The role of cytokines in the acquired immunodeficiency syndrome.

HIV replication in vitro is regulated by many factors, including various exogeneous stimuli and proteins encoded by either virus or cellular genomes. During the asymptomatic period, cells latently or chronically infected with HIV gradually express virus, leading to immunosuppression and opportunistic infection. These conditions would result in the increased secretion of cytokines, especially TNF, from infected and uninfected cells, which can induce HIV and killing of infected cells. A vicious circle is then set in motion in which heterologous microbial infections directly or indirectly activate HIV and the production of cytokines, thereby accelerating lymphocyte depletion and immunodeficiency. AIDS is a disorder of the immune network caused by a unique retrovirus HIV. However, if the whole story described above is true, this disease can also be termed a “cytokine disease”. Immunity resembles a “doubleedged sword”, with aspects not only protective, but also deleterious to the host. Therefore, it is essential to more extensively investigate the mechanism of cytokine regulation of HIV expression in vivo, not only to understand the complex patohophysiology of AIDS, but also to design a therapeutic strategy to halt this deadly disease.