The Immune Mechanism Of Multiple Sclerosis

Multiple sclerosis (MS) is a central nervous system demyeliating disease, characterized by various clinical manifestation and various treatment reaction, various treatment terms, so its path physiology should be various, too. As we all know, its causes include virus infection, immune dysfunction, genes and environment. This review mainly focuses on immune dysfunction part, which is most widely studied and interested in.Now we know that osteopontin plays a part in the relapse of MS, while crystallin plays a part in the remission of MS. Sphingosine-1-phosphate(S1P)receptors belong to the G-protein couples receptor family, including S1P (1-5), which function in modifying the function of the cells, for example:survival, proliferation and metastasis. FTY720 is one of the immune modifying drugs and is effectively used in the MS treatment. Before, we suppose the Th1/Th2 imbalance might be the causes of this disease, but more and more evidences have shown that the Th17/Treg imbalance can better explain the causes of this disease. B cells are professional antigen presenting cells. B cells promote the activation of T cells, maintain the secondary immune responses of the memory T cells and can become plasma cells to secrete antibodies. More and more evidence show that B cells can aggregate into lymphoid-like structures in target organs. Serafini and his colleagues prove that in the ménages of secondary progressing MS patients there are ectopic lymphoid follicles, full of B cells and plasma cells.Microglia cells express all kinds of Toll-like receptors, which is important for the nervous immune responses. The probable immune inflammatory mechanism is that injured nerves are phagocytized leads to more myelinated injury, which then leads to more phagocytation of injured nerves. But microglia cells can secrete anti-inflammatory factors like IL-10, TGF-beta. They also have a special kind of receptors–TREM2, which lies on the surface of macrophage cells, and it correlates to the function of ameliating inflammatory responses and promote the phagocytation. So we see that the microglia cells are two-side swords.Nowadays we know that the three systems-nervous, endocrine and immune–have some chemical signal molecules as common language to carry on frequent information communication. They negotiate with each others to comprise a whole net system. These three systems secrete information substance to pass within the body fluid and act on their own receptors, and this is the key factor in adjusting within systems. In the body of MS patients, the HPA axis is active. Dex-CRH test proves that it positively correlated with disability and cognitive impairment and the atrophy showed in MRI. This test also can be an indicatris to evaluate the prognosis.This review selectively summarizes the immune mechanism of MS, including T cell of adaptive immunity and microglial cells, astrocytes, NK cells, NK-T cells of innate immunity. Also it summarizes how the endocrine changes may relate to the immune mechanism of MS. Can we improve the quality of the drugs being used and under research, is there any probable new target? We need further investigation.