Source characterization and molecular structure of cockroach allergens

The application of molecular cloning techniques has lead to the identification of important allergens from both German and American cockroach (Blattella germanica and Periplaneta americana). These allergens include Bla g 2 (aspartic protease) Bla g 4 (lipocalin) Bla g 5 (glutathione-S-transferase) and Per a 3 (hemocyanin). Only the Group 1 allergens Bla g 1 and Per a 1 appear to be expressed by both species. The Group 1 allergens are composed of 2-7 tandem amino acid repeats of similar to 100 amino acids and show homology to mosquito ANG12 precursor and mitochondrial energy transfer proteins. The prevalence of IgE responses to the cloned allergens ranges from 30-80 % and Bla g 2 Bla g 4 and Bla g 5 show strong skin test reactivity. High level expression systems have been developed to produce recombinant cockroach allergens in bacteria or yeast for research purposes and clinical studies. Use of the recombinant allergens will enable antibody and T cell epitopes to be identified and will allow new strategies for cockroach immunotherapy to be developed.