Papel dos linfócitos T reguladores no desenvolvimento e controle do sistema imunológico.

Abstract

Immune response is critical to health maintenance, defending body from invading pathogens. This protective system needs to be controlled so that there is exacerbated response and immune cells attack the body. The cells responsible for this control are regulatory T lymphocytes (Treg), which cease the immune response through mechanisms not totally understood. Currently the probable regulatory mechanisms described are suppression mediated by contact of granzyme B and porphyrin produced by Tregs; regulation by factors that mediate the killing of effector cells, such as immune inhibitory cytokines IL-10, TGF-β and adenosine; mechanism that requires direct contact between cells such as binder-receptor, involving ICOS; and described most recently, mechanism that involves cytokine deprivation induced by Treg. Regulatory T cells have been shown to be important in development of cancer in various tissues since patients with ongoing disease showed a high number of Treg in tumor microenvironment, which increased interest in researchers because the activities of this cell population can be an alternative to prevent the proliferation of tumors. Command of suppressor T cell activity is also an alternative therapy for autoimmune diseases which have proved to be directly involved in development of these diseases.