Cytokine production of CD8+ immune T cells but not of CD4+ T cells from Toxoplasma gondii-infected mice is polarized to a type 1 response following stimulation with tachyzoite-infected macrophages.
To examine whether cytokine production of CD4(+)immune T cells and CD8(+)immune T cells in Toxoplasma gondii-infected mice differ in their responses to infected cells and to soluble antigens of the parasite, we compared the production of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-4, and IL-10 by the immune T cell populations following in vitro stimulation with tachyzoite-infected macrophages and tachyzoite lysate antigens (TLA). Both CD4(+)and CD8(+)immune T cells produced large amounts of IFN-gamma in response to either infected macrophages or TLA, but the CD4(+)T cells produced greater amounts of the cytokine than did the CD8(+)T cells with both stimulations. Both T cell populations also produced IL-2 after stimulation with infected macrophages, whereas only CD4(+)T cells did when stimulated with TLA. CD4(+)immune T cells also produced large amounts of IL-4 and IL-10 after stimulation with infected macrophages, but CD8(+)T cells did not. These results indicate that CD4(+)immune T cells produce IFN-gamma, IL-2, IL-4, and IL-10 in response to infected macrophages, whereas CD8(+)immune T cells produce predominantly IFN-gamma and IL-2. Since IL-4 and IL-10 could suppress IFN-gamma-mediated protective mechanisms against the parasite, the production of these cytokines by CD4(+)immune T cells in response to infected cells could negatively affect their protective activity in vivo.
Miller
Renee
R
Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Wen
Xiangshu
X
Dunford
Bradley
B
Wang
Xisheng
X
Suzuki
Yasuhiro
Y
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000469:parasitology; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000276:immunology*; D005260:Female; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D018417:Th1 Cells / Q000276:immunology* / Q000469:parasitology; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000276:immunology*
D016207:Cytokines