Many of us would have heard of L-Tryptophan, the amino acid present in turkey which is (falsely) blamed for the notorious post-thanksgiving-dinner drowsiness; however, now this amino acid has stepped into the limelight. Recent research has found the amino acid to be linked to the functioning of the immune system and it is currently being used in trials for multiple sclerosis treatments.
The research that has led to these discoveries has been undertaken by a renowned professor of neurological sciences, Steinman, MD and his team. Steinman is one of the top experts in the functioning of the human brain and nervous system and related diseases and is also chair of the immunology program. His focus usually lies on technologically-advanced, genetic treatments; so work on the effects of an amino acid was an unusual project for him to have taken on.
In fact, Steinman only considered this project because Michael Platten, MD, PhD, a leading postdoctoral researcher in the field of this amino acid, approached Steinman with the suggestion of trying tranilast in his multiple sclerosis studies. Tranilast is an anti-allergic medication that is a derivative of the amino acid. Platten had his own source of funding through Angiogen Pharmaceuticals, so Steinman felt there was nothing to lose.
The Link Between Diet And Immunity
Multiple sclerosis affects over 2.5 million people world-wide. It is a disease where, the immune system attacks the protective layer of cells that surround neurons in the central nervous system. The symptoms of this disease can be relieved by suppressing the immune system.
Platten, together with Pegg Ho, PhD – a postdoctoral researcher in Stainman’s team – experimented using mouse cells and a form of multiple sclerosis known as experimental autoimmune encephalomyelitis (EAE). They compared the effects of four metabolites of the amino acid as well as tranilast, on the disease. (When an amino acid is broken down by the body, molecules called metabolites are formed.) All of them worked to suppress the immune system and reduce the symptoms that the mice were experiencing.
The importance of this finding lies in the proof of the link between diet and immunity. Up until now there has been no noteworthy evidence of any connection, but these findings have opened new paths for research into the effects of diet on immunity.
Furthermore, they found that if they took immune cells from mice that had been protected with treatment and injected them into the mice with EAE, the protection was also transferred. This result could mean that the treatment activates regulatory T cells which are responsible for suppressing the immune system. However, this is still not fully understood.
These significant discoveries on the positive benefits of this amino acid are to be discussed in Steinman’s latest paper which is due for release in the Nov. 4 issue of Science.
As to whether eating certain foods will ultimately cure autoimmune diseases, there is no definite answer; however, using medication such as tranilast which has the effects of the natural amino acid, but in a form that is, at this stage, more easily assimilated by human body, may currently be the most efficient way of suppressing the immune system.