title: Differential activation of dendritic cells by toll-like receptors causes diverse differentiation of naïve CD4+ T cells from allergic patients.
abstract: BACKGROUND
  To avert the differentiation of allergen-specific Th2 cells in atopic individuals is a major goal in the prevention and therapy of IgE-mediated allergy. We aimed to compare different toll-like receptor (TLR) agonists regarding their effects on antigen-presenting cells and the differentiation of naïve T cells from allergic patients.
  
  
  METHODS
  Monocytes and monocyte-derived dendritic cells (mdDC) from allergic patients were stimulated with Pam3CSK4 (TLR1/2 ligand), FSL-1 (TLR2/6 ligand), monophosphoryl lipid (MPL)-A, lipopolysaccharide (LPS, both TLR4 ligands), and flagellin (TLR5 ligand). Allergen uptake and upregulation of CD40, CD80, CD83, CD86, CD58, CCR7 and PD-L1 were analyzed by flow cytometry. Functional maturation of mdDC was tested in mixed leukocyte reactions, and the synthesis of proinflammatory cytokines, IL-10 and members of the IL-12 family was assessed. TLR-ligand-activated mdDC were used to stimulate naïve CD4(+) T cells, and cytokine responses were assessed in supernatants and intracellularly.
  
  
  RESULTS
  All TLR ligands except flagellin enhanced allergen uptake. All TLR ligands induced functional maturation of mdDC with differential expression of surface molecules and cytokines and promoted the differentiation of IFN-γ-producing T cells. LPS-matured mdDC exclusively induced Th1-like responses, whereas mdDC stimulated with the other TLR ligands induced both Th1- and Th0-like cells. Pam3CSK4 and flagellin additionally induced Th2-like cells. Th1-like responses were associated with higher expression levels of co-stimulatory molecules, PD-L1, IL-6, TNF-α, and IL-12p70. None of the TLR-ligand-stimulated mdDC induced IL-10- or IL-17-producing T cells.
  
  
  CONCLUSIONS
  Different TLR ligands differently influence T-cell responses due to varying activation of the three signals relevant for T-cell activation, that is, antigen presentation, co-stimulation and cytokine milieu.
authors.affiliation: Christian Doppler Laboratory for Immunomodulation, Medical University of Vienna, Vienna, Austria; Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Deifl
authors.forename: C
authors.initials: C
authors.lastname: Kitzmüller
authors.forename: P
authors.initials: P
authors.lastname: Steinberger
authors.forename: M
authors.initials: M
authors.lastname: Himly
authors.forename: B
authors.initials: B
authors.lastname: Jahn-Schmid
authors.forename: G F
authors.initials: GF
authors.lastname: Fischer
authors.forename: G J
authors.initials: GJ
authors.lastname: Zlabinger
authors.forename: B
authors.initials: B
authors.lastname: Bohle
mesh_terms: D000485:Allergens / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D000954:Antigens, Surface / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D002454:Cell Differentiation; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology* / Q000378:metabolism*; D016130:Immunophenotyping; D008024:Ligands; D008213:Lymphocyte Activation / Q000276:immunology; D010641:Phenotype; D051193:Toll-Like Receptors / Q000378:metabolism*
chemical_list: D000485:Allergens; D000954:Antigens, Surface; D016207:Cytokines; D008024:Ligands; D051193:Toll-Like Receptors
keywords: T-cell differentiation; cytokines; dendritic cells; innate immune system; toll-like receptor
references.citation: Nat Rev Immunol. 2006 Oct;6(10):761-71
references.pmid: 16998509
references.citation: J Biol Chem. 2001 Oct 5;276(40):37692-9
references.pmid: 11477091
references.citation: J Allergy Clin Immunol. 2013 Mar;131(3):875-85
references.pmid: 23265862
references.citation: J Exp Med. 2001 Apr 2;193(7):839-46
references.pmid: 11283156
references.citation: Eur Ann Allergy Clin Immunol. 2010 Jun;42(3):115-9
references.pmid: 20648774
references.citation: N Engl J Med. 2006 Oct 5;355(14):1445-55
references.pmid: 17021320
references.citation: Immunol Lett. 2009 Aug 15;125(2):114-8
references.pmid: 19555720
references.citation: Trends Immunol. 2003 Apr;24(4):207-12
references.pmid: 12697453
references.citation: Allergol Immunopathol (Madr). 2003 Sep-Oct;31(5):270-7
references.pmid: 14572416
references.citation: Allergy. 2012 May;67(5):593-600
references.pmid: 22188598
references.citation: J Exp Med. 1995 Nov 1;182(5):1591-6
references.pmid: 7595230
references.citation: Eur J Immunol. 1999 Jul;29(7):2344-53
references.pmid: 10427997
references.citation: Eur J Immunol. 2004 May;34(5):1371-80
references.pmid: 15114670
references.citation: J Immunol. 2003 Nov 15;171(10):4984-9
references.pmid: 14607893
references.citation: Clin Exp Immunol. 2010 Jun;160(3):403-10
references.pmid: 20345983
references.citation: J Immunol. 2001 Sep 15;167(6):3107-13
references.pmid: 11544295
references.citation: Clin Exp Allergy. 2007 Mar;37(3):381-90
references.pmid: 17359388
references.citation: J Immunol. 1995 Feb 15;154(4):1932-40
references.pmid: 7530747
references.citation: Nat Rev Immunol. 2003 Feb;3(2):133-46
references.pmid: 12563297
references.citation: Int Arch Allergy Immunol. 2011;155(1):31-7
references.pmid: 21109746
references.citation: J Exp Med. 2004 Jun 7;199(11):1567-75
references.pmid: 15173208
references.citation: J Allergy Clin Immunol. 2010 Mar;125(3):711-8, 718.e1-718.e2
references.pmid: 20132976
references.citation: Blood. 2006 Sep 1;108(5):1435-40
references.pmid: 16684955
references.citation: Int Arch Allergy Immunol. 2009;149(3):231-8
references.pmid: 19218815
references.citation: Allergy. 2005 May;60(5):678-84
references.pmid: 15813815
references.citation: J Immunol. 2004 Jun 1;172(11):6922-30
references.pmid: 15153511
references.citation: Nat Med. 2012 Nov;18(11):1705-10
references.pmid: 23064463
references.citation: Immunity. 2009 Jun 19;30(6):766-75
references.pmid: 19538928
references.citation: Int Arch Allergy Immunol. 2011;154(4):336-44
references.pmid: 20975285
references.citation: Allergy. 2001 Jun;56(6):498-505
references.pmid: 11421893