A review of cloned allergens

Recently, several allergens have been expressed in bacteria by cloned DNA. By helping to define the aminoacid sequences of the polypeptide chains of the most relevant allergens, the use of recombinant DNA technology has paved the way to structure function studies on the role of allergens in the regulation of immune response. At the same time, the close look at the structure achieved has revealed the presence, not uncommon in nature, of distinct related genes: the question of defining their relationship with isoforms of natural allergens is open. The present review discuss some of these problems.