A critical role for IL-10 in limiting inflammation during toxoplasmic encephalitis

J Neuroimmunol. 2005 Aug;165(1-2):63-74. doi: 10.1016/j.jneuroim.2005.04.018.


IL-10 plays a vital role in controlling the inflammatory response during acute Toxoplasma gondii infection, however the production of IL-10 during the chronic phase of toxoplasmosis has been associated with parasite persistence. To address this paradox, the production and effect of IL-10 in the brain during toxoplasmic encephalitis (TE) was investigated. Analysis of brain mononuclear cells (BMNC) from chronically infected mice revealed that infiltrating macrophages and CD4(+) T cells were the major sources of IL-10. Endogenous levels of IL-10 inhibited the production of IL-12, IFN-gamma, TNF-alpha, and IL-6 from both hematopoetic and non-hematopoetic cells in the brain, as well as anti-microbial activity of astrocytes. Furthermore, IL-10-/- mice that progressed to the chronic phase of infection had equivalent parasite burden to WT mice but developed a lethal inflammatory response within the brain characterized by increased numbers of CD4(+) T cells and macrophages, and elevated production of inflammatory cytokines. Finally, partial depletion of CD4(+) T cells decreased the severity of the inflammation in the brain and allowed IL-10-/- mice to survive infection. Together these results point to a vital role for IL-10 in the control of CD4(+) T cell mediated inflammation in the brain during TE.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Astrocytes / immunology
  • Astrocytes / metabolism
  • Astrocytes / pathology
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / parasitology
  • CD4-Positive T-Lymphocytes / pathology
  • Cell Differentiation / genetics
  • Cell Differentiation / immunology
  • Cells, Cultured
  • Chronic Disease
  • Down-Regulation / immunology
  • Encephalitis / immunology*
  • Encephalitis / parasitology
  • Encephalitis / pathology
  • Encephalitis / prevention & control*
  • Female
  • Inflammation Mediators / metabolism
  • Inflammation Mediators / physiology*
  • Interleukin-10 / biosynthesis
  • Interleukin-10 / deficiency
  • Interleukin-10 / genetics
  • Interleukin-10 / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred CBA
  • Mice, Knockout
  • Toxoplasma / growth & development
  • Toxoplasma / immunology
  • Toxoplasmosis, Cerebral / immunology*
  • Toxoplasmosis, Cerebral / pathology
  • Toxoplasmosis, Cerebral / prevention & control*


  • Inflammation Mediators
  • Interleukin-10