title: Mice vaccinated with allergen-pulsed myeloid dendritic cells are not protected from developing allergen-induced Th2 responses.
abstract: BACKGROUND
  Dendritic cells (DC) play a decisive role in the induction of allergen-induced Th1 and Th2 responses. Since the induction of allergen-specific Th1 responses has shown to inhibit allergen-induced Th2-type inflammation, in this study we investigated whether manipulated myeloid-derived DC pulsed with the specific allergen would predominantly induce allergen-specific Th1 responses thereby reducing the development of Th2 responses.
  
  
  METHODS
  Murine bone marrow (BM)-DC were generated and pulsed with ovalbumin (OVA) and CpG oligodeoxynucleotides (CpG-ODN). Langerhans cells (LC) were also isolated and pulsed in vitro with OVA. Subsequently, mice were vaccinated intravenously with either CpG/OVA-pulsed BM-DC or OVA-pulsed LC, and the protocol to induce OVA-specific Th2 responses using OVA/alum sensitization was initiated. Airway inflammation and OVA-specific serum antibody levels were evaluated 6 days after the intranasal challenge with OVA.
  
  
  RESULTS
  The application ofCpG/OVA-pulsed BM-DC was unable to reduce airway eosinophilia and inflammation in OVA/alum-immunized mice. OVA-specific IgG1 or IgE serum levels were also not reduced. The experiments using LC pulsed with OVA yielded similar results. However, mice vaccinated with CpG/OVA-pulsed BM-DC had greatly enhanced levels of serum OVA-specific IgG2a, suggesting the induction of allergen-specific Th1 responses in vivo. Moreover, allergen-induced mast cell degranulation was decreased using this approach.
  
  
  CONCLUSIONS
  Taken together, our results demonstrated that the vaccination with OVA-pulsed BM-DC matured with CpG-ODN or OVA-pulsed LC did not result in a reduction in allergen-specific Th2 responses in a murine model of severe atopic asthma. Other DC-based vaccination strategies should be evaluated in order to prevent the development of allergic disorders.
authors.affiliation: Center for Infectious Diseases, University of Würzburg, Germany. claudia.trujillo@mail.uni-wuerzburg.de
authors.forename: Claudia Milena
authors.initials: CM
authors.lastname: Trujillo-Vargas
authors.forename: José Robinson
authors.initials: JR
authors.lastname: Ramirez-Pineda
authors.forename: Alois
authors.initials: A
authors.lastname: Palmetshofer
authors.forename: Susanne
authors.initials: S
authors.lastname: Grunewald
authors.forename: Heidrun
authors.initials: H
authors.lastname: Moll
authors.forename: Christoph
authors.initials: C
authors.lastname: Berberich
authors.forename: Klaus Joseph
authors.initials: KJ
authors.lastname: Erb
mesh_terms: D000485:Allergens / Q000008:administration & dosage / Q000276:immunology*; D000818:Animals; D001483:Base Sequence; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology*; D004802:Eosinophilia / Q000628:therapy; D005260:Female; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000097:blood; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D051379:Mice; D008969:Molecular Sequence Data; D022423:Myeloid Cells / Q000276:immunology; D009838:Oligodeoxyribonucleotides / Q000008:administration & dosage / Q000276:immunology; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*; D014612:Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000485:Allergens; C408982:CPG-oligonucleotide; D016207:Cytokines; D007074:Immunoglobulin G; D009838:Oligodeoxyribonucleotides; D014612:Vaccines; D007073:Immunoglobulin E; D010047:Ovalbumin