Antifungal and antitumor activities of a monoclonal antibody directed against a stress mannoprotein of Candida albicans

Immunization of mice with a stress mannoprotein of >200 kDa from the cell wall of Candida albicans led to the production of monoclonal antibody (Mab) C7. The immunogen is a major target of secretory IgA and its expression is regulated by different environmental conditions including temperature, pH, glucose concentration and ammonium sulphate in the culture medium. Mab C7 reacted with a peptide epitope present in the >200 kDa antigen as well as in a number of antigens from the blastoconidium and germ tube cell wall, including enolase. In addition to its reactivity with C. albicans, Mab C7 also reacted with antigens present in C. krusei, C, tropicalis, C. glabrata, C. dubliniensis and C. lusitaniae, as well as in Cryptococcus neoformans, Scedosporium prolificans and Aspergillus fumigatus. Mab C7 exhibited four important biological activities, namely inhibition of adhesion of C. albicans to a variety of surfaces, inhibition of germination of C. albicans, direct candidacidal activity and direct tumoricidal activity. In tumor cells, Mab C7 reacted with nucleoporin Nup88, a reactivity that can be utilized for diagnostic and prognostic purposes.