Analysis of the allergenic components of Hinoki cypress (Chamaecyparis obtusa) pollen by immunoblotting with the sera from patients with Japanese cedar pollinosis

ABSTRACT The polypeptides in Hinoki cypress ( Chamaecyparis obtusa ) and Japanese cedar ( Cryptomeria japonica ) extracts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and then IgE binding activities were examined by immunoblotting using sera from 25 patients with Japanese cedar pollinosis. Fifteen component bands with IgE binding abilities were detected. The most frequent IgE binding band was observed on the line of 45 kDa (92%), followed by 50 (88%) and 74 kDa (52%). The immunoblotting profile of Hinoki cypress was different from that of Japanese cedar. In the inhibition immunoblotting test, IgE binding activities of 14, 30–35 and 74–85 kDa components in Japanese cedar extract and 14, 30–35 and 60–74 kDa proteins in Hinoki cypress extract were completely inhibited with heterologous extracts. However, those of the 41 kDa proteins and 46 kDa in Japanese cedar extract and 45 and 50 kDa components in Hinoki cypress extract were partially inhibited. These data suggest that 45 and 50 kDa components of Hinoki cypress and 41 and 46 kDa components of Japanese cedar share some cross-reacting and specific epitopes.