title: CpG and non-CpG oligodeoxynucleotides directly costimulate mouse and human CD4+ T cells through a TLR9- and MyD88-independent mechanism.
abstract: TLR ligands are known to activate APCs, but direct T cell responsiveness to TLR ligands is controversial. Because of their clinical relevance, we performed in-depth studies of the effects of the TLR9-associated ligands, oligodeoxynucleotides (ODNs), on highly purified T lymphocytes. Both CpG and non-CpG ODNs directly costimulate mouse and human CD4(+) T cells, resulting in activation marker upregulation, cytokine secretion, elevated TCR phosphorylation, and proliferation. Surprisingly, ODN costimulation occurred independently of TLR9 and MyD88, as well as ICOS, CD28, and TRIF. TLR9-antagonist ODNs likewise promoted T cell activation, which has important implications for the study of these "inhibitory" ODNs in inflammatory diseases. Cytokine profiling revealed that ODNs promote polarization of distinct Th subsets, and that ODNs differentially affect human naive and memory T cells. Our studies reveal a striking and unexpected ability of ODNs to directly activate and polarize T cells, presenting an opportunity to enhance the paradigm for selection of therapeutic ODNs in humans.
authors.affiliation: Division of Immunology and Rheumatology, Department of Medicine, Stanford University, Stanford, CA 94305, USA. alandrig@post.harvard.edu
authors.forename: Angela
authors.initials: A
authors.lastname: Landrigan
authors.forename: Michael T
authors.initials: MT
authors.lastname: Wong
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Utz
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002469:Cell Separation; D018899:CpG Islands; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008024:Ligands; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D053594:Myeloid Differentiation Factor 88 / Q000276:immunology / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000276:immunology*; D051217:Toll-Like Receptor 9 / Q000276:immunology / Q000378:metabolism
chemical_list: D016207:Cytokines; D008024:Ligands; D053594:Myeloid Differentiation Factor 88; D009838:Oligodeoxyribonucleotides; D051217:Toll-Like Receptor 9