Critically evaluate the evidence suggesting that mTOR inhibitors can Essay

Critically evaluate the evidence suggesting that mTOR inhibitors can help induce tolerance to foreign antigens and discuss the i - Essay Example It integrates the cell signals that give information about the energy status of the cell, nutritional status, mitochondrial potential, oxygen tension, aminoacids, ATP, and growth signals. During nutritional deficiency, the mTOR signaling becomes active and increases the protein synthesis and increases the cell size. If something is lacking inside the cell, then mTOR will decrease the protein synthesis and thus decreases the cell size and there by reduces the energy expenditure of the cell and prevents cell proliferation. The mechanical induced overload-hypertropy is due to the mTOR and their activity is inhibited by the introduction of Rapamycin. (Polunovsky and Houghton, 2010). Immune system consists of many types of regulatory cells. The regulatory cells contribute to the immune tolerance and immune homeostasis through many different mechanisms. The manipulation of these cells therapeutically to improve the transplant tolerance has become the most important field of interest nowada ys. The important subsets of T cells are the CD4 (helper T cells) and CD 8 (Cytotoxic T cells) cells. Of these two types, CD4 T cells are called as regulatory or suppressor T cells. These cells are responsible for the immune toleran ce. (Fernandez 2010). These cells instead of increasing the immune response, decreases it there by enabling the transplant to get adapted to the body. They play an important role in auto immune reaction. The balance between the regulatory and the effector T cells are much necessary for the immune response and also for the controlling of many diseases. The developments of these regulatory cells are mediated by the mammalian target of rapamycin signaling protein. (mTOR protein complex). Rapamycin is isolated from the soil bacterium Streptomyces hygroscopicus. Rapamycin is commonly used as the immune suppressive drug in the transplant recipients and also found to inhibit the intracellular kinase of mTOR. (Polunovsky and Houghton, 2010). mTOR the check point protein kinase was found to have a major effect on the cell proliferation and growth, it is also found to have many downstream targeting based on phosphorylation of the protein. The major inputs for this protein are obtained from the growth factors and growth hormones such as insulin, IGF-1 and IGF-2 and some extracellular amino acids. (Polunovsky and Houghton, 2010).mTOR can also identify the status of the energy requirements and the redox level of the cell. Considerable progress has been made in understanding the signaling network only after the identification of the mTOR protein kinase. If this pathway is dysregulated in the human system, it leads to certain diseases in the human, most importantly some cancers. So a detailed study about the protein is very important. mTORs are high molecular weight molecules with many conserved structural domains. They contain 2549 amino acids with N-terminal containing 20 tandem HEAT repeats. (Hay and Sonenberg 2004). mTOR contains two protein complexes mTORC1 and mTORC2. mTORC1 is the main upstream centre for growth factors, stress signals and nutrients. They also help to convert the anabolic and catabolic pathways of the cell for the normal functioning. The mTORC1 cell signaling is high associated with the human cancer. The signaling network of the mTOR contains many oncogenes such as EGFR, PDGFR, PI3K, Ras, Raf, S6K1, Akt and tumor suppressors such as PTEN, LKB1, PDCD4, NF1 and REDD1. (Polunovsky