10 mice, TLR4-deficient (both Jackson Laboratory, Bar Harbor, ME, USA), OT-II mice (from Dr. William Heath, Melbourne), and FcγR-deficient B6 mice, purchased from Taconic (Germantown, NY, USA), were used throughout the study. FcγR-deficient mice lack the γ-chain subunit of the FcγRIII and FcεRI receptors. The

deleted γ-chain is also associated with FcγRI. The deleted γ-chain subunit is essential for receptor assembly, signal transduction and cell surface expression of FcγRIII and FcεRI molecules 32. Mice were fed with OVA-free laboratory food and tap water ad libitum, and kept in a regular 12 h dark/light cycle at a temperature of 21±2°C. All experimental procedures were performed according to a protocol approved by the appropriate governmental authority and ethics committees. The mice were sensitized with OVA (10 μg, Grade VI, Sigma, Deisenhofen, Germany) or PBS absorbed to aluminium hydroxide Selleck Caspase inhibitor (1.5 mg, Pierce

NVP-LDE225 Biotechnology, Rockford, IL, USA) by i.p. injection on days 1, 14 and 21. On days 28 and 29, all mice were challenged with 1% OVA dissolved in PBS for 20 min. Allergen exposition was performed by dispersing of the relevant agent using a jet nebulizer, LC Star, 2.8 μm mass median aerodynamic diameter (Pari, Starnberg, Germany) in a closed plexiglass box, in which mice could move freely. To generate antigen-specific Th2-biased DO11.10 cells, T cells were obtained from LN and enriched and co-cultured with purified DC from BALB/c mice pulsed with GPX6 OVA323–339 peptide (Biosyntan, Berlin, Germany) in complete medium containing IL-4, IL-2, and anti-IFN-γ. Five days later, Th2-biased DO11.10 cells were quantified and 3–4×106 were adoptively transferred i.v. into BALB/c recipients 4. On three consecutive days, mice were challenged i.n. with PBS, 100 μg rabbit anti-OVA IgG (MP Biomedicals Germany, Heidelberg, Germany) (control groups), 25 μg OVA, or OVA-IC (made by mixing a 1:4 ratio of 25 μg OVA and anti-OVA IgG). Twenty-four hours after

the last challenge, lung function was analyzed and mice were dissected. Total cell counts in BALF were scored using a Neubauer chamber (Brand, Wertheim, Germany). Leukocyte subsets (eosinophils, neutrophils, macrophages or lymphocytes) were counted in BALF using cytospins (centrifuged preparations) stained with Diff-Quik (Medion Diagnostics, Düningen, Germany). A total of 400 cells were counted in each sample. Twenty-four hours after the last airway challenge, lungs were fixed with 4% formalin and embedded in paraffin. The paraffin blocks were cut into 4 μm slices and stained with hematoxilin/eosin (Merck, Darmstadt, Germany). From each mouse lung, six sections (containing hiliar structures and periphery) of the right and left lung were evaluated. Microphotographs were performed using a Nikon Eclipse 50i microscope with a Nikon Digital Sight DS-U1 Camera.