Loss of CD4+ T cell IL-6R expression during inflammation underlines a role for IL-6 trans signaling in the local maintenance of Th17 cells

J Immunol. 2010 Feb 15;184(4):2130-9. doi: 10.4049/jimmunol.0901528. Epub 2010 Jan 18.

Abstract

IL-6 responses are classically orchestrated via a membrane-bound IL-6R (CD126) alpha subunit (classical IL-6R signaling) or through a soluble form of this cognate receptor (IL-6 trans signaling). Appraisal of IL-6R expression on human and mouse T cells emphasized that IL-6R expression is closely linked with that of CCR7 and CD62L. In this regard, infiltrating effector T cells from clinical and experimental peritonitis episodes lose IL-6R expression, and anti-CD3/CD28 Ab costimulation of peripheral T cells in vitro leads to a downregulation in IL-6R expression. Consequently, IL-6 signaling through membrane-bound IL-6R seems to be limited to naive or central memory T cell populations. Loss of IL-6R expression by activated T cells further suggests that these effector cells might still retain IL-6 responsiveness via IL-6 trans signaling. Using IL-6R-deficient mice and recombinant tools that modulate the capacity of IL-6 to signal via its soluble receptor, we report that local control of IL-6 trans signaling regulates the effector characteristics of the T cell infiltrate and promotes the maintenance of IL-17A-secreting CD4(+) T cells. Therefore, we concluded that classical IL-6R signaling in naive or central memory CD4(+) T cells is required to steer their effector characteristics, whereas local regulation of soluble IL-6R activity might serve to maintain the cytokine profile of the Th cell infiltrate. Therefore, the activation status of a T cell population is linked with an alteration in IL-6 responsiveness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / pathology*
  • Cell Movement / genetics
  • Cell Movement / immunology
  • Cells, Cultured
  • Cytokines / biosynthesis
  • Cytokines / genetics
  • Down-Regulation / genetics
  • Down-Regulation / immunology
  • Female
  • Humans
  • Immunophenotyping
  • Inflammation Mediators / antagonists & inhibitors
  • Inflammation Mediators / physiology*
  • Interleukin-17 / biosynthesis
  • Interleukin-17 / metabolism*
  • Interleukin-6 / deficiency
  • Interleukin-6 / genetics
  • Interleukin-6 / physiology*
  • Lymphocyte Activation / genetics
  • Lymphocyte Activation / immunology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Peritonitis / immunology*
  • Peritonitis / microbiology
  • Peritonitis / pathology
  • Receptors, Interleukin-6* / deficiency
  • Receptors, Interleukin-6* / genetics
  • Receptors, Interleukin-6* / physiology
  • Signal Transduction / genetics
  • Signal Transduction / immunology*
  • Staphylococcal Infections / immunology
  • Staphylococcal Infections / pathology
  • T-Lymphocytes, Helper-Inducer / immunology*
  • T-Lymphocytes, Helper-Inducer / metabolism
  • T-Lymphocytes, Helper-Inducer / pathology

Substances

  • Cytokines
  • Inflammation Mediators
  • Interleukin-17
  • Interleukin-6
  • Receptors, Interleukin-6