Regulation
The outcome of autoimmune activity is determined by several factors, namely: the intensity, the location, and the duration of the autoimmune response. For an autoimmune response to be beneficial, its intensity, duration and site of activity must be tightly regulated. Although autoimmune T cells exist in all healthy individuals, a relatively small portion of the population develops autoimmune diseases. This is due to various mechanisms that constantly regulate the activity of autoimmmune cells. One of the prominent autoimmune regulatory mechanisms is a sub-population of T cells called ‘regulatory T cells’ (previously known as ‘suppressor T cells’), which restrict autoimmune activity. Experiments in animal models of CNS injury have shown that depletion of regulatory T cells allows an enhanced neuroprotective autoimmune response to take place after the insult. Importantly, however, such an experimental manipulation can at the same time increase the susceptibility to development of an autoimmune disease. Under certain conditions, an initially protective autoimmune response can reach a tipping point, after which it will have a detrimental effect on the tissue, and might even develop into an autoimmune disease. Both genetic and environmental factors (such as infection) can underlie such a transition from a neuroprotective autoimmune response into an overwhelming and detrimental autoimmune disease.
Other cell types, such as B cells and even neural progenitor cells, can promote regulation of immune response in the CNS. Stem and progenitor cells are usually regarded with respect to their potential to serve as a source for newly differentiated cells, but recently stem and progenitor cells have also been acknowledged for their ability to modulate immune activity. Experiments have shown that injection of neural progenitor cells into the brain’s ventricles can modulate an immune response taking place at multiple inflammatory foci in a mouse model of multiple sclerosis, or at a single site at the injured spinal cord.
Read more about this topic: Protective Autoimmunity
Famous quotes containing the word regulation:
“Lots of white people think black people are stupid. They are stupid themselves for thinking so, but regulation will not make them smarter.”
—Stephen Carter (b. 1954)
“Nothing can be more real, or concern us more, than our own sentiments of pleasure and uneasiness; and if these be favourable to virtue and unfavourable to vice, no more can be requisite to the regulation of our conduct and behavior.”
—David Hume (1711–1776)
“Nothing changes my twenty-six years in the military. I continue to love it and everything it stands for and everything I was able to accomplish in it. To put up a wall against the military because of one regulation would be doing the same thing that the regulation does in terms of negating people.”
—Margarethe Cammermeyer (b. 1942)