the role of t regulatory lymphocytes in lymphoma

t regulatory cells play a crucial role in immunological unresponsiveness to self- antigens and in suppressing excessive immune responses deleterious to the host. t regulatory cells are produced in the thymus as a functionally mature subpopulation of t cells. they can be induced from naive t cells in the periphery and express their marker as a forkhead/winged helix transcription factor called foxp3. in patients with lymphomas where t regulatory cells serve as suppressor anti-tumor cytotoxicity, decreased numbers of t regulatory cells are associated with a favorable prognosis. in contrast, in patients with lymphomas where t regulatory cells function as anti-tumor cytotoxic agents, enhanced numbers of t regulatory cells are associated with a favorable prognosis. tumors actively promote the accumulation of these cells through several mechanisms that involve activation of naturally occurring t regulatory cells as well as conversion of non-t regulatory cells into t regulatory cells. tumor-derived prostaglandin e2 can increase t regulatory cell activity and induce a regulatory phenotype in cd4+cd25+t cells. on the other hand, a balance between t regulatory and th17 cells is essential for maintaining homeostasis of anti-tumor immunity. accelerating processes such as increasing the amounts of il-6 or il-17 can enhance foxp3 t regulatory cell expression and result in a lymphoma or inactivation of t cell cd4+. this effect is the reason for malignancy and a reduction in anti-tumor immune response. in this systematic review we intend to analyze this relationship. we have collected and analyzed the majority of recently published articles on the role of t regulatory cells as a review article.