Generation of high-affinity monoclonal antibodies of IgG class against native β-d-glucans from basidiomycete mushrooms

[Display omitted] •Novel monoclonal antibodies (Mabs) were raised against β-glucans from Pleurotus ostreatus.•Novel polyol-responsive Mabs were raised against native β-glucans from basidiomycete mushrooms.•Mabs recognized a conformation-sensitive epitope on several β-d-glucan molecules.•Mabs exhibited high-affinity constant (KA) for β-d-glucans from mushroom strains.•Mabs can be used for the assay of β-d-glucans in several basidiomycete strains by enzyme-linked immunosorbent assay (ELISA). β-d-glucans from basidiomycete strains are powerful immunomodulatory agents in several clinical conditions. Therefore, their assay, purification and characterization are of great interest to understand their structure-function relationship. Hybridoma cell fusion was used to raise monoclonal antibodies (Mabs) against extracellular β-d-glucans (EBGs) from Pleurotus ostreatus. Two of the hybridoma clones (1E6_1E8_B5 and 3E8_3B4) secreting Mabs against EBGs were selected. This hybridoma cell line secreted Mabs of the IgG class which were then purified by hydroxyapatite chromatography to apparent homogeneity on native and SDS-PAGE. Mabs secreted by 1E6_1E8_B5 clone were found to recognize a common epitope on several β-d-glucans from different basidiomycete strains. This Mab exhibited high affinity constant (KA) for β-d-glucans from several mushroom strains in the range of 3.20×109±3.32×103–1.51×1013±3.58×107L/mol. Moreover, they reacted to some heat-treated β-d-glucans in a different mode when compared with the native forms; these data suggest that this Mab binds to a conformational epitope on the β-d-glucan molecule. The epitope-binding studies of Mabs obtained from 1E6_1E8_B5 and 3E8_3B4 revealed that the Mabs bind to the same epitope on some β-d-glucans and to different epitopes in other antigen molecules. Therefore, these Mabs can be used to assay for β-d-glucan from basidiomycete mushrooms.