Anti-grifolan antibody reacts with the cell wall β-glucan and the extracellular mannoprotein-β-glucan complex of C. albicans

We have recently prepared a rabbit antibody (Ab) against a fungal branched β-(1→3)-d-glucan, grifolan (GRN) obtained from Grifola frondosa. In this study, we examined the reactivity of anti-GRN Ab against a pathogenic fungus, Candida albicans. Anti-GRN Ab was strongly reacted with acetone dried, autoclaved, NaOH treated, as well as NaClO treated C. albicans, assessed by FACS. The binding was inhibited by GRN, a solubilized Candida spp. β(1→3)-d-glucan (CSBG), and a extracellular mannoprotein-β-glucan complex (CAWS). By ELISA analysis, binding affinity of anti-GRN Ab to GRN and CSBG was different. These facts strongly suggested that anti-GRN Ab reacted with the cell wall β-glucan in several ways. The Ab would be useful for the immunochemical diagnostic test of the deep-seated mycosis.