Reinterpreting recent thymic emigrant function: defective or adaptive?

Identification of a human recent thymic emigrant phenotype.

The ability to measure human thymic output would be an invaluable tool for the study of the development of the naive T cell repertoire, as well as naive T cell regeneration after intensive cytotoxic chemotherapy or effective antiretroviral therapy of progressive HIV infection. We and others have demonstrated previously that quantification of T cell receptor rearrangement excision circles (TREC)...

Levels of recent thymic emigrant cells decrease in children undergoing partial thymectomy during cardiac surgery.

The human thymus is required for establishment of a T-cell pool in fetal life, but postnatal thymectomy is not known to cause immunodeficiency. T-cell emigration from thymus (thymic recent emigrants [TRECs]) is a continuous thymic-dependent process. We studied TREC levels pre- and post-partial thymectomy in children undergoing cardiac surgery. TRECs were quantitated by real-time PCR in peripher...

Exogenous IL-7 increases recent thymic emigrants in peripheral lymphoid tissue without enhanced thymic function.

Interleukin 7 (IL-7) is critical in maintaining thymic-dependent and thymic-independent pathways of T-cell homeostasis. T-cell receptor (TCR) rearrangement excision circles (TRECs) have been used as markers for recent thymic emigrants (RTEs) in assessing human thymic function. To study the thymic and peripheral effects of IL-7 on RTEs, we measured TREC content and peripheral naive T-cell subset...

Sparse production but preferential incorporation of recently produced naive T cells in the human peripheral pool.

In mice, recent thymic emigrants (RTEs) make up a large part of the naïve T cell pool and have been suggested to be a distinct short-lived pool. In humans, however, the life span and number of RTEs are unknown. Although (2)H(2)O labeling in young mice showed high thymic-dependent daily naïve T cell production, long term up- and down-labeling with (2)H(2)O in human adults revealed a low daily pr...

Emigrant or Sojourner? Migration Intensity and Its Determinants