Chemorepulsion and thymocyte emigration.

Critical role of SP thymocyte motility in regulation of thymic output in neonatal Aire−/− mice

Autoimmune regulator (Aire) is essential in the perinatal period to prevent the multiorgan autoimmunity. Here we show that Aire-regulated single positive thymocyte trafficking in neonatal period is critical for thymic egress. Reduced thymic emigration was found in Aire-/- mice during neonatal period, leading to enhanced homeostatic expansion of peripheral T cells as early as 2 weeks of age. In ...

Thymocyte emigration is mediated by active movement away from stroma-derived factors.

T cells leave the thymus at a specific time during differentiation and do not return despite elaboration of known T cell chemoattractants by thymic stroma. We observed differentiation stage-restricted egress of thymocytes from an artificial thymus in which vascular structures or hemodynamics could not have been playing a role. Hypothesizing that active movement of cells away from a thymic produ...

A type 2 cytokine axis for thymus emigration

In the thymus, stromal microenvironments support a developmental program that generates mature T cells ready for thymic exit. The cellular and molecular specialization within thymic stromal cells that enables their regulation of specific stages of thymocyte development is poorly understood. Here, we show the thymic microenvironment expresses the type 2 IL-4R complex and is functionally responsi...

Ag-Specific Thymocytes In Vivo Mediate Positive Selection and Emigration of Peptide Variants of Viral CTL Epitopes

Control of human thymocyte migration by Neuropilin-1/Semaphorin-3A-mediated interactions.

It is largely established that molecules first discovered in the nervous system are also found in the immune system. Neuropilin-1 (NP-1) was initially identified to mediate semaphorin-induced chemorepulsion during brain development and is also involved in peripheral T cell/dendritic cell interactions. Herein, we studied NP-1 during T cell development in the human thymus. NP-1 is expressed in bo...