MOLECULAR-CLONING OF GERMAN-COCKROACH (BLATTELLA-GERMANICA) ALLERGENS

Allergens produced by cockroaches (CRs) are an important cause of IgE antibody responses and asthma. Using molecular cloning and nucleic aci d hybridization techniques, we have identified and sequenced several i mportant allergens produced by the German CR (Blattella germanica) and studied their expression in the American CR (Periplaneta americana). Principal allergens include Bla g 2 (36-kD protein) and Bla g 4 (21-kD protein), to which 60-70% of CR-allergic patients make IgE antibodies . Bla g 2 is only expressed by B. germanica, whereas DNA encoding Bla g 4 is present in P americana, but is not transcribed into mRNA. Seque nce homology searches have identified Bla g 2 as an aspartic protease and Bla g 4 as a calycin. Other CR allergens that have been cloned inc lude a glutathione transferase and a troponin. These studies will enab le recombinant allergens to be expressed and used to investigate the r ole of CR allergens in asthma.