T lymphocytes mature in the thymus to become functional T cells. Studies with chimeric mice and T cell receptor (TCR) transgenic (tg) mice have indicated that the major histocompatibility gene complex (MHC) of thymic radio-resistant (presumed to be epithelial) cells positively select the MHC-restricted T cell repertoire. Surprisingly, mice without a thymus reconstituted with an MHC-incompatible...

The thymus, the site of origin of T cell immunity, shapes the repertoire of T cell reactivity through positive selection of developing T cells and prevents autoimmunity through negative selection of autoreactive T cells. Previous studies have demonstrated an important role for the thymus not only in central deletional tolerance, but also in the induction of peripheral tolerance by vascularized ...

A substance possessing antimycobacterial activity under certain conditions in vitro has been prepared from aqueous extracts of calf thymus. Chemical studies have demonstrated that the activity of this substance is due to a basic peptide or a mixture of basic peptides. Although this thymus fraction has been shown to be essentially free of compounds other than peptides, it has not been obtained i...

Understanding the mechanisms of thymus regeneration is necessary for designing strategies to enhance host immunity when immune function is suppressed due to T cell depletion. In this study, expressed sequence tag (EST) analysis was performed following generation of a regenerating thymus cDNA library to identify genes expressed in thymus regenerati...

AIMS Thymus is the central lymphatic organ in humans with important endocrine function that is involved in maturation of immunocompetent T-lymphocytes. In our study we investigated the relationship among thymus size and the anthropometric dimensions as well as between thymus size and the number of lymphocytes in peripheral blood in full-term newborns. METHODS The examined group consisted of 2...

Implantation of pieces of human fetal liver and thymus into SCID mice results in the development of a human thymus-like organ, in which sustained lymphopoiesis is reproducibly observed. In this model, T cell development can be experimentally manipulated. To study the influence of thymic selection on the development of the human T cell repertoire, the T cell receptor (TCR) V beta gene repertoire...

Thymectomy at 3-4 days of age prevented the induction of leukemia by virus in WF rats; grafts of neonatal thymus cor rected this deficiency. Multiple thymus grafts were much more effective than single ones. Similarly, thymectomy in rats caused a lasting reduction of lymphocyte levels and the capacity to produce hemagglutinins; these deficiencies were also corrected by thymus grafts. In restorin...

OBJECTIVE Tissue-specific self-antigens are ectopically expressed within the thymus and play an important role in the induction of central tolerance. Insulin is expressed in both pancreatic islets and the thymus and is considered to be the primary antigen for type 1 diabetes. Here, we report the role of the insulin transactivator MafA in the expression of insulin in the thymus and susceptibilit...

The total tissue nucleic acids (DNA and RNA) have been isolated from normal and neoplastic mouse thymus glands and chromatographically fractionated. Significant differences in the chromatographic distribution of the nucleic acids from normal adult thymus and x-radiation-induced thymic lymphosarcoma were found. Chromatographic patterns intermediate between normal and tumor were found in the thym...

A characteristic of the normal thymus gland is its rapid growth during the early stages of life followed by a progressive involution as the animal ages. On the other hand, in the Akr strain of mice a marked hyperplasia of this gland usually occurs in those animals which develop lymphatic leukemia. In this strain the thymus is believed to be the primary site of leukemogenesis (6). In the followi...