Dendritic cells and immunity to leishmaniasis and toxoplasmosis.

There is increased recognition that dendritic cells (DCs) are an important source of the IL-12 required to initiate protective immunity to protozoa, such as Leishmania and Toxoplasma. This article reviews the advances made in the last two years in understanding the pathways that lead to DC activation after infection with these organisms. Interestingly, there appear to be differences in the DC activation pathways utilized by these two intracellular protozoa which also may differ from the pathways utilized by bacteria.