ABSTRACT
Generally, cytokines comprise a large family of secreted proteins regulating a variety of cellular functions during inflammation and immune responses. Cytokines activate immune as well as resident skin cells including keratinocytes, endothelial cells, Langerhans cells, mast cells, or fibroblasts. Subsequently, those cells release mediators that potentially communicate with sensory nerves regulating neurogenic inflammation, pain, or itch (Chung et al. 2003, 2004; Dallos et al. 2006; E et al. 2006; Grewe et al. 2000; Huang et al. 2008; Ibrahim et al. 2005; Kakurai et al. 2001; Raychaudhuri et al. 2008; Tanaka et al. 2007). In addition, immune cells (e.g., mast cells) can directly communicate with sensory nerves during inflammation and pruritus (Roosterman et al. 2006) via histamine, tryptase, prostanoids, or RL-peptides (Steinhoff et al. 2000). For example, mediators like histamine or tryptase released by mast cells during inflammation and allergic reactions can directly “talk” to sensory nerves (Steinhoff et al. 2000, 2003) and are thus targets for therapy.
