Antigen sampling by mucosal dendritic cells.

The mucosal immune system is the first line of defence against bacterial and viral infections and is crucial in maintaining mucosal homeostasis. In the gut, mucosal dendritic cells offer an alternative pathway to epithelial cells for antigen uptake, to initiate antigen-specific immune responses. It has recently been shown that lamina propria dendritic cells of the small intestine actively sample gut bacteria through the formation of transepithelial dendrites by a mechanism that is dependent on the expression of the chemokine receptor CX3CR1.