title: CpG DNA inhibits CD4+CD25+ Treg suppression through direct MyD88-dependent costimulation of effector CD4+ T cells.
abstract: Toll-like receptor (TLR) ligands are notable for their ability to induce APC maturation, which in turn facilitates optimal T cell mediated immune responses. Toll-like receptor ligands, such as CpG DNA, can also modulate immune responses by blocking the suppressive effects of CD4+CD25+ regulatory T cells (Tregs). Recently, we have demonstrated that CpG DNA, in addition to its actions on APCs and Tregs, can provide direct costimulatory signals to CD4+CD25- T cells. Here we show that this costimulatory effect is sufficient to abrogate suppression by Tregs. These data indicate a previously undefined role for TLR ligands in directly modulating CD4+ T cell responses.
authors.affiliation: Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: LaRosa
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Gelman
authors.forename: Adeeb H
authors.initials: AH
authors.lastname: Rahman
authors.forename: Jidong
authors.initials: J
authors.lastname: Zhang
authors.forename: Laurence A
authors.initials: LA
authors.lastname: Turka
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Walsh
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D018920:Coculture Techniques; D051858:Forkhead Transcription Factors / Q000378:metabolism; D007108:Immune Tolerance / Q000187:drug effects / Q000276:immunology; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D053594:Myeloid Differentiation Factor 88 / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; C408982:CPG-oligonucleotide; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D007376:Interleukin-2; D053645:Interleukin-2 Receptor alpha Subunit; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D009838:Oligodeoxyribonucleotides