A team of UniformedServicesUniversity of the Health Sciences (USU) researchers led by Dr. Brian Schaefer, Associate Professor in USU’s Department of Microbiology and Immunology, has demonstrated that the “POLKADOTS signalosome” (named for its dot-like appearance in cells) activates a protein called “NF-kappaB” in T cells. A signalosome is a cluster of proteins that works together inside a cell to control the activity of other proteins. NF-kappaB is a protein that turns on many different T cell functions, including those that contribute to autoimmunity and rejection of transplants. Dr. Schaefer’s team, including lead author, Dr. Suman Paul, had previously shown that the POLKADOTS signalosome, in addition to activating this protein, also limits how much NF-kappaB is turned on. Because the POLKADOTS signalosome is a major point of control for NF-kappaB activation, it may be an attractive target for the design of new drugs to block or regulate T cell functions. Normally, T cells play a key role in maintaining health, by helping to eliminate invading disease-causing bacteria and viruses. However, in some individuals, T cells begin to react against tissues in the body, causing autoimmunity. Also, when a patient receives an organ transplant, T cells will react to that organ and cause transplant rejection, if T cell functions are not successfully blocked. There are currently only a small number of drugs available to treat autoimmunity and transplant rejection, and these drugs do not work for all patients. Inhibiting NF-kappaB activation has long been recognized as a potentially useful strategy for blocking the T cell responses that cause autoimmunity and transplant rejection. However, because NF-kappaB is necessary for a wide variety of important processes throughout the body, directly targeting this protein would lead to many undesired and harmful side effects. Importantly, Dr. Schaefer’s group predicts that drugs that block the activity of the POLKADOTS signalosome would inhibit NF-kappaB only in T cells. This is because the POLKADOTS signalosome appears to be present only in T cells. If successfully produced, drugs that act on the POLKADOTS signalosome may be a powerful new therapy for the treatment of many different autoimmune diseases and transplant rejection.
http://www.sciencedaily.com/ Science Daily
June 10, 2014
http://www.sciencedaily.com/releases/2014/05/140513091117.htm Original web page at Science Daily