title: Anti-CD25 antibody-mediated depletion of effector T cell populations enhances susceptibility of mice to acute but not chronic Toxoplasma gondii infection.
abstract: 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.
authors.affiliation: Trudeau Institute, Saranac Lake, NY 12983, USA. kevin.couper@lshtm.ac.uk
authors.forename: Kevin N
authors.initials: KN
authors.lastname: Couper
authors.forename: Paula A
authors.initials: PA
authors.lastname: Lanthier
authors.forename: Georgia
authors.initials: G
authors.lastname: Perona-Wright
authors.forename: Lawrence W
authors.initials: LW
authors.lastname: Kummer
authors.forename: Wangxue
authors.initials: W
authors.lastname: Chen
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Smiley
authors.forename: Markus
authors.initials: M
authors.lastname: Mohrs
authors.forename: Lawrence L
authors.initials: LL
authors.lastname: Johnson
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014123:Toxoplasmosis / Q000276:immunology* / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D053645:Interleukin-2 Receptor alpha Subunit