tailieunhanh - Báo cáo y học: "Enhancing versus Suppressive Effects of Stress on Immune Function: Implications for Immunoprotection versus Immunopathology"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Enhancing versus Suppressive Effects of Stress on Immune Function: Implications for Immunoprotection versus Immunopathology. | ORIGINAL ARTICLE Enhancing versus Suppressive Effects of Stress on Immune Function Implications for Immunoprotection versus Immunopathology Firdaus S. Dhabhar PhD It is widely believed that stress suppresses immune function and increases susceptibility to infections and cancer. Paradoxically stress is also known to exacerbate allergic autoimmune and inflammatory diseases. These observations suggest that stress may have bidirectional effects on immune function being immunosuppressive in some instances and immunoenhancing in others. It has recently been shown that in contrast to chronic stress that suppresses or dysregulates immune function acute stress can be immunoenhancing. Acute stress enhances dendritic cell neutrophil macrophage and lymphocyte trafficking maturation and function and has been shown to augment innate and adaptive immune responses. Acute stress experienced prior to novel antigen exposure enhances innate immunity and memory T-cell formation and results in a significant and long-lasting immunoenhancement. Acute stress experienced during antigen reexposure enhances secondary adaptive immune responses. Therefore depending on the conditions of immune activation and the immunizing antigen acute stress may enhance the acquisition and expression of immunoprotection or immunopathology. In contrast chronic stress dysregulates innate and adaptive immune responses by changing the type 1-type 2 cytokine balance and suppresses immunity by decreasing leukocyte numbers trafficking and function. Chronic stress also increases susceptibility to skin cancer by suppressing type 1 cytokines and protective T cells while increasing suppressor T-cell function. We have suggested that the adaptive purpose of a physiologic stress response may be to promote survival with stress hormones and neurotransmitters serving as beacons that prepare the immune system for potential challenges eg wounding or infection perceived by the brain eg detection of an attacker . However this .