Published online
doi:10.1084/jem.20072390
The Journal of Experimental Medicine
The Rockefeller University Press, 0022-1007 $30.00
© Turner et al.
Avidity maturation of memory CD8 T cells is limited by self-antigen expression
Michael J. Turner,
Evan R. Jellison,
Elizabeth G. Lingenheld,
Lynn Puddington, and
Leo Lefrançois
Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
CORRESPONDENCE Leo Lefrançois: llefranc{at}neuron.uchc.edu
Immune tolerance to self-antigens is a complex process that utilizes multiple mechanisms working in concert to maintain homeostasis and prevent autoimmunity. We developed a system that revealed a population of self-specific CD8 T cells within the endogenous T cell repertoire. Immunization of ovalbumin (OVA)-expressing transgenic mice with recombinant viruses expressing OVA-peptide variants induced self-reactive T cells in vivo that matured into memory T cells able to respond to secondary infection. However, whereas the avidity of memory cells in normal mice increased dramatically with repeated immunizations, avidity maturation was limited for self-specific CD8 T cells. Despite decreased avidity, such memory cells afforded protection against infection, but did not induce overt autoimmunity. Further, up-regulation of self-antigen expression in dendritic cells using an inducible system promoted programmed death-1 expression, but not clonal expansion of preexisting memory cells. Thus, the self-reactive T cell repertoire is controlled by overlapping mechanisms influenced by antigen dose.
Abbreviations used: AIRE, autoimmune regulator; LM, Listeria monocytogenes; VSV, vesicular stomatitis virus; VV, vaccinia virus.
© 2008 Turner et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.jem.org/misc/terms.shtml). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).

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