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: Heterogeneous mechanisms of human cytotoxic T lymphocyte generation. II. Differential effects of IL-6 on the helper cell-independent generation of CTL from CD8+ precursor subpopulations.
    Author: Bass HZ, Yamashita N, Clement LT.
    Journal: J Immunol; 1993 Sep 15; 151(6):2895-903. PubMed ID: 8376760.
    Abstract:
    The subpopulations of CD8+ T cells defined by CD45RA Ag expression have been hypothesized to represent cells varying in their relative maturation along a common, activation-dependent differentiation pathway. Although both the CD8+CD45RA+ and CD8+CD45RA- subsets contain precursor cells that can develop into alloreactive CTL, these subsets differ in their ability to produce and use IL-2, a cytokine that is essential for T helper cell-independent CTL generation. In these studies, we have characterized the ability of these CD8+ subsets to undergo CTL differentiation in response to IL-6, another cytokine reported to be important or even essential for CTL generation. Purified CD8+CD45RA+ or CD8+CD45RA- cells were stimulated with allogeneic B cell lines, either alone or in the presence of exogenous cytokines. Alloactivated CD8+CD45RA- cells failed to differentiate into cytotoxic cells in the presence of IL-6 alone. In contrast, IL-6 stimulated the differentiation of antigen-specific CTL from alloactivated CD8+CD45RA+ precursors. The mechanism underlying this helper cell-independent process appeared to require IL-2, because IL-6-mediated CTL generation was abrogated by anti-CD25 or anti-IL-2 antibodies. Although CD8+CD45RA- cells did not respond to IL-6 alone, these cells were able to respond to IL-6 in a synergistic fashion in the presence of suboptimal concentrations of exogenous IL-2. These studies demonstrate that the CD8+ precursor subsets defined by CD45RA expression differ in their ability to undergo IL-6-mediated helper cell-independent CTL generation. Our data further suggest that this functional dissimilarity results from putative maturation-linked differences in the ability of these CD8+ precursor cells to produce IL-2.
    [Abstract] [Full Text] [Related] [New Search]