You are currently viewing the abstract.
View Full TextLog in to view the full text
AAAS login provides access to Science for AAAS members, and access to other journals in the Science family to users who have purchased individual subscriptions.
Register for free to read this article
As a service to the community, this article is available for free. Existing users log in.
More options
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
T cell life doesn’t end at 40
Naïve T cells develop in the thymus. Although thymic function declines with age, T cells are persistent throughout the human life span. Thome et al. examined human lymphoid tissues from donors ranging from 2 months to 73 years in age. They found that, although the number of double-positive thymocytes and recent thymic emigrants dropped in individuals >40 years of age, naïve T cells were functionally maintained in the lymph nodes. There was minimal overlap in clonotype between the lymph tissues, suggesting that lymph nodes may maintain a diverse set of T cell specificities. These data suggest that location really does matter—tissue compartmentalization and homeostasis are critical for maintaining naïve T cells throughout the human life span.
Abstract
Naïve T cells develop in the thymus and coordinate immune responses to new antigens; however, mechanisms for their long-term persistence over the human life span remain undefined. We investigated human naïve T cell development and maintenance in primary and secondary lymphoid tissues obtained from individual organ donors aged 2 months to 73 years. In the thymus, the frequency of double-positive thymocytes declined sharply in donors >40 years of age, coincident with reduced recent thymic emigrants in lymphoid tissues, whereas naïve T cells were functionally maintained predominantly in lymph nodes (LNs). Analysis of T cell receptor clonal distribution by CDR3 sequencing of naïve CD4+ and CD8+ T cells in spleen and LNs reveals site-specific clonal expansions of naïve T cells from individuals >40 years of age, with minimal clonal overlap between lymphoid tissues. We also identified biased naïve T cell clonal distribution within specific LNs on the basis of VJ usage. Together, these results suggest prolonged maintenance of naïve T cells through in situ homeostasis and retention in lymphoid tissue.
- Copyright © 2016, American Association for the Advancement of Science