Differentiation of T cells is a complicated affair and there has been a dearth of markers that faithfully reflect thymocyte phenotype. A new strategy based on T-cell receptor gene sequencing has revealed a marker that can be used to monitor thymocyte differentiation with fidelity and without perturbation.

Differentiation-dependent thymocyte migration in the thymus may be important for T lymphopoiesis and might be regulated by thymic chemoattractants. We examined modulation of chemotactic responsiveness of thymocyte subsets during their early to late stages of development in response to 2 thymus-expressed chemokines, SDF-1 and CKbeta-11/MIP-3beta/ELC. SDF-1 shows chemotactic preference for immatu...

Developing thymocytes interact with thymic epithelial cells (TECs) through cell-cell interactions, TEC-derived secretory moieties and extracellular matrix (ECM)-mediated interactions. These physiological interactions are crucial for normal thymocyte differentiation, but can be disrupted in pathological situations. Indeed, there is severe thymic atrophy in animals acutely infected with Trypanoso...

The protein tyrosine kinase p56lck is critical for the generation of mature thymocytes in adult mice. However its requirement during the maturation of thymocytes from the fetal to the adult stage has not been clearly defined. We analyzed prenatal and postnatal thymocyte maturation in mice deficient for p56lck (lck[-/-]). Before birth, lck appears to play a crucial role in the expansion and prol...

Survival of CD4(+)CD8(+) double-positive (DP) thymocytes plays a critical role in shaping the peripheral T cell repertoire. However, the mechanisms responsible for the regulation of DP thymocyte lifespan remain poorly understood. In this work, we demonstrate that T cell factor (TCF)-1 regulates DP thymocyte survival by upregulating RORγt. Microarray analysis revealed that RORγt was significantl...

The thymus is a primary lymphoid organ, home of maturation and selection of thymocytes for generation of functional T-cells. Multiple factors are involved throughout the different stages of the maturation process to tightly regulate T-cell production. The metabolism of arachidonic acid by cyclooxygenases, lipoxygenases and specific isomerases generates eicosanoids, lipid mediators capable of tr...

The feline thymus is a target organ and site of viral replication during the acute stage of feline immunodeficiency virus (FIV) infection. This was demonstrated by histologic, immunohistologic, flow cytometric, and virologic tests. Thymic lesions developed after 28 days postinoculation (p.i.) and included thymitis, premature cortical involution, and medullary B-cell hyperplasia with germinal ce...