Neuroendocrine and viral correlates of premature immunosenescence.
Aging continuously remodels the immune system, a process known as immunosenescence. Here, we review evidence of premature immunosenescence in younger individuals under conditions of chronic psychological stress, chronic inflammation, or exposure to certain persistent viral infections. Chronic stress may accelerate various features of immunosenescence by activating key allostatic systems, notably the hypothalamic-pituitary-adrenal axis and increased cortisol levels. Chronic stress is associated with thymic involution, blunted T cell proliferation, increased serum proinflammatory markers, and shorter telomere lengths. Human cytomegalovirus (CMV) infection has been implicated in accelerating immunosenescence by shrinking the T cell receptor repertoire and causing clonal expansion of senescent CD8(+) CD28(-) T cells with a proinflammatory profile. These factors increase inflammation associated with aging, or "inflammaging," particularly as it relates to etiology of several age-related diseases and increased mortality. Patients with rheumatoid arthritis have been shown to have several signatures of premature immunosenescence, including expansion of senescent T cells associated with cognitive impairment. We end by speculating that bipolar disorder can be considered as a model of accelerated aging because it has been associated with shortened telomeres, higher CMV IgG titers, and expansion of senescent and regulatory T cells.
['Bauer|Moisés E|ME|', 'Wieck|Andrea|A|', 'Petersen|Laura E|LE|', 'Baptista|Talita S A|TS|']
D001172:Arthritis, Rheumatoid D001714:Bipolar Disorder D016922:Cellular Senescence D020805:Central Nervous System Viral Diseases D003587:Cytomegalovirus D003586:Cytomegalovirus Infections D005938:Glucocorticoids D006801:Humans D007030:Hypothalamo-Hypophyseal System D000068884:Immunosenescence D007249:Inflammation D008213:Lymphocyte Activation D009490:Neurosecretory Systems D010913:Pituitary-Adrenal System D011948:Receptors, Antigen, T-Cell D013315:Stress, Psychological D013601:T-Lymphocytes
immunosenescence aging psychological stress cytomegalovirus glucocorticoids lymphocytes