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Updated: Aug 15, 2026

Generation of Human Alloantigen-specific T Cells from Peripheral Blood
Published on: November 21, 2014
Fratricide: a mechanism for T memory-cell homeostasis
Robin E Callard1, Jaroslav Stark, Andrew J Yates
1Immunobiology Unit, Institute of Child Health, University College London, 30 Guilford Street, WC1N 1EH, London, UK. rcallard@ich.ucl.ac.uk <rcallard@ich.ucl.ac.uk>
Abstract:
Immunological memory depends on a self-renewing pool of antigen-specific T memory (Tm) cells but the homeostatic mechanisms that maintain the size and diversity of the pool are largely unknown. Competition for space or growth factors has been suggested as a mechanism but how these factors themselves are regulated is unclear. We suggest that Tm-cell fratricide by Fas-mediated apoptosis results in a density-dependent death rate that controls the size of the pool without requiring competition for resources or an external quorum-sensing mechanism. A mathematical model based on this concept predicts the known behaviour of the Tm pool, including observed differences in heterogeneity of the CD4 and CD8 compartments and might provide a paradigm for homeostasis of other haematopoietic-cell populations.
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