Abrogation of CD40-CD154 signaling impedes the homeostasis of thymic resident regulatory T cells by altering the levels of IL-2, but does not affect regulatory T cell development.

ABSTRACT: Identification of costimulatory signals required for murine regulatory T (Treg) cell development relies on measuring the frequency of total thymic Treg cells. However, the thymus contains both resident and newly developed Treg cells; whether such signals target both populations is unknown. In this study, we show that CD40-CD154 blockade specifically targeted thymic resident Treg cells, but not, as was previously believed, newly developed Treg cells. Unlike CD28-CD80/CD86 signals, CD40-CD154 signals were not required for Treg cell precursor development. Instead we demonstrate that homeostatic proliferation of thymic resident Treg cells was dependent on CD40-CD154 signals maintaining IL-2 levels. Furthermore, in newborn mice, where all Treg cells are newly developed, blockade of CD40-CD154 s

SUBMITTER: Cuss SM 

PROVIDER: S-EPMC3442226 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature