TCR and IL-7 receptor signals can operate independently or synergize to promote lymphopenia-induced expansion of naive T cells.

Lymphopenia-Induced Expansion of Naive T Independently or Synergize to Promote TCR and IL-7 Receptor Signals Can Operate

IL-2 and IL-7 determine the homeostatic balance between the regulatory and conventional CD4+ T cell compartments during peripheral T cell reconstitution.

Work over the last decades has led to the identification of the factors that influence the survival and homeostasis of conventional T cells. IL-7 and TCR signaling promote the survival of naive CD4(+) and CD8(+) T cells in lymphoreplete mice and their proliferation in a lymphopenic environment, whereas survival and homeostatic proliferation of memory CD4(+) and CD8(+) T cells crucially depend o...

Severely impaired clonal deletion of CD4+ T cells in low-dose irradiated mice: role of T cell antigen receptor and IL-7 receptor signals.

Systemic administration of high doses of soluble Ag induces peripheral CD4+ T cell tolerance in unmanipulated hosts. To test whether tolerance is modified under conditions of transient lymphopenia, we tracked the response of 5C.C7 TCR-transgenic CD4+ T cells to i.v. moth cytochrome c peptide in mice that received low-dose gamma irradiation 10 days previously. This model was chosen because it do...

Zap70 is essential for long-term survival of naive CD8 T cells.

Survival of naive T cells requires engagement of TCR with self-peptide major histocompatibility Ags. The signaling pathways required to transmit this survival signal are poorly understood. In this study, we asked whether the tyrosine kinase Zap70 is required to transmit survival signals in naive CD8 T cells. In the absence of Zap70 expression, thymic development is completely blocked. Using a t...

Priming of T cells to Fas-mediated proliferative signals by interleukin-7.

T-cell depletion associated with HIV infection or cytoreductive therapies triggers potential T-cell regenerative mechanisms such as peripheral T-lymphocyte expansion to weak antigenic stimuli and the increased availability of interleukin-7 (IL-7), a cytokine with potent antiapoptotic and proliferative activities. Deleterious mechanisms also associated with lymphopenia, such as increased Fas exp...