Investigating cockroach allergens: aiming to improve diagnosis and treatment of cockroach allergic patients

Abstract

Cockroach allergy is an important health problem associated with the development of asthma, as a consequence of chronic exposure to low levels of allergens in susceptible individuals. In the last 20 years, progress in understanding the disease has been possible, thanks to the identification and molecular cloning of cockroach allergens and their expression as recombinant proteins. Assays for assessment of environmental allergen exposure have been developed and used to measure Bla g 1 and Bla g 2, as markers of cockroach exposure. IgE antibodies to cockroach extracts and to specific purified allergens have been measured to assess sensitization and analyze association with exposure and disease. With the development of the field of structural biology and the expression of recombinant cockroach allergens, insights into allergen structure, function, epitope mapping and allergen-antibody interactions have provided further understanding of mechanisms of cockroach allergic disease at the molecular level. This information will contribute to develop new approaches to allergen avoidance and to improve diagnosis and therapy of cockroach allergy.

Keywords: Asthma; Cockroach allergy; Diagnosis; Environmental exposure; Immunotherapy; Recombinant allergens.

Figure 1

Ribbon diagram of the X-ray crystal structure of rBla g 2 (gold) in complex with a Fab fragment of the mAb 4C3 (blue), superimposed to the structure of Fab’ of mAb 7C11 in complex with Bla g 2 (allergen not shown). Epitopes for both mAbs are located on opposite lobes of Bla g 2: mAbs 7C11 and 4C3 bind to the N-terminal and C-terminal lobes, respectively. Antibody fragments consist of a heavy and a light chain, in dark and light green for mAb 7C11, and in marine blue and cyan for mAb 4C3, respectively. Carbohydrates involved in mAb 4C3 binding are shown in red. The figure was prepared using the software PyMOL [90]. Note for the editors: If there are restrictions for using color in figures, then Figure 1 will be easily transformed to black and white, with the corresponding changes in the foot-of-figure.