Human thymopoiesis and naïve T cell maintenance throughout life (LYM7P.724)
| Autor: | Joseph Thome, Melissa Ventevogel, Yoshiaki Ohmura, Tomoaki Kato, Gregory Sempowski, Donna Farber |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 192:193.12-193.12 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | The extent to which thymopoieis is diminished over the human lifespan and how this affects the naïve T cell repertoire in peripheral tissue sites is not well characterized. In collaboration with the New York Organ Donor Network, we have attained novel access to thymus and secondary tissues from deceased organ donors. From this, it is possible to correlate naïve T cell development to distribution in tissue sites from the same individual effectively identifying when functional thymopoiesis is halted and how this affects the naïve T cell pool over time. We have found marked cessation of functional thymopoiesis in donors over 40 years of age but strikingly naïve T cells are maintained in lymph node tissue sites for decades undergoing low levels of proliferation and turnover comprising over 20% of total T cells in donors aged 40-73. When profiling double negative (DN) stage thymocytes using CD25 and CD44, DN1 thymocytes accumulate in donors with negligible thymic output indicating a lack of progenitor cells to progress to maturation while identified recent thymic emigrants (RTE) exhibit differential distribution and regulation in tissues during periods of active thympopoiesis but are evenly distributed in the spleen and lymph nodes when the export of new naïve T cells is halted. Together this indicates that naïve T cell populations are uniquely maintained as a function of thymic activity in order to preserve the ability to respond to new pathogen throughout the human lifetime. |
| Databáze: | OpenAIRE |
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