RAT URINARY PROTEINS BINDING HUMAN IGE DETECTED BY CHEMILUMINESCENCE

Work with laboratory animals involves the increased risk of developing an allergy. Certain proteins in male rat urine have been shown to be major allergens, i.e., Rat n 1.01 and Rat n 1.02. Rat urinary proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresi s (SDS-PAGE) were electroblotted to polyvinylidene difluoride (PVDF) m embranes. Immunoblot analysis of human IgE binding components in rat u rine utilizing chemiluminescence and a newly developed luminometer is described, Luminometer scanning curves of IgE reactivity to the separa ted rat urinary proteins are demonstrated. Rat allergic individuals sh owed different immune responses to the separated proteins. Rat n 1.02, also known as the major protein alpha 2u-globulin, was not always the dominant allergen. Another protein in the albumin region, 60-67 kDa, was found to be an important allergen to some rat-sensitive subjects. Reactivity in the skin prick test with purified Rat n 1.01 and Rat n 1 .02 fractions were strong. However, in dot blot under nondenaturing co nditions, only weak responses were obtained to the purified rat urinar y proteins except for the albumin fraction. Chemiluminescence measurem ents in blotting membranes of patient IgE bound to different dilutions of certain rat urine proteins revealed good quantitative relationship s. Three different chemiluminescence substrates were tested. Measureme nt of IgE bound to individual allergens as well as the abundance and r elative importance of various allergens were studied.