Functionality of the human antibody response to <i>Candida albicans</i>

<i>Candida albicans</i> is a common commensal on human mucosal surfaces, but can become pathogenic, e.g. if the host is immunocompromised. While neutrophils, macrophages and T cells are regarded as major players in the defense against pathogenic <i>C. albicans</i>, the role of B cells and the protective function of their antibodies are less well characterized. In this study, we show that human serum antibodies are able to enhance the association of human THP-1 monocyte-like cells with <i>C. albicans</i> cells. Human serum antibodies are also capable of inhibiting the adherence and damage dealt to epithelial cells. Furthermore, human serum antibodies impair <i>C. albicans</i> invasion of human oral epithelial cells by blocking induced endocytosis and consequently host cell damage. While aspartic proteases secreted by <i>C. albicans</i> are able to cleave human IgG, this process does not appear to affect the protective function of human antibodies. Thus, humans are equipped with a robust antibody response to <i>C. albicans</i>, which can enhance antifungal activities and prevent fungal-mediated epithelial damage.