title: Lipoteichoic acid suppresses effector T cells induced by Staphylococcus aureus-pulsed dendritic cells.
abstract: Lipoteichoic acid (LTA), uniquely expressed on gram-positive bacteria, is recognized by Tolllike receptor 2 (TLR2) on not only antigen-presenting cells but also activated T cells. Therefore, it is reasonable to assume that LTA is acting on T cells. However, little is known about the effect of LTA on T-cell regulation. In the present study, we investigated the immunomodulatory effects of LTA on CD4⁺ T cells. Effector CD4⁺ T cells, induced after co-culture with S. aureuspulsed dendritic cells, produced high levels of interferon-γ, CD25, CD69, and TLRs 2 and 4. When effector CD4⁺ T cells were treated with LTA, the expressions of the membrane-bound form of transforming growth factor (TGF)-β and forkhead box P3 increased. Coincidently, the proliferation of effector CD4⁺ T cells was declined after LTA treatment. When TGF-β signaling was blocked by the TGF-β receptor 1 kinase inhibitor, LTA failed to suppress the proliferation of effector CD4⁺ T cells. Therefore, the present results suggest that LTA suppresses the activity of effector CD4⁺ T cells by enhancing TGF-β production.
authors.affiliation: Center for Food and Bioconvergence, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Young Min
authors.initials: YM
authors.lastname: Son
authors.forename: Ki-Duk
authors.initials: KD
authors.lastname: Song
authors.forename: Sung-Moo
authors.initials: SM
authors.lastname: Park
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Han
authors.forename: Cheol-Heui
authors.initials: CH
authors.lastname: Yun
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000276:immunology*; D013682:Teichoic Acids / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D013682:Teichoic Acids; D016212:Transforming Growth Factor beta; C009900:lipoteichoic acid