Interaction with immune cells

Phagocytes such as macrophages and neutrophils are key players of the innate immune system and represent a crucial line of defense against pathogenic Candida species such as C. albicans and C. glabrata. This is particularly illustrated by the fact that invasive Candida infections rarely occur in healthy hosts, and a compromised immune system is one of the major predisposing factors for disease.

Recognition of Candida cells by phagocytes leads to cytokine production, phagocytosis, and the activation of antimicrobial effector functions to induce killing of the fungus. On the other hand, pathogenic Candida spp. are well adapted to their host and have developed mechanisms to evade or counteract the anti-microbial activities of phagocytes. One of these mechanisms is the adaptation of fungal metabolism to cope with nutrient limitation inside the phagosome. This and other strategies allow C. albicans and C. glabrata to not only survive phagocytosis by macrophages, but even proliferate intracellularly and escape. C. albicans escapes by rapid hyphal growth and host cell damage. In contrast, C. glabrata replicates as yeast cells inside macrophages and persists for days, before macrophages burst and fungal cells are released.

We want to characterize the interaction of C. albicans, C. glabrata, and C. auris with phagocytes. We are especially interested in the fungal factors and activities that help Candida to cope with these immune cells, survive and escape. Moreover, in close collaboration with the Junior Research Group Adaptive Pathogenicity Strategies we investigate how immunotherapy impacts on the interactions between C. albicans and macrophages and mitigates escape of C. albicans from macrophages. Therapies that aim at improving the innate immune system are increasingly recognized as essential in improving the outcome of fungal infections. Particularly interferon-γ is a promising candidate due to its potential of improving macrophage microbicidal activity.