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Updated: Sep 27, 2026

Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
Competition for self ligands restrains homeostatic proliferation of naive CD4 T cells
Christina T Moses1, Kristen M Thorstenson, Stephen C Jameson
1Department of Medicine, Center for Immunology, University of Minnesota, Minneapolis, MN 55455, USA.
Abstract:
T cell antigen receptor (TCR) diversity is a critical feature of adaptive immunity. However, restriction of TCR diversity is a potential risk during immune reconstitution by homeostatic proliferation. What peripheral mechanisms are in place to maintain TCR diversity during recovery from lymphopenia? Here, we examine competition between several monoclonal CD4 T cell populations in RAG(-/-) and TCR Tg RAG(-/-) environments. The results suggest that specific self ligands constitute a critical limiting resource essential for homeostatic proliferation of naive CD4 T cells. In addition, T cells ignore large numbers of competitors as long as their TCR specificity is different and other non-MHC resources are not limiting. Therefore, the numbers of self ligands expressed in the periphery set the limits on TCR diversity.
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