These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Costimulation by interleukin-1 of multiple activation responses in a developmentally restricted subset of immature thymocytes.
    Author: Rothenberg EV, Diamond RA.
    Journal: Eur J Immunol; 1994 Jan; 24(1):24-33. PubMed ID: 8020563.
    Abstract:
    An intriguing feature of thymocyte differentiation is that the competence to express both interleukin-(IL)2 and CD25 is acquired even prior to T cell receptor (TcR) expression. When T cell receptor-independent stimuli are used, immature cells can express IL-2 at levels comparable to mature cells, but unlike the mature cells, immature cells require IL-1 as a costimulus. Here we present evidence that IL-1 affects a variety of responses by members of the CD25+ subset of immature thymocytes. Cells in this population are IL-1 dependent not only for induction of IL-2 expression, but also for high-level maintenance of CD25 expression. CD25 expression is amplified by IL-1 through a mechanism highly sensitive to changes in Ca2+ ionophore concentration. The effects of IL-1 on CD25 maintenance are not mediated by IL-2, because of the divergent effects of cAMP on IL-2 and CD25 expression. IL-1 costimulation also increases RNA accumulation in the cell cycle, and this effect too seems to be separable from the effects on IL-2 and CD25 expression. All these effects of IL-1 are developmentally stage-specific, manifest in the CD25+ subset of immature thymocytes but not in later-stage thymocytes or splenic T cells. Multiparameter cell sorting experiments that dissect the transitional stages between immature and TcR+ thymocytes imply that all immature cells pass through an IL-1 responsive state. Responsiveness to IL-1 costimulation is then lost by these cells, apparently irreversibly, at a stage just prior to detectable cell-surface TcR expression. These results indicate that IL-1 responsiveness is a defining characteristic of the activation physiology of cells in a particularly important developmental stage.
    [Abstract] [Full Text] [Related] [New Search]