Vit D and T Cells at Vitamin D World Mar 2010
Vitamin D Breakthrough, 
New data explains the role of Vitamin D in multiple conditions.
March 15th 2010  http://www.vitamind3world.com/NewsFlash.html 
Scientists at the University of Copenhagen have discovered that Vitamin D is crucial to activating our immune defenses and that without sufficient intake of Vitamin D, T-cells, the killer cells of the immune system will not be able to react to and fight off serious, life-threatening infections in the body.
- "We have discovered that the first stage in the activation of a T cell involves Vitamin D," explains Professor Carsten Geisler from the Department of International Health, Immunology and Microbiology." When a T-cell is exposed to a foreign pathogen, it has an immediate biochemical reaction and extends a signaling device or 'antenna' known as a Vitamin D receptor with which it searches for Vitamin D. This means that the T-cell must have Vitamin D or activation of the cell will cease. If the T cells cannot find enough Vitamin D in the blood, they won't even begin to mobilize."
T-cells that are successfully activated transform into one of two types of immune cell. They either become killer cells that will attack and destroy all cells carrying traces of a foreign pathogen, or they become helper cells that assist the immune system in acquiring "memory." The helper cells send messages to the immune system, passing on knowledge about the pathogen so that the immune system can recognize and remember it at the next encounter and launch a more efficient and enhanced immune response. T-cells form part of the adaptive immune system, which means that they function by teaching the immune system to recognize and adapt to constantly changing threats.
Identifying the role of Vitamin D in the activation of T-cells is a major breakthrough.
- "Scientists have known for a long time that Vitamin D is important for calcium absorption and the vitamin has also been implicated in diseases such as cancer and multiple sclerosis, but what we didn't realize is how crucial Vitamin D is for actually activating the immune system - which we know now."
The discovery, the scientists believe, provides much needed information about the immune system and will help them regulate the immune response. This is important not only in fighting disease but also in dealing with anti-immune reactions of the body and the rejection of transplanted organs.
Active T-cells multiply at an explosive rate and can create an inflammatory environment with serious consequences for the body. After organ transplants, e.g. T-cells can attack the donor organ as a "foreign invader." In autoimmune disease, hypersensitive T-cells mistake fragments of the body's own cells for foreign pathogens, leading to the body launching an attack upon itself.
The research team was also able to track the biochemical sequence of the transformation of an inactive T-cell to an active cell, and thus they could intervene at several points to modulate the immune response. Inactive or 'naïve' T-cells crucially contain neither the Vitamin D receptor nor a specific molecule (PLCgamma1) that would enable the cell to deliver an antigen-specific response.
"The findings," continues Professor Geisler, "could help us to combat infectious diseases and global epidemics. They will be of particular use when developing new vaccines, which work precisely on the basis of both training our immune systems to react and suppressing the body's natural defenses in situations where this is important, as is the case with organ transplants and autoimmune disease."
Ref:Vitamin D controls T cell antigen receptor signaling and activation of human T cells, Nature Immunology, Published online: 7 March 2010 ,Marina Rode von Essen1, Martin Kongsbak1, Peter Schjerling2,4, Klaus Olgaard5, Niels Ødum1,3 & Carsten Geisler1