Epithelial cytokines in soil-transmitted helminth infections.

Epithelial barriers are critical in our interaction with the outside world. They mediate gas exchange in the lung, nutrient absorption in the gut and provide a barrier against pathogen entry throughout the body. Until relatively recently, these mechanical barrier functions were thought to represent the primary mechanism by which the epithelium protects against infection; however, current research is unveiling a broad range of interactions between epithelial barrier cells and the immune response. This Chapter reviews current evidence that the epithelium is central to the immune response to soil-transmitted helminths, with a focus on the cytokines and other mediators that epithelial cells produce. We compare and contrast the cellular sources and initiating factors that lead to epithelial cytokine production, the role of the epithelium in ejecting and killing parasitic worms, and the techniques by which these parasites counteract the activities of the epithelium.