Recirculation of naive T lymphocytes

Abstract

After development in the thymus, naive T lymphocytes come into circulation and continuously recirculate between the blood and peripheral lymphoid organs for activation and transformation into effector cells. The movement of naive T lymphocytes represents an ordered sequence controlled by the expression of specific of specific proteins (selectin, integrin and chemokine) that includes the recruitment of circulating lymphocytes on the luminal surface of the blood vessel, transendothelial transition and migration within the extravascular compartment of peripheral lymphoid organs. The question of the movement of naive T lymphocytes in and out of non-lymphoid organs in physiological conditions has not been fully resolved. There is an opinion that naive T lymphocytes under physiological conditions routinely access almost all non-lymphoid organs for the purpose of immunosurveillance and/or tolerance induction. Non-lymphoid organs burdened by chronic inflammation and tumor processes may possess a significant number of naive T lymphocytes. Organized lymphoid tissue causally contributes to the persistence of certain autoimmune diseases. Recruitment in tumor tissue and subsequent antitumor immune response correspond with a positive prognosis.