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: Transplantation tolerance: Lyt-1+2- helper T cells require a second proliferation signal to overcome Lyt- 1-2+ suppressor T cell activity.
    Author: Chen BP, Splitter GA.
    Journal: J Immunol; 1983 Jul; 131(1):57-63. PubMed ID: 6223083.
    Abstract:
    This study investigated why nude mouse T cell precursors that differentiated in an allogeneic thymus graft were rendered tolerant to alloantigens of the thymus genotype. Our results showed that Lyt- 1-,2+ suppressor T cells inhibited clonal expansion of helper T cells reactive to thymus-donor alloantigens as the mechanism of tolerance. This suppressor T cell activity could be modulated in vitro with either exogenous interleukin 2 (IL 2) or anti-Lyt-1 monoclonal antibody as an IL 2 inducer. Monoclonal antibody stimulation of IL 2 production by primed helper T cells was effective even in the presence of suppressor T cells. These results indicate: i) that alloantigen-specific helper T cells were not defective in their ability to recognize alloantigens of the thymus-donor genotype and to produce IL 2; ii) that Lyt-1-,2+ suppressor T cells prevented Lyt-1+,2- helper T cells specific for the thymus-donor alloantigens from producing IL 2; and iii) that signals delivered through binding of anti-Lyt-1 antibody modulated suppressor activity on alloantigen-primed helper T cells and permitted IL 2 production by these helper T cells. Accordingly, a delicate balance of helper and suppressor T cell activity was required for the maintenance of transplantation tolerance. Furthermore, these results argue against clonal deletion of Lyt-1+,2- helper T cells reactive to alloantigens of the thymic genotype as a mechanism of such transplantation tolerance.
    [Abstract] [Full Text] [Related] [New Search]