Kinetics of allergen release from house dust mite Dermatophagoides pteronyssinus

Purified bodies of Dermatophagoides pteronyssinus were extracted over different extraction times. The release kinetics of proteins, carbohydrates, and allergens were assessed by different methods. Additional attempts have been made to elucidate the extraction process also on a molecular basis. For this purpose the extracts were analyzed by isoelectric focusing, SDS gel electrophoresis, crossed radioimmunoelectrophoresis, and an immunoprint technique. Carbohydrates, proteins, and allergens were released immediately from the mite bodies but demonstrated different release kinetics. The release of carbohydrates and proteins was linear up to 48 hours but demonstrated different slopes. The major allergen P1 demonstrated steady release up to 48 hours, whereas the overall allergenic activity as determined by RAST inhibition demonstrated typical saturation kinetics reaching a plateau after 4 to 5 hours of extraction. It was demonstrated by parallel-line assay of the RAST-inhibition curves that the allergenic determinants remained unchanged up to 48 hours. Different electrophoretic methods demonstrated that all relevant proteins and allergens were released immediately from the mite bodies. The electrophoretic patterns changed only slightly up to 4 hours. Prolonged extraction times up to 48 hours did not affect the patterns. This makes a loss of proteins or allergens by degradation unlikely.