ABSTRACT
Keratinocytes support the initiation and amplification of skin inflammatory and immune responses through the regulated expression of an array of mediators. Keratinocytes cultured from nonlesional skin of atopic dermatitis (AD) patients produce higher amounts of certain cytokines and chemokines compared to keratinocytes cultured from nonatopic subjects. Exaggerated release of these factors can be important for enhanced recruitment as well as sustained survival and activation of inflammatory cells, including dendritic cells and T lymphocytes. Recent evidence indicates that AD keratinocytes have a dysregulated activity of activator protein (AP)-1 transcription factors, which can help to explain the abnormal expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) and other cytokines and suggests the existence of molecular mechanisms targeting atopic inflammation to the skin of AD patients. In this chapter we outline current knowledge supporting the concept that keratinocytes actively contribute to the pathogenesis of AD.
