Different virulence of candida albicans is attributed to the ability of escape from neutrophil extracellular traps by secretion of DNase.

Candida albicans is an important opportunistic fungus causing both disseminated and local infections. The discovery of neutrophil extracellular traps (NETs) has presented a new strategy to kill microorganisms in host's innate immune response. Although it has been reported that NETs can trap and kill both yeast and hyphal forms of C. albicans, the mechanism by which C. albicans escape from NETs has not been fully understood. In this study, the ability of two strains of C. albicans SC5314 and 3683 to escape NETs-mediated killing was compared. It was found that SC5314 induced higher levels of reactive oxygen species (ROS) and expressions of Rac1/2 and more NETs formation by neutrophils, and also generated more deoxyribonucleases (DNase) than 3683 did. However, resistance to neutrophils killing was greater in SC5314 than that of 3683. When extracellular traps were degraded by exogenous DNase I or catalase, and neutrophil phagocytic activity blocked by cytochalasin D, the killing capacity of neutrophils co-cultured with either C. albicans SC5314 or 3683 was significantly decreased. This study indicates that C. albicans can escape from the trapping and killing of NETs by secreting DNase, which offers further insights into the basis for differences in virulence of different strains of C. albicans.