Toll Pathway-Dependent Blockade of CD4+CD25+ T Cell-Mediated Suppression by Dendritic Cells

C Pasare, R Medzhitov - Science, 2003 - science.org
Science, 2003science.org
Toll-like receptors (TLRs) control activation of adaptive immune responses by antigen-
presenting cells (APCs). However, initiation of adaptive immune responses is also controlled
by regulatory T cells (TR cells), which act to prevent activation of autoreactive T cells. Here
we describe a second mechanism of immune induction by TLRs, which is independent of
effects on costimulation. Microbial induction of the Toll pathway blocked the suppressive
effect of CD4+ CD25+ TR cells, allowing activation of pathogen-specific adaptive immune …
Toll-like receptors (TLRs) control activation of adaptive immune responses by antigen-presenting cells (APCs). However, initiation of adaptive immune responses is also controlled by regulatory T cells (TR cells), which act to prevent activation of autoreactive T cells. Here we describe a second mechanism of immune induction by TLRs, which is independent of effects on costimulation. Microbial induction of the Toll pathway blocked the suppressive effect of CD4+CD25+ TR cells, allowing activation of pathogen-specific adaptive immune responses. This block of suppressor activity was dependent in part on interleukin-6, which was induced by TLRs upon recognition of microbial products.
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