Dendritic cells in immunity and tolerance-do they display opposite functions?

It was recently proposed that cells of the dendritic family not only control immunity but also maintain tolerance to self-antigens, two complementary functions that would ensure the integrity of the organism in an environment full of pathogens. As they express a variety of receptors that specifically recognize microbial products, DCs are able to discriminate between self and nonself and may therefore enable the immune system to mount potent effector activity to pathogens while silencing self-reactive lymphocytes.