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

Search MEDLINE/PubMed


  • Title: Regulation of cytokine production in the human thymus: epidermal growth factor and transforming growth factor alpha regulate mRNA levels of interleukin 1 alpha (IL-1 alpha), IL-1 beta, and IL-6 in human thymic epithelial cells at a post-transcriptional level.
    Author: Le PT, Lazorick S, Whichard LP, Haynes BF, Singer KH.
    Journal: J Exp Med; 1991 Nov 01; 174(5):1147-57. PubMed ID: 1940795.
    Abstract:
    Human thymic epithelial (TE) cells produce interleukin 1 alpha (IL-1 alpha), IL-1 beta, and IL-6, cytokines that are important for thymocyte proliferation. The mRNAs for these cytokines are short-lived and are inducible by multiple stimuli. Thus, the steady-state levels for IL-1 and IL-6 mRNAs are critical in establishing the final cytokine protein levels. In this study we have evaluated the effect of epidermal growth factor (EGF), a growth factor for TE cells, and its homologue transforming growth factor alpha (TGF-alpha), on primary cultures of normal human TE cells for the levels of IL-1 alpha, IL-1 beta, IL-6, and TGF-alpha mRNA. We showed that TE cells expressed EGF receptors (EGF-R) in vitro and in vivo, and that treatment of TE cells with EGF or TGF-alpha increased IL-1 and IL-6 biological activity and mRNA levels for IL-1 alpha, IL-1 beta, and IL-6. Neither EGF nor TGF-alpha increased transcription rates of IL-1 alpha, IL-1 beta, and IL-6 genes, but rather both EGF and TGF-alpha increased cytokine mRNA stability. By indirect immunofluorescence assay, TGF-alpha was localized in medullary TE cells and thymic Hassall's bodies while EGF-R was localized to TE cells throughout the thymus. Thus, TGF-alpha and EGF are critical regulatory molecules for production of TE cell-derived cytokines within the thymus and may function as key modulators of human T cell development in vivo.
    [Abstract] [Full Text] [Related] [New Search]