Skin immunity and inflammation: cellular interactions and communication.

The skin is a vital organ that protects organisms from external insults, providing a barrier to the outside environment. The cellular system of the skin consists of highly specialised immune and non-immune cells, which are equipped to respond promptly, providing effective immunity and restoring tissue homeostasis. Well-coordinated cellular communication involves cells and soluble factors, which are essential for maintaining the balance and protecting the skin from inflammatory skin diseases, impaired tissue repair and recurring infections. In this review, we will focus on the recent development of understanding how cellular networks orchestrate skin immunity via a coordinated communication system of soluble factors and their signalling pathways, with a focus on psoriasis as a model of inflammatory skin disease.