Anti-CD25 antibody-mediated depletion of effector T cell populations enhances susceptibility of mice to acute but not chronic Toxoplasma gondii infection

J Immunol. 2009 Apr 1;182(7):3985-94. doi: 10.4049/jimmunol.0803053.


Natural regulatory T cells (Tregs) constitutively express the IL-2R alpha-chain (CD25) on their surface. Consequently, administration of anti-CD25 Abs is a commonly used technique to deplete Treg populations in vivo. However, activated effector T cells may also transiently express CD25, and are thus also potential targets for anti-CD25 Abs. In this study using Toxoplasma gondii as a model proinflammatory infection, we have examined the capacity of anti-CD25 Abs to target effector T cell populations during an inflammatory episode, to determine to what extent that this action may modulate the outcome of disease. Anti-CD25 Ab-treated C57BL/6 mice displayed significantly reduced CD4(+) T cell IFN-gamma production during acute T. gondii infection and exhibited reduced weight loss and liver pathology during early acute infection; aspects of infection previously associated with effector CD4(+) T cell responses. In agreement, anti-CD25 Ab administration impaired parasite control and caused mice to succumb to infection during late acute/early chronic stages of infection with elevated tissue parasite burdens. In contrast, anti-CD25 Ab treatment of mice with established chronic infections did not markedly affect brain parasite burdens, suggesting that protective T cell populations do not express CD25 during chronic stages of T. gondii infection. In summary, we have demonstrated that anti-CD25 Abs may directly abrogate effector T cell responses during an inflammatory episode, highlighting important limitations of the use of anti-CD25 Ab administration to examine Treg function during inflammatory settings.

Publication types

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

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Flow Cytometry
  • Interleukin-2 Receptor alpha Subunit / immunology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Reverse Transcriptase Polymerase Chain Reaction
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocytes, Regulatory / immunology*
  • Toxoplasmosis / immunology*
  • Toxoplasmosis / pathology


  • Antibodies, Monoclonal
  • Interleukin-2 Receptor alpha Subunit