Mesenchymal stem cells have two unique and powerful properties that make them the focus of intense scientific research. First, mesenchymal stem cells can escape recognition by the immune system. In other words, when mesenchymal stem cells are infused into the body, the immune system does not recognize them as foreign and does not react to them. If the immune system did respond to the stem cells, it would cause an aggressive and potentially deadly allergic or immunologic response. Second, mesenchymal stem cells have the power to inhibit the immune system. This means mesenchymal stem cells could be used to treat immunological and autoimmune diseases such as Rheumatoid Arthritis, Systemic Lupus Erythematosus, Multiple Sclerosis, and Crohn’s Disease, among others. In essence, mesenchymal stem cells can affect the immune system without triggering an inflammatory response making them an ideal treatment for these diseases.
For some time, mesenchymal stem cells extracted from bone marrow were thought to be the only type of mesenchymal stem cells capable of beneficially affecting the immune system. This fact is not necessarily bad, but it does mean that mesenchymal stem cell donors must undergo a bone marrow procedure, which can be painful and expensive. It would be far better if doctors could use mesenchymal stem cells taken from easier-to-get tissues such as fat (adipose), umbilical cord blood, or Wharton’s jelly (umbilical cord tissue). Most people have adequate amounts of fat just under the skin, and umbilical cord blood and tissue are thrown away as medical waste every day.
Fortunately for patients, Dr. Yoo and colleagues showed that mesenchymal stem cells taken from fat tissue, umbilical cord blood, and Wharton’s jelly exhibit the same immunomodulatory properties as mesenchymal stem cells taken from bone marrow. The researchers showed that these types of mesenchymal stem cells were able to suppress T-cell proliferation as effectively as those cells taken from bone marrow. T-cell proliferation, it should be pointed out, is a key step in autoimmune inflammation that occurs in diseases such as rheumatoid arthritis and others.
In short, mesenchymal stem cells taken from easier-to-get tissues were just as effective at suppressing inflammation (in vitro) as those taken from bone marrow. These results will need to be confirmed in clinical studies; however, this approach will be much more convenient and less expensive for patients and donors if they can use mesenchymal stem cells taken from fat or umbilical cord rather than bone marrow and yet reap the same benefits.
Reference: Yoo KH et al. (2009). Comparison of immunomodulatory properties of mesenchymal stem cells derived from adult human tissues. Cell Immunology. 2009;259(2):150-6.
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