BIOCHEMICAL, ANTIGENIC AND ALLERGENIC CHARACTERIZATION OF CRUDE EXTRACTS OF DRECHSLERA (HELMINTHOSPORIUM) MONOCERAS

In a previous study with airborne mould extracts we verified that Drec hslera (Helminthosporium) monoceras presented stronger reactions than those presented by 42 other moulds isolated in Sao Paulo city. In the present study, we evaluated the biochemical composition and the antige nicity of crude extracts obtained from vegetative and conidial stage o f D. monoceras using Czapeck broth (CB) modified and tris-HCl for extr action. The maximum values of total proteins and lipids were veri fled in the crude extract obtained in the 28th day of growth, and maximum values of carbohydrates were observed in the extracts of the 16th, 22n d and 26th days. The fractionated proteins by SDS-PAGE presented bands with molecular weights between 14.4 to 67 Kd; the 28th day extract sh owed a larger number of bands. The carbohydrates and amino acids were characterized by thin-layer chromatography. The antigenicity of the cr ude extracts was verified by immunodiffusion reaction in agar against rabbit hyperimmune sera. Precipitation lines were observed in all stud ied extracts and common antigenic molecular populations. Based on the above results, the 28th day extract was selected to verify the inducti on of IgE antibody responses in immunizations of Balb/c and cAF-1 mice , and titer by passive cutaneous anaphylaxis test using Wistar rats, T he maximum titers obtained were 160 in cAF-1 mice and 1.280 in Balb/c mice. The results suggest that the 28th day extract contains allergeni c fractions and should be chosen for future studies related to fractio nation, characterization and standardization in diagnostic methods and immunotherapy.