Prevention of mite allergy by oral administration of Lactobacillus transformed with expression vector carrying Derf2-cDNA.

点击翻译按钮获取中文摘要

To prevent the development of mite allergy we tried to induce immune tolerance to mite allergy in mice by oral administration of heat-treated E.coli or alive lactobacillus lactis(LL) which were transformed to express Derf2 protein. Derf2-cDNA library was expressed in E.coli or LL employing an expression vector pUEX1. The clones were screened colony immunoassay employing rabbit anti-Derf2 antibody . C57BL or A/J mice were given orally Derf2- expressing or non-expressing microorganisms (10^9/day) or PBS only for 10 days. Then mice were immunized i.p. with recombinant Derf2 and boosted at 28th day. Bloods were collected at the booster day and 56days after the first immunization. IgE, IgG and IgG1 antibody titer were assayed by ELISA method. Unexpectedly, an oral administration of Derf2 protein expressing E.coli enhanced antibody formation, especially IgE in mice. Adjuvant activity of E.coli was likely due to its LPS or other cell- wall substances. E.coli was suggested to be inappropriate for oral administration, On the other hand, Derf2 expressing LL did not show any change in the antibody formation among IgE, IgG and IgG1. In the present study we could not succeed in inducing the oral tolerance in mice. One of problems was a small amount of the expression of Derf2 protein in lactobacillus. At present we investigate the proper kinds of lactobacillus, expression vectors and the insertion conditions of Derf2-cDNA.