Recognition of self-antigens by T lymphocytes is a central event in autoimmunity. Understanding of the molecular interactions between T cell receptors (TCR) and self-epitopes may explain how T cells escape thymic education and initiate an autoimmune reaction. We have studied five human in vivo activated T cell clones specific for the region 535-551 of human thyroid peroxidase (TPO) established ...

Thrombopoietin (Tpo), the ligand for the c-Mpl receptor, is a major regulator of megakaryopoiesis. Treatment of mice with Tpo raises the platelet count fourfold within a few days. Conversely, c-mpl knock-out mice have platelet counts that are 15% that of normal. The subunit structure of the c-Mpl receptor is not fully understood. Some cytokines that stimulate megakaryopoiesis (IL-6, IL-11, leuk...

Thrombopoietin (TPO) is a newly cloned and characterized cytokine that stimulates megakaryocytopoiesis and platelet production.'" Recent studies have shown that TPO speeds up platelet recovery after cytoreductive the rap^^,^ and, thus, holds great potential for the treatment of thrombocytopenia of various etiologies. Human mature TPO is composed of 353 amino acids. The N-terminal 153 amino acid...

The in vivo effect of thyrotropin (TSH) on the intracellular localization of thyroid peroxidase (TPO) in rat thyroid epithelial cells was examined by an indirect immunofluorescence method. The staining for TPO in the epithelial cells of normal rats appeared all over the cytoplasm, especially in the apical region. The injection of propylthiouracil for 3-10 days increased the staining in the apic...

The extraction of rare earth elements (REEs) from nitric acid solution with a triphosphine trioxide (TPO) is presented. Performances of such a ligand in ionic liquids vs. a classical solvent (benzyl ether) are compared. TPO seems to be 10 to 100 times more efficient when it is dissolved in ionic media whatever the concentration of nitric acid involved. Mechanistic investigations reveal that cat...

Experiments were performed to determine whether the absence of the enzyme sys tem tryptophan peroxidase (TPO) in transplanted hepatomas was associated with fac tors other than deletion of the apoenzymes, and whether changes in TPO activity and its adaptive response occurred during carcinogenesis with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). No appreciable TPO activity was observed in tw...

Thrombopoietin (TPO) or MpI ligand is known to stimulate megakaryocyte (MK) proliferation and differentiation. To identify the earliest human hematopoietic cells on which TPO acts, we cultured single CD34+Thy-1+Lin- adult bone marrow cells in the presence of TPO alone, with TPO and interleukin-3 (IL-3), or with TPO and c-kit ligand (KL) in the presence of a murine stromal cell line (Sys1). Two ...

Thrombopoietin (TPO) is the physiologic regulator of platelet production and works by binding to its receptor on megakaryocyte precursor cells, thereby activating a large number of antiapoptotic and cell maturation pathways. "First-generation" recombinant forms of TPO were developed over a decade ago and were found to increase the platelet count in patients undergoing nonmyeloablative chemother...

BACKGROUND AND OBJECTIVE Thrombocytopenia of peripheral origin is basically due to platelet destruction or splenic sequestration. Thrombopoietin (TPO) regulates platelet production stimulating megakaryocyte proliferation and maturation. The evaluation of TPO levels may be a useful tool in the diagnosis of thrombocytopenias of unknown origin. We tried to determine the value of TPO levels in some...

Present data suggest that the primary site of thrombopoietin (TPO) mRNA is the liver. Previously, we reported that specific murine liver endothelial cells (LEC-1) located in the hepatic sinusoids support in vitro megakaryocytopoiesis from murine hematopoietic stem cells suggesting that these cells may be a source of TPO. We report here that TPO and its receptor, c-mpl, are coexpressed on cloned...