After selection with G418 we performed

PCR screening (PCR: 5-tcaacctacaaacggaaagaa and 5′-ctaaacccaaacacagaccta). As a PCR control we cloned a similar genomic fragment of the IgG1 region in front of IgE. The test-arm fragment was 155 bp longer, as the actual target vector region, in order to avoid PCR contaminations (Supporting Information Fig. 4). The expected PCR size for controls is 1050 bp and for correct integration of the target vector is 895 bp (Supporting Information Fig. 4). Then, we verified positive clones by southern blots using an external genomic probe (Fig. 1A). Three independent positive clones were injected and chimeric offspring was bred to Deleter mouse strain on the 129Sv genetic background [42]. Testing of the Cre-deletion was done using the primers:

5′-atgggagtttctgtgattct Selleck FK506 and 5′-gcccagaaggataagaaaac for the IgE knock-in (PCR-B, 590 bp) (Fig. 1A). After Cre deletion backcrossing for nine generations to C57BL/6 was performed. Some of these mice were then mated to CD23-deficient mice [23] on a C57BL/6 background. All studies with mice were performed in accordance with German animal experimentation law. Immunoglobulin isotype-specific ELISA was done using goat anti-mouse immunoglobulin anti-sera (Southern Biotech, USA) except for IgE detection, which was done with monoclonal anti-IgE antibodies 84.1C and EM95.3 [43, 44] and total murine IgG, which was done by goat anti-mouse IgG (Jackson, USA). For antigen-specific find more ELISAs, we coated with 10 μg/mL TNP-OVA. We used pooled sera

from immunized mice as a standard and titrated the samples in serial dilutions and gave the titers of specific Igs as relative Units/mL. Anti-CD23 (B3B4, BD Biosciences, USA), anti-CD45RB-B220, anti-IgG1 (Clone A85-1, BD or RMG1-1, Biologend) and anti-IgE (Clone23G3, BD; or EM95.3) FITC and PE-labeled antibodies were used in FACS analysis on cells that have been preincubated with mouse IgG as Fc block (Jackson Immuno Research, USA) on a FACScalibur (BD Biosciences, USA). For the detection of surface IgE and IgG1 after N. brasiliensis infection, mesenteric lymph node cells were prepared by mechanical disruption in 70 μm cell strainers (BD Falcon) and washed with an acid buffer (0.085 M NaCl, 0.005 Epothilone B (EPO906, Patupilone) M KCl, 0.01 M EDTA, and 0.05 M NaAcetate (pH 4)) to remove extrinsic IgE bound to CD23. For the detection of mouse mast cell protease-1 (MMCP-1) in plasma of anaphylactic mice, we used an ELISA kit (eBiosciences, USA) according to the manufacturer. In vitro antibody production was examined in total spleen cells stimulate with 20 μg/mL LPS, with and without IL-4 (Peprotech, USA) for 4–5 days. For antigen-specific immune response 3-month old mice were sensitized by injection with 100 μg TNP-OVA (Biosearch Technologies, USA), precipitated with alum (Serva, Heidelberg, Germany), subcutaneously and i.p. After 14 days mice received a similar booster injection.