title: Reduction of Foxp3+ cells by depletion with the PC61 mAb induces mortality in resistant BALB/c mice infected with Toxoplasma gondii.
abstract: Regulatory T cells (Tregs) are CD4(+)Foxp3(+) cells that modulate autoimmune responses. Tregs have been shown to be also involved during the immune response against infectious agents. The aim of this work is to study the role of Tregs during the infection with the intracellular protozoan Toxoplasma gondii. Resistant BALB/c mice were injected with 200 microg of anti-CD25 mAb (clone PC61) and 2 days later they were infected with 20 cysts of the ME49 strain of T. gondii. We observed that depleted mice showed 50-60% mortality during the acute infection. When FACS analysis was carried out, we observed that although injection of PC61 mAb eliminated 50% of Tregs, infected-depleted mice showed a similar percentage of CD25(+)Foxp3(-) (activated T cells, Tact) to those observed in infected nondepleted animals, demonstrating that in our depletion/infection system, injection of PC61 mAb did not hamper T cell activation while percentage of Tregs was reduced by 75% 10 days post infection. We concluded that Tregs are essential during protection in the acute phase of T. gondii infection.
authors.affiliation: Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, C.U., CP 04510, Mexico City, Mexico.
authors.forename: Eda Patricia
authors.initials: EP
authors.lastname: Tenorio
authors.forename: Jonadab Efraín
authors.initials: JE
authors.lastname: Olguín
authors.forename: Jacquelina
authors.initials: J
authors.lastname: Fernández
authors.forename: Pablo
authors.initials: P
authors.lastname: Vieyra
authors.forename: Rafael
authors.initials: R
authors.lastname: Saavedra
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D007113:Immunity, Innate; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D016019:Survival Analysis; D015996:Survival Rate; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D014122:Toxoplasma / Q000187:drug effects / Q000502:physiology*; D014123:Toxoplasmosis / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse