We have previously shown that enhanced antitumor cytotoxicity is generated when thymocytes from melphalan (L-phenylalanine mustard; L-PAM)-treated MOPC-315 tumor bearers, but not thymocytes from normal mice, are added to the immunization culture of syngeneic normal spleen cells and MOPC-315 tumor cells (Bartik et al.. Cancer Res., 47: 4848-4855,1987). Here we show that normal spleen cells produ...

Previously, we described a mAb (1-23) reacting with a novel cell surface antigen expressed on thymocytes at late CD4-CD8- [(double negative (DN)] to early CD4+CD8+ [(double positive (DP)] differentiation stage. Since the expression of this molecule was restricted to immature thymocytes, we designated it as immature thymocyte antigen-1 (IMT-1). In this study, we have investigated the relevance o...

Abstract The thymus is composed of thymocytes and stromal cells including thymic epithelial mesenchymal cells. Thymic are originated from Neural Crest (NC) the mesoderm. Although it known that NC-derived (NCd) contribute to organogenesis development, their specific role in T cell regeneration unclear. To evaluate regenerative ability NCd thymus, we used lethally irradiated mice examine effect i...

Developing thymocytes are screened for self-reactivity before exiting the thymus, but how thymocytes scan the medulla for self-antigens is unclear. Using two-photon microscopy, we observed that medullary thymocytes migrated rapidly and made frequent, transient contacts with dendritic cells. In the presence of a negative selecting ligand, thymocytes slowed, became confined to areas of approximat...

The migration of developing T cells (thymocytes) between distinct thymic microenvironments is crucial for their development. Ex vivo studies of thymus tissue explants suggest two distinct migratory behaviors of thymocytes in the thymus. In the cortex, thymocytes exhibit a stochastic migration, whereas medullary thymocytes show confined migratory behavior. Thus far, it has been difficult to foll...

We have previously shown that enhanced antitumor cytotoxicity is generated when thymocytes from melphalan (L-phenylalanine mustard; L-PAM)-treated MOPC-315 tumor bearers, but not thymocytes from normal mice, are added to the immunization culture of syngeneic normal spleen cells and MOPC-315 tumor cells (Bartik et al., Cancer Res., 47: 4848-4855, 1987). Here we show that normal spleen cells prod...

The cellular and subcellular distribution of terminal deoxynucleotidyl transferase (DNA nucleotidylexotransferase; nucleosidetriphosphate:DNA deoxynucleotidylexotransferase, EC 2.7.7.31) in thymocytes and peripheral lymphocytes from rat, mouse, and calf was studied by immunofluorescence using rabbit antiserum to homogeneous transferase from calf. Terminal transferase was readily detected in app...

Death by neglect requires that CD4+8+ double-positive (DP) thymocytes avoid cytokine-mediated survival signals, which is presumably why DP thymocytes normally extinguish IL-7R gene expression. We report that DP thymocytes before positive selection (preselection DP thymocytes) fail to transduce IL-7 signals even when they express high levels of transgenic IL-7R on their surface, because IL-7R si...

CTLA-4, a homologue of CD28, is a negative regulator of T cell activation in the periphery and is transiently expressed on the cell surface after T cell activation. However, the role of CTLA-4 in T cell activation in the thymus is not clear. This investigation was initiated to determine the role of CTLA-4 in the activation of CD4(+)CD8(+) double-positive (DP) and CD4(+)CD8(-) and CD4(-)CD8(+) s...

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...