Migration of dendritic cells across blood and lymphatic endothelial barriers.

Dendritic cells (DC) are professional antigen presenting cells which play a pivotal role in the activation of adaptive immunity. Tissue invasion by pathogens induces the recruitment of blood DC to the site of infection and contributes to their subsequent migration to secondary lymphoid organs. This complex process relies on the expression and regulation of receptors for chemotactic factors on the surface of migrating DC and on the activation of adhesion molecules which allow DC to properly interact with both blood and lymphatic vessels. In the absence of correct tissue localization, DC fail to promote proper immune responses. Therefore, the interaction of DC with endothelial cells represents a fundamental step for DC biology.