IMMUNODETECTION AND COMPARISON OF MELALEUCA, BOTTLEBRUSH, AND BAHIA POLLENS

Pollen extracts of two trees, Callistemon citrinis (bottlebrush) and M elaleuca leucadendron (melaleuca), as well as the grass Paspalum notat um (bahia) were analyzed for antigenic and allergenic cross-reactivity using SDS-PAGE and Western blotting. SDS-PAGE analysis of all three p ollen extracts revealed multiple antigenic components which were react ive with rabbit antisera made to each pollen extract. Comparison of re duced and nonreduced mobility patterns suggested the possible presence of multichain proteins linked by disulfide bonds. Clinical studies de monstrated that 81% of the patients skin test positive to at least one of the pollens were also positive to the other two. Sixty-three perce nt of allergic individuals studied showed a high correlation between s kin test results and the number of IgE-binding components analyzed by immunoblotting. These IgE-reactive components were detected in the mol ecular weight range of 29-66 kD. Western blot analysis detected more I gE-binding components in bahia pollen extracts as compared with the tr ee pollens, consistent with other reports of grass pollens being more allergenic than those from trees and weeds. Each patient's serum had a unique IgE-binding pattern, indicating heterogeneity of immune respon se; however, common major determinants were detected by a large percen tage of the allergic patient's sera.