, Dr. Reeves set out to test the effectiveness of using a population of adult stem cells called “mesenchymal stem cells” to treat lupus. These cells, which scientists have studied in great detail and know how to grow in the laboratory, can generate many different varieties of other cells: muscle, fat, bone, tendon, skin, and more.
But while researchers understand how to manipulate mesenchymal cells, they have not been used them to down-regulate autoimmunity. This highly novel concept represents a whole new approach to suppressing the overactive immune system that can cause such destruction in lupus and other autoimmune illnesses.
To find out how lupus inflammation damages the bone marrow, Dr. Reeves’ group studied bone marrow biopsies from lupus patients. They found lupus patients had abnormally high numbers of dying cells and that the bone marrow was peppered with cells producing a molecule called tumor necrosis factor (TNF) that can kill other cells.
He and his team went on to conduct a study of mice with lupus to find out if TNF causes the death of stem cells responsible for producing new blood cells. Like lupus patients, the mice had high numbers of dying cells and TNF producing cells in their bone marrow as well as anemia. Mice deficient in the TNF gene or in the inflammatory pathway leading to TNF production did not have bone marrow damage or develop anemia. Their results confirmed that problems with blood cell production in the bone marrow are caused by the lethal effects of TNF on stem cells.
Potential for Treating Anemia
Dr. Reeves explained “Our study strongly suggests that TNF production is behind some of the bone marrow problems in lupus, including anemia. TNF inhibitors, which are used to treat rheumatoid arthritis, might therefore benefit certain lupus patients with persistent low red blood cell counts.”
Further research is needed to determine if these drugs can be used safely in lupus and if they are effective treatment for anemia caused by lupus.