Skin-Resident Innate Lymphoid Cells - Cutaneous Innate Guardians and Regulators.

Skin is the largest barrier organ and an important interface between the body and the outside environment. Immune surveillance and homeostatic regulation of skin function are governed by complex interactions between resident lymphoid and myeloid cells and their communications with the surrounding parenchyma. Recent studies have provided exciting insights about the unique characteristics of skin-resident innate lymphoid cells (ILCs). Here, we discuss advances demonstrating how skin ILCs contribute to tissue homeostasis by regulating microbiome balance in steady-state and how their dysregulation can trigger and promote inflammatory skin diseases such as atopic dermatitis and psoriasis. We review the phenotypic and functional similarities and differences of ILCs between the skin and other organs and highlight future areas of investigation for this field.