Evaluation of allergenicity of acid-hydrolyzed wheat protein using an in vitro elicitation test.

BACKGROUND: We performed an in vitro elicitation test to determine the ability of different types of wheat-allergic patients' IgE to induce humanized mast cell activation after the addition of various time-treated acid-hydrolyzed wheat proteins (HWPs). METHODS: The reactivity of heat- and various time-treated acid-hydrolyzed glutens (acid-HGs) and commercial acid-HWP (HWP1), using serum IgE from wheat allergy accompanied by skin and rhinoconjunctival sensitization to HWP1 in the facial soap, pediatric subjects with food allergy to native wheat, adult wheat-dependent exercise-induced anaphylaxis subjects, and nonatopic healthy subjects, was elucidated by dot blot and a luciferase assay-based in vitro elicitation test (EXiLE test). RESULTS: Serum from subjects sensitized with HWP1 reacted only to acid-HGs (acid-HGs treated for 0.5-3 or 6 h), but not native gluten, in the results of the dot blot. In contrast, sera from pediatric subjects sensitized with native wheat reacted to native gluten more strongly and showed only slight reactions to 0.5- to 1-hour-treated acid-HGs. The results of the in vitro elicitation test showed that acid hydrolyzation of the gluten attenuated antigen-induced luciferase expression in a time-dependent manner for sera from native-wheat-sensitized pediatric subjects. On the other hand, in the sera from HWP1-sensitized subjects, acid hydrolyzation of the gluten for 0.5 h dramatically increased luciferase expression. CONCLUSIONS: Even after prolonged hydrolyzation, acid-HGs still retained the ability to activate mast cells in the case of HWP1-sensitized subjects.

Primary structure of potential allergenic proteins in emu (Dromaius novaehollandiae) egg white.

The emu (Dromaius novaehollandiae) egg is considered promising as an alternative egg product. To obtain basic biochemical information on emu egg white, the major protein compositions in emu and chicken egg whites and the primary structures of potential allergenic proteins were compared. The dominant protein in emu egg white was ovotransferrin (OVT), followed by ovalbumin (OVA) and TENP protein. The OVA and ovomucoid (OVM) levels in emu egg white were estimated as significantly lower than those in chicken egg white by Western blotting and enzyme-linked immunosorbent assays using anti-chicken OVA or OVM antibodies. Lysozyme and its enzymatic activity were not detected in emu egg white. OVT, OVA, and OVM genes were also cloned, and their nucleotide and amino acid sequences were determined. The protein sequences of OVT, OVA, and OVM from emu showed lower similarities to those of chicken than other avian species, such as quail and turkey. These results emphasize the low allergenicity of emu egg white and its potential as an alternative to chicken egg white.

Rush specific oral tolerance induction in school-age children with severe egg allergy: one year follow up.

BACKGROUND: At present, the only treatment for food allergy is to avoid the allergy-causing food. Some trials of specific oral tolerance induction (SOTI) have been carried out, but the rate of tolerance induction was low despite long treatment periods, at least 3 months to several years. A new type of treatment is long desired. The objectives of this study are to perform our rush SOTI for school-age patients with severe egg allergy, and to evaluate the safety and efficacy of this method for one year. METHODS: Six school-age children (7-12 years of age) with severe IgE-mediated egg allergy confirmed by double-blind, placebo-controlled food challenge (DBPCFC) underwent rush SOTI, in which patients ingested increasing doses of egg several times every day. After rush SOTI, patients ingested the maintenance dose of egg at least twice a week. RESULTS: In DBPCFC, the median threshold dose of egg white inducing allergic reactions was 0.152 g (0.012-0.360 g). All subjects acquired tolerance to more than one whole egg (60 g). It took only 12 days (9-18 days). None experienced any serious reaction. We observed a decrease in IL-10 and an increase in TGF-beta1 at 6 months and a decrease in egg-specific IgE and an increase in egg white-specific IgG4 at 12 months after rush SOTI in blood. All subjects have been able to ingest more than one whole egg ever since. CONCLUSIONS: Our rush SOTI is a safe and effective treatment for severe food allergy since only a few weeks are needed to acquire tolerance. It would replace allergen avoidance as the treatment for food allergy.

Effect of polyethylene glycol and dimethyl sulfoxide on the fusion of bovine nuclear transfer using mammary gland epithelial cells.

The effects of polyethylene glycol and dimethyl sulfoxide (PEG/DMSO) treatment of donor cells on the fusion and subsequent development of bovine nuclear transfer embryos using mammary gland epithelial (MGE) cells before electrofusion (fresh MGE cells) was studied. The same study was conducted on those cells that were frozen and stored in liquid nitrogen, and then thawed (frozen-thawed MGE cells). Experiment 1 showed that the exposure time and pH of PEG/DMSO solution affected the fusion of nuclear transfer, and that a higher fusion rate was obtained when fresh MGE cells were exposed to PEG/DMSO solution at pH 8.0 for 5 min. In Experiment 2, the proportion of fused oocytes with fresh PEG/DMSO-treated cells (70 +/- 6%) was significantly higher than that with non-treated cells (50 +/- 13%, p < 0.05). The same tendency was observed when frozen-thawed cells as donor nuclei were used (48 +/- 6% vs. 34 +/- 12%, p < 0.05). In addition, PEG/DMSO treatment has neither harmful nor beneficial effects on the cleavage and development of the blastocyst stage of reconstructed embryos (p > 0.05). The fusion and cleavage rates of frozen-thawed cells were significantly lower than those of fresh cells (p < 0.05). After 10 blastocysts, derived from fresh PEG/DMSO-treated cells, were transferred to five recipient heifers, one live female calf was obtained. Experiment 3 showed that PEG/DMSO treatment reduced the viability of both fresh and frozen-thawed MGE cells (p < 0.05). We conclude that the PEG/DMSO treatment of fresh MGE cells, as well as the frozen-thawed cells, before electrofusion has a positive effect on the fusion of nuclear transfer without decreasing the in vitro development of reconstructed embryos.