Immune-mediated mechanisms, role

Mechanism of Action. Tacrolimus acts like cyclosporine by binding to a specific protein (calcineurin) in lymphoid tissues and inhibiting the production of key immune mediators such as IL-2.5 IL-2 plays a critical role in the immune response because this substance promotes the growth and proliferation of activated T... 

This chapter focuses on percutaneous transluminal coronary angioplasty (PTCA), provides a summary of the underlying immune activities of the diseased vasculature, and focuses in part on the role of immune and inflammatory mediators in the restenotic process. In addition, the mechanism of action of sirolimus, the drug used in the first successful DES for reduction of restenosis will be highlighted. Finally, the potential role for immune mediators on the overall processes of atherosclerosis will be explored. 

It is known that ACAID contributes to ocular tumor survival and long-term survival of orthoptic comeal allografts. Some experiments showed that removal of NKT cells prevented the continued acceptance of ocular tumors and caused the elimination of the immune privilege of the eye. Without functioning NKT cells, mice were not able to accept orthoptic comeal allografts for prolonged periods of time (Sonoda et al., 2002). This data demonstrates the essential role of NKT cells in the generation of ACAID. New information about ACAID may lead to application of ACAID mechanisms in prevention and treatment of immune-mediated inflammatory diseases in humans. 

The failure of immunosuppression to ameliorate type-Idiabetes or chronic progressive multiple sclerosis, predominantly immune mediated diseases, invaUdates the role of immune mechanisms in initiating these disorders. 

It is believed that UVR exposure causes skin immune suppression. Both UVB and UVA have been implicated (292). A possible mechanism is UVA-induced lipid peroxidation, which results in the migration of immune-mediating cells from the epidermis and therefore leads to skin immune suppression (224). It has been suggested that skin immune suppression plays a role in carcinogenesis. However, the relationship between the two is not well understood yet (293). 

ABSTRACT In mammals, nitric oxide (NO) is a reactive free radical involved in diverse physiological functions. NO and its redox-related forms NO+ and NO react with di(oxygen) and its derivatives, with metalloproteins and thiol-containing proteins. NO-mediated nitrosation of proteins represents an important cellular regulatory mechanism. Biosynthesis of NO is catalysed by nitric oxide synthase (NOS). Three isoenzymes representing distinct gene products have been identified the inducible NOS isoform, the constitutive neuronal and endothelial isoforms. Inducible and constitutive NOSs have the same structural features, but their activities differ in their dependence to calcium and the rate of NO produced. The principal NO-mediated functions in mammals are endothelium-dependent relaxation, neurotransmission and immune response. The role of NO in the antitumor immune response comprises both regulatory and effector functions at the intra- or inter-cellular level. The first function includes inhibition of lymphocyte proliferation or participation in different transduction pathways. The second fiinction includes pro- or anti-tumoral effects and NO-mediated cell toxicity or cell resistance to apoptosis. 

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