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: Impaired post-transcriptional expression of interleukin-2 receptor in pokeweed mitogen-activated T cells.
    Author: de la Calle-Martín O, Alberola-Ila J, Engel P, Inglés J, Fabregat V, Barceló JJ, Lozano F, Gallart T.
    Journal: Eur J Immunol; 1992 Apr; 22(4):897-902. PubMed ID: 1551406.
    Abstract:
    The expression and role of interleukin-2/interleukin-2 receptor (IL-2/IL-2R) system in the pokeweed mitogen (PWM)-induced T cell mitogenesis was studied. In the absence of monocytes (Mo), both soluble and Sepharose-bound PWM fail to induce T cell mitogenesis even when exogenous IL-2 or IL-1 or IL-1 + IL-2 or IL-4 are also present. In the presence of Mo, PWM stimulation of T lymphocytes (highly depleted of B lymphocytes) induces as much IL-2 mRNA as phytohemagglutinin (PHA), but results in higher and persistent IL-2 levels in culture supernatants despite the concomitant T cell mitogenesis, suggesting that PWM-activated T cells do not utilize the IL-2 they produce. Confirming this notion, Mo-dependent PWM-preactivated T cells, as compared to PHA-preactivated ones: (a) failed to consume exogenous IL-2 and their mitogenic response did not increase upon exposure to exogenous IL-2; (b) exhibited very low numbers of high-affinity IL-2R; and (c) showed lower expression of IL-2R p55 and undetectable expression of IL-2R p75 on their surface. Moreover, the PWM-induced T cell mitogenesis was not inhibited by anti-IL-2 or CD25 antibodies and only partially (50%-60%) inhibited by cyclosporin A, while these treatments abrogated the PHA-induced one. PWM-activated T cells, as compared to the PHA-activated ones, exhibited as high (p55) or even higher (p75) mRNA expression of both IL-2R p55 and p75 subunits. The possibility that PWM interferes with IL-2R subunits once expressed on the T cell surface was excluded. Thus, intracellular PWM-related events are likely to impair IL-2R expression post-transcriptionally. Possible explanations for this effect and its relation with the capacity of PWM to induce T cell-dependent B cell differentiation are discussed.
    [Abstract] [Full Text] [Related] [New Search]