Antigens and allergens in birch pollen extract.
More than 70% of the total allergenic activity of a birch pollen (BP) extract was detected within the first 30 min of extraction. Fractionation of the BP extract by gel filtration and analysis of the eluted antigens by a fused rocket immunoelectrophoresis revealed at least three antigens with molecular weights of about 29 000, and 17 000-10 000, corresponding to antigens Nos. 7-8 and No. 2, respectively, in crossed-immunoelectrophoresis (CIE) and in crossed-radioimmuno-electrophoresis (CRIE). Gel isoelectrofocusing of the pooled allergenic fractions revealed two major protein bands with pI's around 5.6 and 5.7, probably corresponding to antigens Nos.7-8 and No. 2, respectively. Antigens Nos. 7-8 were thermoresistant, while antigen No. 2 was thermolabile. The allergenic activity was determined by prick skin testing and by the RAST inhibition method. More than 90% of the allergenic activity in the fractions was located in the protein peak C (mol. wt. 10 000-17 000) containing antigens 7-8. About 30% of the total allergenic activity of the extract (1:10 w/v) was recovered in the peak C fractions, and only less than 0.5% outside these fractions. Higher allergenic activity was obtained for the peak B fractions (mol. wt. 29 000) by skin prick testing than by the RAST. Peak B contained allergens (antigen 2) distinct from those of peak C by the CRIE and by the RAST. The allergenic material in the low molecular weight fractions of peak D (mol. wt. 2000-5000) was allergenically similar to that of peak C in the RAST. Only weak and even negative skin reactions were observed with the peak D fractions in allergic subjects.
D000485:Allergens / Q000032:analysis*; D000906:Antibodies; D000941:Antigens / Q000032:analysis*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007122:Immunoelectrophoresis / Q000379:methods; D007073:Immunoglobulin E; D007074:Immunoglobulin G; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010940:Plant Proteins / Q000032:analysis; D011058:Pollen / Q000032:analysis*; D011852:Radioallergosorbent Test / Q000379:methods; D012882:Skin Tests; D014197:Trees
D000485:Allergens; D000906:Antibodies; D000941:Antigens; D007074:Immunoglobulin G; D010940:Plant Proteins; D007073:Immunoglobulin E