Recombinant allergens for diagnosis and therapy of allergic disease

Many of the problems associated with using natural allergenic products for allergy diagnosis and treatment can be overcome with use of genetically eng ineered recombinant allergens. Over the past 10 years, the most important a llergens from mites, pollens, animal dander, insects, and foods have been c loned, sequenced, and expressed. In many cases the three-dimensional allerg en structure has been determined and B-cell and T-cell epitopes have been m apped. These studies show that allergens have diverse biologic functions (t hey may be enzymes, enzyme inhibitors, lipocalins, or structural proteins) and that as a rule the allergen function is unrelated to its ability to cau se IgE antibody responses, High-level expression systems have been develope d to produce recombinant allergens in bacteria, yeast, or insect cells. Rec ombinant allergens show comparable IgE antibody binding to their natural co unterparts (where available) and show excellent reactivity on skin testing and in in vitro diagnostic tests. Cocktails of recombinant allergens can be formulated with predetermined and uniform allergen levels, which could rep lace natural allergens and result in the development of innovative, patient -based tests for allergy diagnosis. Recombinant allergens also offer the ex citing possibility of developing new forms of allergen immunotherapy, inclu ding the use of hypoallergens, allergens coupled to IgE suppressive adjuvan ts, and peptide-based therapies. The production of recombinant allergens as defined molecular entities makes it feasible to consider the possibility o f developing prophylactic allergen vaccines. The introduction of recombinan t allergens in research and in clinical trials should lead to significant i mprovements in allergy diagnosis and treatment.