OBJECTIVES To investigate the usefulness of 18-fluorine fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET-CT) in the pretreatment evaluation of thymic epithelial neoplasms (TENs). We previously demonstrated that the ratio between standardized uptake value of the tumour and aortic arch (SUV T/M) correlates with World Health Organization (WHO) classification. We...

Congenital cysts are typically unilocular and thin-walled to the point of translucency; careful histopathologic examination shows no evidence of inflammation. In contrast, acquired thymic cysts are usually multilocular, hence the commonly used term “multilocular thymic cyst (MTC).” These cysts have thick, fibrous walls, and histopathologic examination typically reveals significant inflammation ...

In this issue of Blood, Dertschnig and colleagues1 demonstrate in mice that acute graft-versus-host disease (GHVD) results in a marked reduction of autoimmune receptor–expressing medullary thymic epithelial cells (Aire1 mTEC) and a decrease in the diversity of Aire-dependent tissue-restricted peripheral selfantigens (TRAs) required for effective negative thymic selection. Both of these abnormal...

To characterize thymic epithelial cells of SCID (severe combined immunodeficiency) mice in comparison with those of Balb C mice, we did an immunohistochemical study using cortical and medullary epithelial cell specific monoclonal antibodies (MoAbs), Th-3 and Th-4, as well as gel electrophoresis and immunoblotting. The thymi of SCID mice were composed of epithelial cells and a few lymphocytes. M...

The thymic medulla is critical for the enforcement of central tolerance. In addition to deletion of auto-reactive T-cells, the thymic medulla supports the maturation of heterogeneous natural αβT-cells linked to tolerance mechanisms. Natural IL-17-secreting CD4(+)αβT-cells (nTh17) represent recently described natural αβT-cells that mature and undergo functional priming intrathymically. Despite a...

Transgenic mice were generated expressing NK1.1, an NK cell-associated receptor, under control of the human CD2 promoter. Unexpectedly, one of the founder lines, Tg66, showed a marked defect in thymic development characterized by disorganized architecture and small size. Mapping of the transgene insertion by fluorescence in situ hybridization revealed integration in chromosome 2, band G. Alread...

Pluripotent stem cells have the capacity to generate all cell lineages, and substantial progress has been made in realizing this potential. One fascinating but as yet unrealized possibility is the differentiation of pluripotent stem cells into thymic epithelial cells. The thymus is a primary lymphoid organ essential for naïve T-cell generation. T cells play an important role in adaptive immunit...

T-cell development is under the tight control of thymic microenvironments. Conversely, the integrity of thymic microenvironments depends on the physical presence of developing thymocytes, a phenomenon designated as 'thymic crosstalk'. We now show, using three types of immunodeficient mice, i.e. CD3(epsilon) transgenic mice, RAG(null) mice and RAG(null)-bone-marrow-transplanted CD3(epsilon) tran...

Bone marrow progenitors migrate to the thymus, where they proliferate and differentiate into immunologically competent T cells. In this report we show that mice transgenic for SV40 T and t antigens under the control of the L-pyruvate kinase promoter develop, in a first step, thymic hyperplasia of both thymocytes and epithelial cells. Morphological studies (histology, immunohistolabeling and ele...

Interleukin-3 (IL-3) is a hematopoietic growth factor suggested to be produced by activated T lymphocytes. Meanwhile, supernatants from human thymic stroma could promote the proliferation of myeloid stem cells. Thus, we investigated whether IL-3 accounts for this activity. Therefore, human thymic epithelial cells (TEC), fibroblasts, and adherent cells were isolated, and their culture supernatan...