Preferential escape of subdominant CD8+ T cells during negative selection results in an altered antiviral T cell hierarchy

MK Slifka, JN Blattman, DJD Sourdive, F Liu… - The Journal of …, 2003 - journals.aai.org
MK Slifka, JN Blattman, DJD Sourdive, F Liu, DL Huffman, T Wolfe, A Hughes, M Oldstone…
The Journal of Immunology, 2003journals.aai.org
Negative selection is designed to purge the immune system of high-avidity, self-reactive T
cells and thereby protect the host from overt autoimmunity. In this in vivo viral infection
model, we show that there is a previously unappreciated dichotomy involved in negative
selection in which high-avidity CD8+ T cells specific for a dominant epitope are eliminated,
whereas T cells specific for a subdominant epitope on the same protein preferentially
escape deletion. Although this resulted in significant skewing of immunodominance and a …
Abstract
Negative selection is designed to purge the immune system of high-avidity, self-reactive T cells and thereby protect the host from overt autoimmunity. In this in vivo viral infection model, we show that there is a previously unappreciated dichotomy involved in negative selection in which high-avidity CD8+ T cells specific for a dominant epitope are eliminated, whereas T cells specific for a subdominant epitope on the same protein preferentially escape deletion. Although this resulted in significant skewing of immunodominance and a substantial depletion of the most promiscuous T cells, thymic and/or peripheral deletion of high-avidity CD8+ T cells was not accompanied by any major change in the TCR Vβ gene family usage or an absolute deletion of a single preferred complementarity-determining region 3 length polymorphism. This suggests that negative selection allows high-avidity CD8+ T cells specific for subdominant or cryptic epitopes to persist while effectively deleting high-avidity T cells specific for dominant epitopes. By allowing the escape of subdominant T cells, this process still preserves a relatively broad peripheral TCR repertoire that can actively participate in antiviral and/or autoreactive immune responses.
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