Fungal cell wall dynamics and infection site microenvironments: signal integration and infection outcome

Abstract

Upon entrance into the host, fungi encounter a myriad of host effector products and microenvironments that they sense and adapt to for survival. Alterations of the structure and composition of the cell wall is a major fungal adaptation mechanism to evade these environments. Here we discuss recent findings of host-microenvironmental induced fungal cell wall changes, including structure, composition, and protein content, and their effects on host immune responses. A take home message from these recent studies is an emerging understanding of how integration of multiple signals, of both fungal and host responses to dynamic infection site microenvironments, determines outcomes of infection. A challenge moving forward is to further understand these mechanisms and harness them for therapeutic benefit.

Figure 1

Potential Responses of the Fungal Cell wall to Signals encountered in infection site microenvironments. The diagram presents the various signals that are known to occur in vivo during fungal pathogenesis and the potential responses of the fungal cell wall in Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. The diagram highlights the complexity of in vivo microenvironments and the number of signals that the invading fungus must integrate into the subsequent response. A challenge moving forward is to understand these in vivo microenvironments and how signal integration leads to disease outcome.