Hypersensitivity to Ascaris Antigens

Abstract

Abstract An Ascaris suum allergen was obtained in purified form by a combined procedure employing Sephadex gel filtration and polyvinyl chloride block electrophoresis. The purity of the allergen (Asc-1) was confirmed by polyacrylamide gel electrophoresis, immunoelectrophoresis, sedimentation pattern in the ultracentrifuge and isoelectric focussing. The molecular weight of Asc-1 ranged from 17,000 (as determined by sedimentation equilibrium) to 19,000 (as determined by Sephadex G-100 gel filtration) and the sedimentation coefficient was 1.8S. The allergen was negatively charged (pI = 4.8 to 5), contained 8.6% reducing sugars and dissociated into subunits of equal molecular weight in polyacrylamide gel in the presence of sodium dodecyl sulfate. The amino acid analysis showed high glutamic acid, aspartic acid, and lysine content, and absence of half-cystine, methionine, and amino sugars. The allergen stimulated the production of reaginic (Hc) antibodies in Bordetella pertussis-treated rats, and as little as 10-8 to 10-9 µg of Asc-1 elicited positive P-K reactions in rats passively sensitized with rat anti-Ascaris reaginic sera.