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Lee C.C.,China Medical University at Taichung | Ho H.,Graduate Institute of Immunology | Lee K.T.,Institute of Microbiology and Biochemistry | Jeng S.T.,National Taiwan University | And 4 more authors.
Cellular and Molecular Immunology | Year: 2011

In clinical therapy, the amount of antigen administered to achieve oral tolerance for allergic diseases is large, and the cost is a major consideration. In this study, we used tobacco plants to develop a large-scale protein production system for allergen-specific immunotherapy, and we investigated the mechanisms of oral tolerance induced by a transgenic plant-derived antigen. We used plants (tobacco leaves) transgenic for the Dermatophagoides pteronyssinus 2 (Der p2) antigen to produce Der p2. Mice received total protein extract from Der p2 orally once per day over 6 days (days 0-2 and days 6-8). Mice were also sensitized and challenged with yeast-derived recombinant Der p2 (rDer p2), after which the mice were examined for airway hyper-responsiveness and airway inflammation. After sensitization and challenge with rDer p2, mice that were fed with total protein extracted from transgenic plants showed decreases in serum Der p2-specific IgE and IgG1 titers, decreased IL-5 and eotaxin levels in bronchial alveolar lavage fluid, and eosinophil infiltration in the airway. In addition, hyper-responsiveness was also decreased in mice that were fed with total protein extracted from transgenic plants, and CD4 CD25 Foxp3 regulatory T cells were significantly increased in mediastinal and mesenteric lymph nodes. Furthermore, splenocytes isolated from transgenic plant protein-fed mice exhibited decreased proliferation and increased IL-10 secretion after stimulation with rDer p2. The data here suggest that allergen-expressing transgenic plants could be used for therapeutic purposes for allergic diseases. © 2011 CSI and USTC. All rights reserved.

Hsieh L.-S.,Institute of Microbiology and Biochemistry | Yeh C.-S.,Institute of Microbiology and Biochemistry | Pan H.-C.,Institute of Microbiology and Biochemistry | Cheng C.-Y.,Institute of Microbiology and Biochemistry | And 2 more authors.
Protein Expression and Purification | Year: 2010

Phenylalanine ammonia-lyase (PAL, EC is the first committed enzyme of phenylpropanoid pathway. A PAL gene, designated as BoPAL2, was cloned from a Bambusa oldhamii cDNA library. The open reading frame of BoPAL2 was 2142 bp in size encoding a 713-amino acid polypeptide. BoPAL2 was heterologous expressed in Escherichia coli and Pichia pastoris. The recombinant proteins were exhibited PAL and tyrosine ammonia-lyase activities. The recombinant BoPAL2 had a subunit mass of 80 kDa and existed as a homotetramer. The optimum temperature and pH of BoPAL2 were 50-60 °C and 8.5-9.0, respectively. The Km and kcat values of BoPAL2 expressed in E. coli were 250 μM and 10.12 s-1. The Km and kcat values of BoPAL2 expressed in P. pastoris were 331 μM and 16.04 s-1. The recombinant proteins had similar biochemical properties and kinetic parameters with PALs reported in other plants. © 2010 Elsevier Inc. All rights reserved.

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