Immunobiology of dendritic cells in the rat.

Dendritic cells (DC) are crucial orchestrators of the adaptive immune response. They are highly effective antigen samplers and have a unique ability amongst antigen presenting cells to activate naïve T lymphocytes and subsequently direct the quality of the immune response. Understanding how DC initiate and regulate immune responses requires in-depth knowledge of DC function at cellular and molecular levels. Research on the biology of DC has predominantly used in vitro-generated and ex vivo-isolated DC from mice and humans. It is, however, often difficult to relate such DC to those that actually exist in vivo. The model we have developed in the rat permits analysis of DC in a near-physiological setting, and provides a description of DC biology that other systems must take into account. In this review we focus on our own research on DC in the gastro-intestinal tract, covering a variety of concepts in DC biology, and relate our findings to the work of others, to provide an overall picture of what is known regarding the nature of this complex cell type in the rat.