Transgenic rice for allergy immunotherapy
- Shengwu Ma*,† and
- Anthony M. Jevnikar*,‡,§,¶,∥
- *Lawson Health Research Institute, ‡Robarts Research Institute, †Department of Biology, and§Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada N6A 5B8; and¶London Health Science Centre, 339 Windermere Road, A10-113, London, ON, Canada N6A 5A5
Allergic reactions represent exaggerated or inappropriate adaptive responses to a wide variety of environmental triggers. These hypersensitivity reactions typically involve the skin, respiratory tract, and gut. Allergy is a significant health problem; it currently affects >15% of children and adults worldwide and is rising in incidence (1). Allergy appears to be a major factor in the pathogenesis of most asthma and rhinitis, especially in children and young adults (2). Allergies can adversely affect the quality of life, and reactions to inhaled or ingested allergens can be severe and can lead to death. Although a number of immune factors participate in allergy, interaction of IgE antibody with mast cells that express high-affinity IgE receptors (FcεR1) is central to the most severe and immediate form of hypersensitivity (type I). Allergen-specific IgE attachment predisposes mast cells to activation, because contact with multivalent allergen crosslinks surface-bound IgE and leads to the release of inflammatory autocoids, including histamine (3). Current therapies such as corticosteroids and bronchodilators are nonspecific and expensive and are associated with adverse side effects (4). For these reasons, there has been an urgent search for more effective and specific therapies, including neutralization of IgE with monoclonal antibody (omalizumab) (5) and targeting of inflammatory cytokines and chemokine receptors (6). Although these strategies hold promise, they focus primarily on inhibiting effector phases of allergy, whereas prevention of allergy would likely be more effective. The article by Takagi et al. (7) in this issue of PNAS is timely, because it presents an approach using transgenic rice to express and orally deliver specific peptide epitopes of tree pollen allergens to attenuate the development of allergic immune responses and inhibit allergen-specific IgE production. Because this approach is specific, is unlikely to be harmful, is cost-effective, and might be applied to other immune-mediated immune diseases, it holds …
