Stress-related neuroimmunomodulation of monocyte-macrophage functions in HIV-1 infection

Monocytes/macrophages play a central role in the afferent and efferent limbs of the immune system. Macrophages perform several immunological functions both in vivo and in vitro, including antigen presentation, tumor cell killing, phagocytosis, and bacterial and viral killing. Acquired immunodeficiency syndrome (AIDS), a disease characterized by a profound immunodeficiency, induces a wide range of neuropsychological abnormalities. The occurrence of severe psychological disturbances, including stress, depression, and anxiety increase psychological and physical indices of morbidity among patients. Stress influences several immunological responses in man and animals and is usually accompanied by altered blood levels of various CNS-related peptides or neurohormones. Monocytes/macrophages express surface receptors for different CNS-secreted molecules. In ARC and AIDS patients abnormal neuropeptide levels may be related to severe psychological disturbances. Neuropeptides and neurohormones may play a central role in stressed HIV-1-infected patients by affecting monocyte-macrophage functions, which may further trigger disease progression and immunologic deficiency. It is hypothesized that stress reactions lead to altered release of neurohormones and/or neuropeptides which affect monocyte-macrophage functions and favor progression of HIV-1-related disease.