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Examination of Thymic Positive and Negative Selection by Flow Cytometry
14:29

Examination of Thymic Positive and Negative Selection by Flow Cytometry

Published on: October 8, 2012

The peptide ligands mediating positive selection in the thymus control T cell survival and homeostatic proliferation

B Ernst1, D S Lee, J M Chang

  • 1Department of Immunology, IMM26, The Scripps Research Institute, La Jolla, California 92037, USA.

Immunity
|September 15, 1999
PubMed

Positive selection to self-MHC/peptide complexes has long been viewed as a device for skewing the T cell repertoire toward recognition of foreign peptides presented by self-MHC molecules. Here, we provide evidence for an alternative possibility, namely, that the self-peptides controlling positive selection in the thymus serve to maintain the longevity of mature T cells in the periphery. Surprisingly, when total T cell numbers are reduced, these self-ligands become overtly stimulatory and cause naive T cells to proliferate and undergo homeostatic expansion.

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