SPR biosensor chip based on mannan isolated from Candida dubliniensis yeasts applied in immunization effectiveness testing

Abstract Study of interactions of glycan structures with glycan binding proteins attracts considerable attention due to their key significance in the processes of viral and bacterial pathogenesis, the innate immunity and the protection against infectious and communicable diseases. Here we describe the development of SPR biosensor based on mannan isolated from Candida dubliniensis yeasts, biotinylated and immobilized on a streptavidin-modified SPR chip with polycarboxylate matrix. The biosensor response was linear up to 16 nM of Concanavalin A (Con A) lectin with the limit of detection of 0.1 nM and response time from 2 minutes. SPR biosensor was applied in evaluating the efficiency of the immunization against C. dubliniensis in the animal model by the measurement of rabbit sera taken from animals immunized by mannan, killed yeast cells and mannan-albumin conjugate. Anti-mannan antibodies were quantified by ELISA in microplate modified with Con A and mannan. Based on calculated apparent half-life (t1/2app) for the interaction of antisera with mannan SPR biosensor we proved that the immunization with the mannan conjugate was the most efficient method producing mannan specific immunoglobulins with the highest affinity to mannan of C. dubliniensis.