The Role of the Thymus in the Development of T-Cells

Abstract

The crucial role of the thymus in the generation of T lymphocytes has been suspected for some time. Experiments carried out over 25 years ago, showed that neonatal thymectomy in rodents results in severe immune deficiency (Miller and Osoba, 1967). These results were confirmed in an analysis of mice homozygous for the nude gene where an association between immune deficiency and defective thymic development was shown (Pantelouris, 1971). In patients, the rare condition of thymic aplasia (di George syndrome) results in severe immune deficiency. When separate populations of T and B lymphocytes were identified, it became clear that the thymus is important for the generation of T lymphocytes. Absence of the latter leads to a functional deficiency in immune responses.